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125 Years
Deutsche Botanische Gesellschaft
Botanikertagung
University of Hamburg
September 3-7, 2007
Poster
Abstract Book
CONTENTS
CONTENTS |
INFORMATION FOR AUTHORS ........................................................... 2
POSTER ABSTRACTS ......................................................................... 3
P01: BIODIVERSITY IN AFRICA................................................ 3
P02: BIOTECHNOLOGY AND SOCIETY ..................................... 5
P03: CELL - TREE - TIMBER .................................................... 5
P04: DEVELOPMENTAL BIOLOGY ........................................... 9
P05: EARLY LAND PLANTS ..................................................... 15
P06: ECOLOGY AND ECOPHYSIOLOGY OF ALGAE................... 16
P07: EVOLUTION OF ALGAE .................................................... 20
P08: GENETICALLY MODIFIED CROP PLANTS ........................ 22
P09: GRAVITATION BIOLOGY ................................................. 24
P10 HALOPHYTES ................................................................... 25
P11 HISTORY OF BOTANY ....................................................... 25
P12 LICHENS ........................................................................... 26
P13 MEMBRANE TRANSPORT ................................................. 27
P14 MOLECULAR PHYSIOLOGY OF ALGAE ............................. 35
P15 N/S METABOLISM ............................................................ 38
P16 OBSERVATION OF DESERTIFICATION ............................... 41
P17 ORGANELLES ................................................................... 42
P18 PHOTOSYNTHESIS AND ASSIMILATION ............................ 52
P19 PHYTOHORMONES – METABOLISM AND FUNCTION ........ 60
P20 PLANT GENOMICS ............................................................ 65
P21 PLANT INVASIONS ............................................................ 68
P22 PLANT PATHOGENS .......................................................... 69
P23 PLANT PHYLOGENY ......................................................... 75
P24 FLORAL DIVERSITY .......................................................... 78
P25 PLANT-ANIMAL INTERACTION ........................................ 79
P26 PLANT-MICROBE SYMBIOSIS ........................................... 81
P27 PLANT-VIRUS INTERACTION ............................................ 84
P28 RADIATION AND SPECIATION........................................... 85
P29 REACTIVE OXYGEN.......................................................... 89
P30 REDOX REGULATION ....................................................... 91
P31 SECONDARY METABOLISM .............................................. 95
P32 SENSING IN PLANTS ......................................................... 105
P33 SEXUAL PLANT REPRODUCTION ...................................... 110
P35 TROPICAL ECONOMIC PLANTS ......................................... 111
P36 WETLAND ECOLOGY........................................................ 113
INDEX OF AUTHORS.......................................................................... 115
CONTENTS
1
INFORMATION FOR AUTHORS
POSTERS
|
Maximal poster size should be DIN A0 portrait size (84,1 cm width x 118,9
cm height). Material to fix the posters to the panels is available at the posters
desk located in the poster hall. Posters must be on display during the entire
congress, from Monday 3rd morning to Thusday 6th late afternoon.
Poster boards can be identified by the reference number that appears on the
panel and corresponds to the final number indicated in the Book of Poster
Abstracts. Your submission ID is not your poster ID. Due to data processing
some poster numbers might have changed with respect to the Congress
Homepage.
POSTER SESSIONS
|
Authors are kindly requested to stay close to their posters for discussion with
other participants as per the following schedule:
Poster Session II:
Tuesday 4th
16:00 – 19:00
16:00 – 17:00
even numbers
17:00 – 18:00
odd numbers
Poster Session II:
Wednesday 5th
16:00 – 19:00
16:00 – 17:00
odd numbers
17:00 – 18:00
even numbers
Posters must be removed on Thursday 6th at 19:00. Posters left on the panels
will not be mailed to the authors after the Congress. The Botanikertagung
2007 Hamburg will not be responsible for loss or damage occurring to
posters left on the panels.
BEST POSTER AWARD
|
The 5 best posters of the Congress will be choosen by the chairs. Selected
posters will be marked with a label on Wednesday 5th 18:00. Authors of
these posters are kindly requested to contact the staff at the registration
desk.
2
GENERAL INFORMATION
P01
P01: BIODIVERSITY IN
AFRICA
P01: 1
African Vegetable Diversity in the Limelight: Project
Activities by ProNIVA
Maass B.1, Keding G.2, Boniface K.3, Kasambula P.4,
Kumwenda R.5, Marandu W.6, Swai I.7 and Virchow D.8
1
Georg-August-Universität Göttingen, Germany; 2JustusLiebig-University, Giessen, Germany; 3Rwanda Institute of
Agriculture Research, Rwanda; 4Kawanda Agricultural
Research Institute, Uganda; 5Bvumbwe Agricultural
Research Station, Limbe, Malawi; 6Bioversity
International, at AVRDC-RCA, Arusha, Tanzania;
7
Horticultural Research Institute, Tengeru, Tanzania; 8The
World Vegetable Center, Reg. Center for Africa (RCA),
Arusha, Tanzania; [email protected]
Safeguarding
indigenous
vegetables
biodiversity,
improving their utilisation and, thereby, contributing to
reduce malnutrition and poverty among small-scale farmers
and consumers in four partner countries (Malawi, Rwanda,
Tanzania, Uganda) is one of ProNIVA’s main goals.
ProNIVA stands for “Promotion of Neglected Indigenous
Vegetable Crops for Nutritional Health in Eastern and
Southern Africa”, and was initiated in 2003 by The World
Vegetable Center’s Regional Center for Africa (AVRDCRCA) and partners. The utilisation, collection, production
and consumption of these vegetables is presently
decreasing in the region, leading to genetic erosion that
takes place at a rapid pace.
Important production and consumption issues of indigenous
vegetables perceived by farmers from different districts in
four countries have been studied by the ProNIVA project.
Survey data have been gathered by both individual
interviews and focus group meetings. Considerable
differences regarding vegetable diversity available as
mentioned by the interviewees were found among districts
and countries. Main factors perceived for these differences
were related to urbanisation, agro-ecological conditions,
cultural aspects and individual preferences.
Germplasm of the most important traditional vegetables in
the four partner countries was collected and, among others,
accessions of Amaranthus spp. (125), Cucurbita spp. (82),
Cleome gynandra (86), and Solanum spp. (African
eggplant; 67) have been gathered. Diversity research on
this vegetable germplasm is presently taking place.
P01: 2
Collecting, Assessing and Understanding Traditional
Vegetable Diversity: the Case of "Mlenda" in Tanzania
Keding G.1, Swai I.2 and Maass B.3
1
Insitute of Nutritional Sciences, Justus-Liebig-University
Giessen; 2The World Vegetable Center (AVRDC-RCA),
Arusha, Tanzania; 3Department of Crop Sciences, GeorgAugust-University Göttingen;
[email protected]
Information on wild traditional vegetables was collected
both in 2003 and 2006 in villages of different central
Tanzanian districts within the frame of the project
“Promotion of Neglected Indigenous Vegetable Crops for
Nutritional Health in Eastern and Southern Africa” led by
the World Vegetable Center (AVRDC-RCA) in Tanzania
and partners. During 2003, it was found that a vegetable
called "Mlenda" and identified as wild jute mallow
(Corchorus olitorius: Tiliaceae) was one of the most
important vegetables for farmers in two semi-arid districts.
The high diversity of jute mallow types consumed by
farmers and distinguished within a local classification
system was remarkable.
As the harvested vegetables appeared to resemble each
other strongly, it was only noticed later that what farmers
call "Mlenda" were different vegetable species from
Tiliaceae as well as Pedaliaceae. This was confirmed
during the survey in 2006. Subsequently, three different
species were identified to form "Mlenda" types, namely,
besides jute mallow, Ceratotheca sesamoides: Pedaliaceae
(false sesame) and Sesamum angustifolium: Pedaliaceae
(wild simsim).
More confusion is caused as the local term "Mlenda" is also
used for the mixture of okra and pumpkin leaves when
cooked together. Additionally, it can stand for cooked
leaves from the Baobab tree. While different local names
are often available for the same plant, in this case one local
name was given to several plants with similar qualities.
However, these vegetables still differ from each other in
nutritive value, taste, and time of availability.
P01: 3
Comparative studies of soil seed reserves in semi-arid
farm lands with special reference to the availability of
safe-sites – preliminary results
Dreber N.
University of Hamburg, BIOTA Southern Africa;
[email protected]
Rangeland degradation and related biodiversity loss is a
common problem in (semi-)arid ecosystems. Climatic
events (e.g. droughts) and inadequate grazing management
directly affect soil properties and vegetation cover, which
may result in a state of degradation. In arid areas, rainfall is
the main driving factor for the regeneration of vegetation,
whereas the soil seed reserves are a determining factor for
its capacity to respond to rain. Inadequate management
practices may reduce the size or even change composition
of the soil seed reserves. Heavy grazing, for instance, does
not only impact seed-bearing plants high in grazing value
by reducing numbers of flowers and fruits and thus
recruitment. It also affects soil stability due to increased
trampling thus decreasing the availability of safe-sites for
seed accumulation and seedling establishment.In southern
Namibia, the vegetation of communal farm land is often
degraded due to several decades of heavy grazing.
Understanding the condition of the soil seed reserves is
highly important for the assessment of the regeneration
potential of degraded habitats if the aim is to improve the
veld condition. Two neighbouring farms are compared
regarding the soil seed reserves of bare-patches and safesites, one under communal (heavily grazed) and one under
commercial (extensively grazed) tenure. In a preliminary
study, the suitability of the sampling-design, the sampling
effort and germination methods in the greenhouse were
evaluated. Results are presented and discussed with regard
to their significance for subsequent studies.
POSTER ABSTRACTS
3
P01
P01: 4
P01: 6
Genetic multiplicity and diversity in a tropical
multipurpose tree species, Cordia africana
(Boraginaceae) in Ethiopia
Derero A., Gailing O. and Finkeldey R.
Georg-August-University of Goettingen, Germany;
[email protected]
Germination of a myco-heterotrophic plant:
Afrothismia hydra (Burmanniaceae)
Imhof S.
Philipps-Universität, Germany; [email protected]
A total of 22 populations of the tropical multipurpose tree
species, Cordia africana Lam. (Boraginaceae) were
sampled from virtually all growing regions of the species in
Ethiopia to investigate its genetic variation. DNA was
isolated from dried leaves using the DNeasy Plant Kit
(Qiagen) and fingerprinted employing the molecular
technique Amplified Fragment Length Polymorphisms
(AFLPs). The analysis of the genetic multiplicity in terms
of percent polymorphic loci (PLP) and the Nei’s genetic
diversity revealed that the PLP varied from 62.2 % to
92.2%, and the diversity ranged from 0.220 to 0.320 among
the populations. The mean PLP and the mean diversity
within populations (Hw) was 85.7% and 0.29, respectively.
The analysis of molecular variance (AMOVA) revealed
significant differentiation (ΦST = 0.07, p < 0.001) among
the populations. The pairwise population comparisons
employing ΦST revealed significant differentiation (p <
0.01) between population pairs in the majority (88%) of the
cases. The Mantel test revealed a significant correlation (r =
0.35, p < 0.001) between the geographic and the genetic
distance matrices. However, the UPGMA dendrogram
constructed employing Nei’s genetic distance generally
revealed weak geographical structure. The results indicate
that populations of Cordia africana exhibit various levels
of genetic variation and carry genetic information that
resulted in their significant differentiation. We recommend
that conservation and improvement efforts of the species
should incorporate several populations over a wide
geographical range.
P01: 5
Genetic Variation of Triplochiton scleroxylon (K.
Schum) under different Regimes of Human Impact in
Nigeria
Akinnagbe A., Gailing O. and Finkeldey R.
Institute of Forest Genetics and Forest Tree Breeding,
Goettingen, Germany; [email protected]
Triplochiton scleroxylon is one of the most important
timber tree species in Nigeria. However due to human
activities, its populations have been highly fragmented and
disturbed. In the present study, the genetic diversity of the
tree under various human impacts in Akure Forest Reserve,
Nigeria was analysed. For this investigation, fresh leaf
samples of Triplochiton scleroxylon were collected from
farmland, logged plot, fragmented plot and an old
Permanent Sample Plot (PSP) where human inference has
been relatively very low. The genetic diversity was
assessed by Amplified Fragment Length Polymorphism
(AFLP) markers. Out of a total of 134 scorable bands, 113
were polymorphic (86%). The differences in the gene
diversity among the populations did not vary widely in
such a way to detect effects of human impact. However at P
< 0.01 level of significance, the most fragmented
population (farmland population) revealed the highest
linkage disequilibrium between AFLP fragments of 14.3%
followed by the logged population with 10.7%, fragmented
population with 7.7% and the PSP population with 6.8%.
This result possibly reflects the effects of genetic drift.
4
POSTER ABSTRACTS
The African genus Afrothismia (Burmanniaceae) comprises
ten species, seven of which were described only within the
last three years. Hence, very little is known on these tiny,
but extremely adapted myco-heterotrophic plants (MHP).
MHP lack chlorophyll and depend entirely on their
mycorrhizal fungi. The germination process of MHP other
than orchids and Monotropoideae has yet never been
depicted. This presentation provides the complete ontogeny
of Afrothismia hydra from seed to seed dispersal.
The up to 0.7 mm long, rice-shaped seeds germinate with
root tissue only, disrupting the seed coat and developing a
first ovoid root tubercle. At the proximal end of the
tubercle a second tubercle arise, and further root initials
indicate the sequential growth of more root tubercles.
When this root aggregate enlarges a central axis to which
all roots are connected becomes visible. This axis has a
growth pole where new root tubercles arise. The same
growth pole will later develop into a stem with scale leaves
finally terminating in a sympodial inflorescence. After
anthesis the corolla tube disintegrates, leaving a pyxidium
which opens by means of a peculiar elongating placenta,
here called ‘placentophore’. The placentophore elevates the
placenta with attached seeds above the flowering level and
is interpreted as an adaptation to ombrohydrochory.
The lack of hypocotyl, cotyledon and primary shoot during
germination is addressed and compared to the classical
germination concept of monocotyledons.
P01: 8
Large genera still harbour surprises: Cynanchum and
Calciphila (Apocynaceae - Asclepiadoideae)
Liede-Schumann S. and Meve U.
University of Bayreuth, Germany; [email protected]
Over several years, the large genus Cynanchum
(Apocynaceae - Asclepiadoideae: Asclepiadeae) has been
shaped from a dustbin genus to a well-circumscribed
monophyletic unit. Before the arrival of molecular
methods, Vincetoxicum could be clearly split from
Cynanchum using morphological and chemical characters.
Plastid markers have shown that all American groups
except one subsumed under Cynanchum belong into
several, unrelated subtribes of Asclepiadeae. With these
changes, the genus was considered monophyletic, albeit
composed of a number of poorly resolved larger clades.
One species, C. galgalense from Somalia, however, did not
join the Cynanchum clade, but was preliminary left in
Cynanchum for morphological reasons. During work for
the Flora of Somalia account of ApocynaceaeAsclepiadoideae, a new species of uncertain affinity was
discovered. Analysis of nrDNA and plastidDNA revealed
that the new species was most closely related to C.
galgalense and that the two species form a small genus,
Calciphila, of uncertain affinity and very narrow
distribution. This find once again demonstrates that the
Horn of Africa is a center of endemism for
Asclepiadoideae, where not only endemic species abound,
but even endemic genera, such as Goydera Liede and
White-Sloanea Chiov. Calciphila gillettii Liede & Meve, is
most closely related to the recently described Cynanchum
P01/P02/P03
galgalense Liede, which was only provisionally included in
Cynanchum L. after DNA analysis.
P01: 9
New insights into the phylogeny of the genus Lithops
N.E. Br. (Aizoaceae) based on Amplified Fragment
Length Polymorphism (AFLP)
Kellner A.1, Ritz C.2, Schlittenhardt P.3 and Hellwig F.2
1
Institut für Allgemeine Botanik, Justus-Liebig-Universität
Gießen, Germany; 2Institut für Spezielle Botanik,
Friedrich-Schiller-Universität Jena,Germany; 3Ispra, Italy;
[email protected]
The genus Lithops (Aizoaceae, Ruschioideae) is distributed
in the southern part of Africa and comprises about 40
species. The taxonomy of the genus is notoriously difficult
due to the reduction of many vegetative characters as
adaptation to desert habitats. But these few morphological
characters are extremely variable resulting in huge number
of species and subspecies being described. Previous studies
suggested a very recent origin of Lithops and the
Ruschioideae, because the level of sequence variation
within several chloroplast markers and the nuclear internal
transcribed spacers (ITS) was very low. In this study we
investigated the phylogeny of Lithops using the much more
variable Amplified Fragment Length Polymorphism
(AFLP). The phylogenetic reconstructions based on
Distance and Bayesian analyses revealed nine major clades
within Lithops, which were also supported by morphology
and biogeography. We also could demonstrate that many of
the described subspecies within Lithops do not represent
natural taxonomic units. Molecular data suggest multiple
convergent evolution for the colouration of the succulent
leaves, because it matches highly with the very
heterogeneous soil colours of the habitats and thus may
function as an adaptation against grazing animals. As in
many other taxa of the Cap flora the presumably recent
radiation of the genus was not only driven by allopatric
speciation but also facilitated by parapatric speciation due
to the extreme habitat heterogeneity.
P01: 10
Poster: Nectaries in Aizoaceae: The case of
Glottiphyllum N.E.Br.
Niesler I. and Hartmann H.
Biozentrum Klein Flottbek, Germany; [email protected]
In SEM investigations in various members of the family
Aizoaceae, it was possible to demonstrate the presence of
nectar slits over nectar glands in strict correlation; nectaries
are therefore mesophyllous, glands lack any intercellular
spaces and exudation of nectar occurs through the slits.
Based on these results, a revised classification of nectaries
for Aizoaceae is offered, and the presence of nectaries in
the genus Glottiphyllum can be shown.
P01: 11
The High Atlas as Centre of Diversity of Thorny
Cushion Shrubs: Mechanisms of Species Coexistence
Finckh M. and Augustin A.
BIOTA Maroc, Germany; [email protected]
With more than ten species of thorny cushion shrubs, the
High Atlas region can be regarded as the centre of diversity
of this life form in the western Mediterranean. Sympatric
cushion shrubs seem to be differentiated by their
architecture and geometry, with rather flat cushions
characterising pioneer species and round cushions often
formed by those regenerating in the protection of other
plants before overgrowing them.
Another trait differentiating the cushion shrub species is
their seed development and protection. While species such
as Alyssum spinosum L. and Bupleurum spinosum Gouan
develop inflorescence spines, leaving its actual flowers and
seed unprotected, the flowers and seed of Erinacea
anthyllis Link, Vella mairei Humbert and Cytisus purgans
(L.) Boiss. lie below the spiny surface of the cushion. The
divergent susceptibility to infestation with parasitic
Cuscuta triumvirati Lange may also play an important role
for long time establishment in the oromediterranean belt.
Niche segregation in terms of regeneration and prevention
of herbivory facilitates the diversity of seemingly similar
thorny cushion shrubs.
P02: BIOTECHNOLOGY
AND SOCIETY
P02: 1
Poster presentation: Microalgal Biotechnology Production of Chlorella in closed photobioreactors
Ullmann J., Ecke M. and Steinberg K.
Bioprodukte Prof. Steinberg Produktions- und Vertriebs
GmbH & Co. KG, Germany; [email protected]
The largest production plant for microalgae based on
photobioreactor
(PBR)technology is
located
in
Klötze/Germany and was built in 1999. The plant consists
of 20 PBR`s with a total volume of about 600.000 liter of
culture solution. The solution is pumped through a 500 km
closed glass tube system and algae are harvested by
centrifugation and spray-drying. Several microalgae species
are considered to be suitable for the production in such
PBR`s. The company "Bioprodukte Prof. Steinberg" mainly
produces Chlorella vulgaris. The biomass is used for the
production of supplementary food and as raw material for
the food and cosmetic industry.
Our research is focused on the further development of the
PBR technology, the optimization of the culture methods
and parameters for Chlorella and other promising algae
species and the development of innovative products.
P03: CELL - TREE TIMBER
P03: 1
History and characterization of an arboreal and shrub
community of a Seasonal Semideciduos secondary
Forest fragment in Ribeirão Preto,State of São
Paulo,Brazil
Esteves S., Marques E., Tanaka G. and Pereira R.
Departamento de Biologia, FFCLRP , Universidade de Sao
Paulo, Brazil; [email protected]
The fragment is located in Ribeirão Preto City, State of São
Paulo, Brazil, in the campus of the Universidade de São
Paulo - USP (47°51’01.66’’W). It is 2,6 ha. of Seasonal
Semideciduos secondary Forest from the Atlantic Forest
biome. This area was once a place for the coffee grain
drying, in one of the most important brazilian coffee farms
POSTER ABSTRACTS
5
P03
between 1870 and 1940. Later it had other utilities until its
abandonment that happened about 40 years ago. At this
time a natural regeneration process was initiated. For the
community characterization, 35 plots of 20m x 20m were
established and all individuals with PBH (perimeter at
breast height) ≥ 15 cm, alive or standing deads, were
identified and measured. The phytosociologic parameters
of density, dominance and frequency (absolute and relative)
were calculated for the community. The results were
compared to others fragments of the region. 1856
individuals were sampled (67 morphospecies, 52 genus and
28 families). The families with greater number of species
were Leguminosae (16), Euphorbiaceae (5), Bignoniaceae,
Moraceae, Myrtaceae (4 each) and Meliaceae (3). The
number of exotic species is high and corresponds to about
20% of the total. The results show that the forest fisionomy
recovered in this ~40 years period. However, the vegetal
community structure is different from that found in more
preserved areas.
P03: 2
EFFECTS OF UV RADIATION ON THE
SUCCESSION OF BENTHIC COMMUNITIES IN
SPITSBERGEN
Fricke A.1, Molis M.2, Wiencke C.1, Valdivia N.2 and
Chapman A.3
1
Alfred Wegener Institute, Bremerhaven, Germany;
2
Biological Station Helgoland, AWI, Helgoland, Germany;
3
Dalhousie University, Biology Department, Halifax,
Canada; [email protected]
At present there is very little information how
macrobenthic communities are affected by UV radiation. In
particular, it is not clear whether the damaging effects of
UV radiation can be buffered by ecological processes. In
the present study, a field experiment in the intertidal of the
Arctic Kongsfjorden (78°55’N, 11°56’E) in Spitsbergen
was conducted from 12 May to 10 July 2006, and the
individual and interactive effects of UV-radiation and
successional age of macrobenthic communities, developed
over different time periods in the sublittoral, were
investigated. Communities were transplanted from their
original place at 8 m water depth onto floating
constructions in 0.5 m water depth and exposed for a period
of 4 and 8 weeks to different light treatments: PAR (400700nm), PAR+UVA (320-700nm), PAR+UVA+UVB
(280-700nm) and full sunlight (control). Macrobenthic
species composition, biodiversity, percentage cover and
biomass (dry mass) were analyzed. Additionally, the light
regime in the atmosphere and at 50cm water depth was
monitored constantly. The results show that increased solar
radiation after transfer from deep to shallow water, as well
as UV radiation, affected the succession of macrobenthic
communities. The differential spectral ranges tested
showed negative as well as positive effects. Observed
differences between the communities can be explained by
the different UV tolerances and the interactions between
the different species. In conclusion, older communities
seemed to be more stable in their composition than younger
ones.
P03: 3
Faster evaluation of induced floral sterility in
transgenic early flowering poplar
Hönicka H. and Fladung M.
BFH, Institute for Forest Genetics and Forest Tree
Breeding, Germany; [email protected]
A major concern over the use of transgenic trees is the
potential for extensive transgene dispersal through pollen
and seeds. The incorporation of sterility genes into
transgenic lines of trees has been proposed to reduce or
even avoid gene flow of transgenes into non-transgenic
relatives, which is one of the main ecological concerns with
respect to commercial use of transgenic plants. The
evaluation of strategies for the induction of sterility in
transgenic forest tree species has been hindered by their
long vegetative periods. In this study early flowering
35S::Leafy poplar lines were used for the evaluation of two
different sterility constructs, TA29::Barnase and CGPDHC::Vst1. The combination of two transgenic
approaches, one to induce early flowering and a second for
the induction of sterility, allowed evaluation of both
sterility strategies two years after transformation. This is a
very short period of time considering the long vegetative
period of up to ten to twenty years common in forest tree
species. This approach opens new opportunities for the
assessment of mechanisms for this plant group.
P03: 4
Heterologous overexpression of BpMADS4, a
FRUITFULL-like MADS box gene from birch, induces
a delay on leaf senescence and dormancy in transgenic
aspen
Hoenicka H.1, Hanelt D.2 and Fladung M.1
1
BFH, Institute for Forest Genetics and Forest Tree
Breeding, Germany; 2University of Hamburg, Germany;
[email protected]
MADS box genes have been shown to be important to
flower and vegetative tissue development, senescence and
winter dormancy. The constitutive expression of the
BpMADS4 gene from birch induces a delay on leaf
senescence and dormancy in transgenic poplar. Different
analysis revealed that 35S::BpMADS4 poplars maintained
photosynthetic activity, chlorophyll and proteins in leaves
under winter conditions. BpMADS4 may be influencing
transcription factors regulating the senescence and
dormancy process due to homology with homeobox
proteins of poplar related to both traits. Little is known of
the regulatory genes that co-ordinate senescence,
dormancy,
chlorophyll/protein
degradation,
and
photosynthesis at the molecular level. Dissecting the
molecular characteristics of senescence regulation will
probably involve the understanding of multiple and novel
regulatory pathways. The results presented here may be
useful for achieving this aim in poplar.
P03: 5
Sucrose cleaving enzymes in the wood of Robinia
pseudoacacia during the infection with pathogenic fungi
Magel E., Busch H., Fischer I. and Moreth U.
Wood Biology, Department of Wood Science, University
of Hamburg, Germany; [email protected]
In trees, injured and infected woody tissue is isolated by
compartmentalization. Adjacent to the infection site,
6
POSTER ABSTRACTS
P03
discoloured reaction zones are formed by living
parenchyma cells in order to establish chemical barriers
against invading microorganisms.
In Robinia pseudoacacia L., our model tree, flavonoids are
accumulated during the formation of discoloured reaction
zones. Cell death in the transition zones between
discoloured and non-coloured tissues is characterized by
high metabolic activity as shown by the synthesis of
phenols, and should therefore create a strong sink for
carbohydrates. Sink specific enzymes such as invertases
and sucrose synthase supply energy and precursors for
secondary metabolism via different pathways. The purpose
of this study was to investigate the modification of
sucrolytic competence characteristic for wood discoloration
during compartmentalization of damage in standing trunks
of Robinia pseudoacacia. After identification of genes
coding for sucrose synthase, neutral, acid and cell wall
bound invertases in wood of black locust, expression
studies of these genes were performed in the discolouring
tissues. Our data show that sucrose synthase and invertases
are involved in this discolouration processes. With respect
to invertases, tissue-specific and developmental-specific
differences were found.
P03: 6
Climate change and the effects of increased air
temperature on conifer cold hardiness
Ensminger I.1,2, Busch F.2, Caron S.3, Tarca A.4,
MacKay J.3 and Hüner N.2
1
Universität Freiburg, Germany; 2University of Western
Ontario, ON, Canada; 3Université Laval, QE, Canada;
4
Wayne State University, MI, USA;
[email protected]
Climate change will affect the functioning and productivity
of temperate and boreal trees and forest ecosystems. We
studied the regulation of photosynthesis and carbon
metabolism in the evergreen conifer Pinus banksiana (Jack
pine) in response to climate change scenarios. In a series of
experiments we manipulated daylength and growth
temperature during autumn growth conditions in order to
disseminate the significance of each factor as
environmental signal as well as their interactive effects on
carbon uptake, structure and composition of the thylakoid
membrane and changes in energy partitioning. Large-scale
gene expression analysis further revealed an interactive
effect of the autumn photoperiod and low temperature
resulting in the enrichment of specific biological themes
(GO categories). The enriched biological themes are
distinct or have only little overlap with the enriched themes
observed in conifer trees exposed to either autumn
photoperiod or low autumn air temperature alone.
Furthermore, both, physiological and gene expression data
suggest that increased autumn air temperature combined
with autumn photoperiod (and thus representing an
increased length of the growing season under climate
change scenarios) might not help to increase the carbon
gain in Jack pine under these conditions.
P03: 7
Drought stress reaction of European aspen (Populus
tremula L.) – a QTL-mapping approach
Meyer M.1, Rust S.1, Krabel D.1, Helle G.2, Günther B.3,
Markussen T.4 and Fladung M.4
1
Technische Universität Dresden, Forest Botany, Tharandt,
Germany; 2Forschungszentrum Jülich GmbH, ICG-V,
Jülich, Germany; 3Technische Universität Dresden, Forest
Utilisation, Tharandt, Germany; 4BFH, Inst. for Forest
Genetics and Forest Tree Breeding, Hamburg, Germany;
[email protected]
Elevated aridity and scarcity of water are likely
consequences of global warming in Central European
ecosystems and will cause more negative minimum
seasonal water potentials (-Ψmin). -Ψmin exerts selective
pressure on trees. Poplar varieties well adapted to more
negative -Ψmin are badly needed for short rotation coppicing
as well as for forestry in pioneer ecosystems. Our QTLmapping study (quantitative trait loci) provides DNAmarkers linked to water use efficiency and resistance to air
embolism of Populus tremula L. Genetic linkage maps
were constructed harbouring SSR and AFLP markers
(software package JoinMap®). The average maternal
recombination distance was reduced resulting in an
approximately 19 % longer map for the female tree which
was consistent with results from other aspen mapping
projects. The maps were used for mapping of relevant
quantitative traits (QTs), e.g. vessel length/diameter/cross
section ratio, fibre length, wood density, signatures of
stable isotopes (δ13C, δ18O) and radial increment. The QTs
were measured separately for the growth rings of the sevenyears-old mapping population showing a juvenilety effect
on the physiological data. The ratio of the values of the
respective trait in a drought and a non drought year
(2003/2002) was used for QTL-mapping of drought
reaction. At present, the maps are being enriched with
additional SSR markers available from the International
Populus Genome Consortium to allow comparative
mapping with other poplar species and the transfer of
candidate gene information to the aspen linkage maps.
P03: 8
European beech provenances under climate change:
response of transpiration, chlorophyll fluorescence and
tree ring growth
Beck W., Kriebitzsch W., Schmitt U. and Veste M.
Federal Research Centre for Forestry and Forest Products,
Hamburg, Germany; [email protected]
The ongoing climate change will increase temperature by
1.5-2.5 K. As a consequence, precipitation will decrease
and the increased frequency and severity of drought will
affecting the growth of plants by water depletion in
northern and eastern Germany. Already in the recent years
drought periods affected the ecosystems in Western
Europe. Furthermore, increasing temperature causes a shift
of the zones of natural forest vegetation types as well as of
the range of the beech (Fagus sylvatica) towards higher
altitudes and to the north and – perhaps - northeast. Various
ecotypes have developed in Europe under different local
climate and soil conditions based on genetically
differences. A provenance trial was established in
Schädtbeck (Schleswig-Holstein) to compare the
adaptability of beech provenances to climate changes. For
the investigations 6 provenances from Austria, Czech
Republic, Germany (Brandenburg, Harz), Romania and,
Spain were selected representing a with range of climatic
conditions from 575 mm to 1400 mm annual rainfall.
Transpiration, leaf conductance and electron transport rates
were determined during the summer in July 2006. Samples
for tree ring growth were sampled covering the growth
period between 1996 – 2006. The summer drought in 2003
had drastic effects on the tree growth in all provenances,
while the recovery depends from the provenances.
POSTER ABSTRACTS
7
P03
P03: 9
Herkunfts-Identifikation von forstlichem
Vermehrungsgut
Markussen T., Fladung M. and Degen B.
Bundesforschungsanstalt für Forst und Holzwirtschaft Institut für Forstge; [email protected]
Der überwiegende Teil des forstlichen Vermehrungsgutes
für künstliche Verjüngungen von Waldbeständen soll
gemäß dem Forstvermehrungsgutgesetz (FoVG) aus
gesetzlich zugelassenen Erntebeständen stammen. Ziel ist,
durch geeignete Wahl des Vermehrungsgutes einen Beitrag
zu
leisten,
dass
aus
kostenintensiven
Bestandesbegründungen
angepasste,
leistungsfähige,
hochwertige und stabile Baumbestände hervorgehen.
Bisher wird die Herkunft von forstlichem Vermehrungsgut
fast ausschließlich schriftlich dokumentiert. Die amtlichen
Kontrollmechanismen sind allerdings unzureichend, um
Waldbesitzern ausreichende Sicherheit bezüglich der
Herkunft
von
forstlichem
Vermehrungsgut
zu
gewährleisten. Durch Öffnung des europäischen Marktes
mit seinem zum Teil komplizierten Kontrollsystemen
kommt erschwerend hinzu, Saat- und Pflanzgut
unbekannter oder zweifelhafter Herkunft vom deutschen
Markt fernzuhalten. Hieraus resultierend formuliert sich im
Sinne des Verbraucherschutzes somit ein dringender
Handlungsbedarf.
Da eine wissenschaftlich fundierte Kontrollmöglichkeit zur
Herkunftsdefinition von Vermehrungsgut bisher nicht
existierte, wurde im Rahmen einer Pilotstudie in
Zusammenarbeit mit der Forstgenbank NRW der Aufbau
eines Herkunfts-Identifikations-Systems (HIS) mit Hilfe
von hochvariablen DNA-Markern erprobt, deren
Ergebnisse in Form eines Posterbeitrages präsentiert und
diskutiert werden sollen.
P03: 10
Molecular basis of discoloration processes in broadleaved trees – Gene expression analyses of key enzymes
of flavonoid biosynthesis in Robinia pseudoacacia L.
Lange H. and Magel E.
Universität Hamburg, Germany; [email protected]
Discolorations in the wood of trees occur as constitutive
heartwood formation or as defence reactions to pathogens.
These processes are characterized by flavonoid
biosynthesis, in which phenylalanine ammonia lyase (PAL)
und chalcone synthase (CHS) play a key role. Both
enzymes are encoded by multigene families.
Aim of the present work is to investigate differential
expression patterns of PAL and CHS genes related to
discolorations within the wood of R. pseudoacacia L. Up to
now several PAL and CHS genes were sequenced. For each
gene, gene specific primers were designed and were used
for expression analyses by semiquantitave PCR.
First results indicate that both PAL and CHS gene family
members are differentially expressed in the wood of R.
pseudoacacia L. trunks dependent on tissue type and
season.
PAL genes are up-regulated in the sapwood-heartwood
transition zone (TZ) as well as in the differentiating xylem
(DX). Differences in the degree of expression were
detected between the different PAL genes.
CHS was exclusively expressed in the TZ. Different family
members revealed differences in their expression levels
with highest expression during autumn.
8
POSTER ABSTRACTS
Strong expressions of PAL genes indicate an involvement
in two different metabolic pathways: (1) flavonoid
synthesis in TZ (2) lignin synthesis in the DX.
CHS expression in the TZ points out its role for flavonoid
biosynthesis.
P03: 11
Seed germination in two dominant treeline species
Betula litwinowii and Rhododendron caucasicum in the
Central Caucasus
Akhalkatsi M.1, Smith W.2, Abdaladze O.1 and
Nakhutsrishvili G.1
1
Niko Ketskhoveli Institute of Botany & Ilia Chavchavadze
State University, Georgia; 2Wake Forest University,
Winston Salem, NC, USA; [email protected]
In the Central Greater Caucasus Mountains, Georgia,
Betula litwinowii occurs on north-facing slopes, forms the
alpine timberline, and reaches its treeline limit only when
associated with the broadleaf evergreen shrub,
Rhododendron caucasicum. We studied seed germination
requirements to temperature and light in both species. The
germination tests at different light conditions have shown
that no germination has occurred in R. caucasicum in the
dark. B. litwinowii was germinated in both treatments. Seed
imbibition was prolonged in R. caucasicum (3 weeks), but
germination and cotyledon formation were happened very
rapidly (2 days). Seeds of B. litwinowii were already
imbibed after 48 h and were germinated after 4 days.
Although, cotyledon formation and seedling growth
requires approximately 2 weeks. Radicle of the birch
develops root hairs soon after emergence and is very
sensitive to drying. Seedlings isolated from Petri dish dry
up already after 3 min. Radicles of R. caucasicum have no
root hairs until first leaf develops and seedlings are more
resistant to drying. They remain viable several hours in dry
condition. We suppose that seed germination requirements
of studied species determine their distribution patter in
natural environment. R. caucasicum grows in better
illuminated habitats under open subalpine krummholz and
above treeline. But, it does not enter birch forest with
closed canopy at lower elevations. Shaded and moist
microhabitat under Rhododendron shrubs may facilitate
successful establishment of birch seedlings at the alpine
treeline.
P03: 12
Somatic embryogenisis in Nordmann fir (Abies
nordmanniana) and its potential application for clonal
mass propagation
Zoglauer K.1, Aurich C.1, Richter M.2 and Zäpernick
M.2
1
Humboldt University Berlin, Germany; 2Horticultural
Centre Münster-Wolbeck; [email protected]
Nordmann fir has an enormous commercial importance for
Christmas tree production in Europe. It is exclusively
grown from seeds harvested form natural population in the
Caucasian mountains. Clonal varieties would help to
improve the quality of trees and the cultivation
characteristics considerably. Methods based on somatic
embryogenesis are expected to become a realistic
possibility to solve these problems in the future. Recent
achievements in somatic embryogenesis of Abies species
will be presented including developmental patterns in
P04
comparison with zygotic embryogenesis as well as control
of embryo maturation, germination and acclimatization.
Acclimatization experiments with tens of thousands of
somatic seedlings in the last year indicate that large scale
clonal propagation of A. nordmanniana is now possible.
Achievements and problems in scaling up will be
discussed.
P04: DEVELOPMENTAL
BIOLOGY
P04: 1
A novel cluster of polyketide biosynthesis genes is
involved in sexual development in the filamentous fungi
Sordaria macrospora and Neurospora crassa
Nowrousian M. and Kück U.
Lehrstuhl für Allgemeine und Molekulare Botanik, RuhrUniversität Bochum; [email protected]
During fungal fruiting body development, vegetative
hyphae aggregate to form complex multicellular structures.
Within the mature fruiting body, the sexual spores are
formed. Using microarray analysis, we have identified a
cluster of genes that are strongly upregulated during sexual
development in the filamentous ascomycete Sordaria
macrospora. Further analysis by quantitative real time PCR
showed that the genes from the orthologous cluster in
Neurospora crassa are upregulated during development,
too. The genes occupy a region of ~50 kb in the genomes of
both fungi and encode enzymes that are predicted to
participate in polyketide biosynthesis, including a putative
polyketide synthase. However, there are no characterized
orthologs from other organisms, thus, the product of the
putative biosynthetic pathway remains to be elucidated.
Analysis of a N. crassa knockout strain of one of the
predicted dehydrogenase genes of the cluster demonstrated
that this gene is involved fruiting body formation as the
mutant produces much fewer fruiting bodies than the wild
type.
P04: 2
An RNA-binding protein, Nab1, is specifically expressed
in reproductive cells of Volvox carteri
Kianianmomeni A., Nematollahi G. and Hallmann A.
University of Bielefeld, Germany;
[email protected]
Volvox carteri is a ~2000-celled multicellular eukaryotic
green alga with only two cell types: small somatic and large
reproductive. In a reproductive cell a single, big chloroplast
allows for a high photosynthesis capacity, which is required
before and during the subsequent cleavage divisions. By
contrast, the flagellated somatic cells own just a relatively
small chloroplast; somatic cells are specialized for motility
and phototaxis. Nab1 is an RNA-binding protein that was
identified through its ortholog in Chlamydomonas. Nab1 is
involved in regulation of photosynthesis, probably by
binding to LHCBM mRNA. Based on sequence data, a
LHCMB gene family with 12 members was identified,
which encodes the major HCLII polypeptides in Volvox.
The nab1 gene from Volvox is a nuclear, single copy gene.
It consists of six exons and five introns. The deduced Nab1
polypeptide is 242 amino acids in length. Quantitative
analysis of nab1 mRNA expression showed that nab1 is
expressed predominantly in reproductive cells. Nab1 is
known to contain two predicted nucleic acid binding
domains: a cold-shock domain (CSD) and an RNA
recognition motif (RRM). Genome data analysis indicated
that Nab1 is the only protein in Volvox with a CSD domain
and only a single protein with RRM motifs was identified
along with Nab1. The existence of CSD and RPM domains
in Nab1 from Volvox and Chlamydomonas suggest that
they are of utmost importance for RNA binding of Nab1.
The existence of an RNA binding consensus sequence in
Lhcbm genes of Volvox supports binding of Nab1 to
LHCBM mRNAs.
P04: 3
Analysis of root responses to salt stress in rice (Oryza
sativa)
Hwang I.1, Lee Y.1, Oh Y.1, Kim Y.1, Nam M.2, Yoon I.3
and Park* W.1
1
BK21 Graduate Program for RNA Biology, Department of
Molecular Biology, Institute of Nanosensor and
Biotechnology, Dankook University, Korea, South
(Republic of); 2Seoul Branch, Korea Basic Science
Institute,; 3Cell and Genetics Division, NIAB, Suwon 441707, Korea; [email protected]
Rice is one of the most important crops in the tropic and
subtropics. The performance of root function is supposed to
be important for the productivity of rice. Rice roots respond
to salinity and stop growth at higher than 100 mM NaCl.
Although natural soil environments containing such a high
concentration of salt is uncommon, they have experienced
problems caused by salt stress on the newly developed rice
fields on seaside. In an effort to overcome the salt
problems, we studied early responses of rice and maize
roots when they were suddenly exposed to high
concentrations of salts. For the purpose, we established a
digital image-recording system that is optimized for tracing
the changes of root shape in rice and maize. By applying
this imaging system, we magnified real-time images and
made time-lapse records of young roots responding to a
given salt stimulus, e.g., 100 mM NaCl. We are converting
the diverse real-time images obtained under a salt stress to
analyzed data, which can be used to determine the exact
location of the sensitive tissues and quantify the degree of
the salt responses. These basic data will be utilized for the
following molecular biological and biochemical works to
overcome the salt stress in the root systems of monocot
crop plants. [This study was carried out with the support of
"On-Site Cooperative Agriculture Research Project (Project
No. 106066-03-1-HD110)", RDA, Republic of Korea.]
P04: 4
Carpel Development, Transcription factors and gene
regulation by means of promoter evolution
Lange M. and Becker A.
University of Bremen, Germany; [email protected]
The female reproductive organs of angiosperm flowers, the
carpels, have undergone enormous morphological
diversification in their more than 125 million years of
evolution. We are interested in the genetically based
developmental processes which are to a large extent
controlled by transcription factors (TF) of diverse families.
While functional characters of TF coding sequences are
highly conserved between angiosperm species, the domain
of gene expression is exceedingly variable. We are
therefore investigating cis-regulatory sequences of carpel
development controlling TF in our basal eudicot
Ranunculales model plant California poppy (Eschscholzia
POSTER ABSTRACTS
9
P04
californica). To obtain promoter sequences, a BAC library
with poppy genomic DNA has been constructed. The
protocols for chromosome sized DNA isolation, size
selection via Pulse Field Gel Electrophoresis (PFGE), and
library construction have been intensively optimised.
Phylogenetic footprinting will be applied to compare
homologous TF promoter sequences of diverse plant
species. Additionally we treated seeds with Fast Neutron
Irradiation to establish a range of mutant plants in the
California poppy. This leads to deletions of variable size
and the mutated plants are crossed to create mutant sibling
lines. The results of structural and functional promoter
analyses along with the mutant characterization will be
integrated to better understand the complex interplay
between regulatory and coding sequences in shaping the
evolution of flower morphology.
P04: 5
Characterization of carpel developmental genes in
Eschscholzia californica
Orashakova S. and Becker A.
All flowering plants have male reproductive organs, the
stamens and female reproductive organs, the carpels. Much
about the carpel development genes is known in the model
eudicot plant Arabidopsis thaliana but much lesser in
other, evolutionary more interesting species. Eschscholzia
californica is a basal eudicot model species, belonging to
the Papaveraceae. There are many known regulators of
carpel development in Arabidopsis, which belong to
different families of transcription factors. We are interested
in the characterization of some putative ortholog carpel
genes in poppy. It is important to uncover the responsible
genes involved in carpel formation, how they function and
interact with each other.We are localizing the expression of
EcCRC, an ortholog of the Arabidopsis CRABS CLAW and
Oryza sativa DROOPING LEAF gene, and of EcSPT- the
ortholog of the Arabidopsis gene SPATULA in different
tissues by using in situ hybridisation and RT-PCR. Another
interesting carpel gene in Arabidopsis is AGAMOUS (AG).
Two homologs of the Arabidopsis AG genes in poppy have
been isolated- EScaAG1 and EScaAG2 but their function is
still unknown.For functional characterization of poppy
carpel genes I generate transgenic (gain-of-function)
Arabidopsis plants, overexpessing the corresponding
homologues from poppy. Furthermore, Arabidopsis spt, crc
and ag mutants will be complemented with the EcCRC,
EcSPT, ESacAG1 and EScaAG2 coding sequences. The
obtained phenotypes will highlight the conserved functions
between orthologous genes.
P04: 6
Characterization of the non-specific lipid transfer
protein (nsLTP) from apple scab susceptible and
resistant Malus domestica cultivars
Koutb M.1 and Gau A.2
1
Assuit university, Egypt; 2Hannover university, Germany;
[email protected]
In the case of apple scab in apple (Malus domestica) caused
by Venturia inaequalis, it has been demonstrated that the
level of nsLTP has declined in the apoplast by infection
with V. inaequalis. This finding indicates that nsLTP is
implicated in the infection. However the exact role of
nsLTP in this scenario is still unclear. Monitoring the
transcript level of nsltp revealed that the transcript in the
susceptible cultivar Elstar has declined by infection within
10
POSTER ABSTRACTS
one day. The cDNA of nsltp from Elstar and resistant
cultivar Remo was amplified by RT-PCR, cloned and
sequenced. Particle bombardment and transient expression
of nsLTP in fusion with GFP showed that nsLTP localized
mainly in the outer membrane of the chloroplast under light
conditions. A predicted phosphorylation site of nsLTP was
confirmed by immunoblot. The upstream region of nsltp
from both cultivars was amplified and used for promoter
activity using particle bombardment and DsRed. Results
revealed that the upstream region could drive the
expression machinery for the DsRed only under light
conditions. These results confirmed the close relation
between the presence of the predicted light responsive
elements and chloroplast localization on one hand and the
light dependence of promoter activity on the other hand.
DNA methylation analysis with methylation sensitive
restriction enzymes and southern blot revealed that cytosine
methylation in the upstream region and the structural nsltp
plays a pivotal role in the regulation process. Based on our
observations the biological function/s of apple nsLTP will
be discussed.
P04: 7
Comparative analysis of fruit dehiscence / indehiscence
in Brassicaceae
Mummenhoff K.1, Mühlhausen A.1, Polster A.1, Lobbes
D.2 and Theißen G.2
1
Spezielle Botanik, FB Biologie, Universität Osnabrück,
Deutschland; 2Genetik, Friedrich Schiller Universität Jena,
Deutschland; [email protected]
Studies in Arabidopsis suggest an idea of the anatomy and
the regulating network underlying the dehiscence (opening)
of fruits. To evaluate a general pattern of fruit opening we
have examined fruit anatomy and lignification patterns of
wild Brassicaceae species. We identified a suitable study
system consisting of Lepidium campestre (dehiscent fruits)
and L. appelianum (indehiscent fruits).
Fruit dehiscence in Arabidopsis is initiated by
differentiation of three specialized cell types in the fruit
valves, i.e., the lignified endocarp layer b, the lignified
valve margin cells, and the dehiscence zones. In Lepidium
campestre fruits, well developed dehiscence zones are
apparent and lignified valve margin cells and endocarp
layer b cells are discernible, whereas no valve margin cells
and no dehiscence zones are formed in L. appelianum
indehiscent fruits. These anatomical patterns clearly
correspond to Arabidopsis wild-type and indehiscent
mutants fruits, respectively. Current studies in Lepidium
concentrate on the identification and expression of
orthologous genes which control fruit opening in
Arabidopsis. The relative simple genetic mechanism by
which the mutant Arabidopsis indehiscent fruits originated
from typical wild-type dehiscent fruits, might easily explain
the rapid and independent evolution of indehiscent fruits in
different Brassicaceae lineages. Our project contributes to
the exploration of the developmental-genetic basics of
rapid and drastic morphological character change.
P04: 8
Control of Arabidopsis root hair growth by
phosphatidylinositol-4-phosphate 5-kinase
Stenzel I., Ischebeck T., König S. and Heilmann I.
Georg-August-University Göttingen, Germany;
[email protected]
PI4P
5-kinases
phosphatidylinositol
catalyze
the
production
of
4,5-bisphosphate (PtdIns(4,5)P2),
P04
which is a central regulator of metabolic processes and
signaling. PtdIns(4,5)P2 can interact with different target
proteins in different locations of the cell, affecting ionchannel activity, cytoskeletal dynamics, vesicle trafficking
and fusion, and is also a precursor for second messenger
production. The Arabidopsis genome contains eleven
putative PI4P 5-kinase genes, however, to date only
isoforms 1 and 10 have been functionally characterized in
vitro. The previously uncharacterized Arabidopsis PI4P 5kinase isoform 3 is expressed exclusively in root epidermal
cells and in root hairs. Activity and substrate specificity of
the recombinant enzyme as a PI4P 5-kinase was verified by
in vitro lipid phosphorylation assays. Independent T-DNA
insertions in the gene locus encoding AtPI4P 5-kinase 3
resulted in the near absence of PI4P 5-kinase 3 transcript
and in strongly reduced root hair formation. Root hair
growth was established in homozygous mutants by ectopic
expression of a cDNA clone of the wild type allele.
Truncated versions of the wild-type allele encoding active
proteins lacking an N-terminal MORN-repeat domain
cannot functionally complement disruption of the AtPI4P
5-kinase 3 locus. In vitro studies on recombinant MORNrepeat domains indicate the peptides selectively bind
phosphatidylinositolmonophosphates. A model is presented
for the role of AtPI4P 5-kinase 3 and its MORN-domain in
PtdIns(4,5)P2 formation required for root hair elongation.
P04: 9
Heterosis in early development of maize
Meyer S. and Scholten S.
University Hamburg, Germany; [email protected]
Heterosis is the superior performance of hybrids compared
to their parental inbred lines and take shape early after
crossbreeding. We found clear heterotic traits in embryos
and less pronounced effects in endosperm six day after
pollination in different maize inbred line combinations. To
identify differentially expressed genes in this early
developmental stage we generated cDNA populations
enriched for differential expressed genes between hybrids
and the corresponding inbred lines by supression
substractive hybridization. By differential screening of
these cDNAs and quantitative RT-PCR analysis we
identified various genes and expression pattern between
hybrids and inbred parents which might be associated with
heterosis. To further analyze gene expression pattern in
early kernel development we constructed a glass
microarray with subtracted cDNAs, a cDNA collection of
chromatin modifying genes (www.chromdb.org) and
cDNAs representing active genes or stored transcripts of
female gametes as probes. Targets were generated using
microdissected embryos and endosperm six days after
pollination separately to account for the different genomic
rations of these two tissues. Both inbred genotypes and
both reciprocal hybrids of highly heterotic dent/flint and
dent/dent combinations were compared. Based on these
expression profiles we selected genes for more detailed
functional analyses. Together these data will serve as entry
points to explore gene regulatory networks involved in
early characteristics of heterosis.
P04: 10
Loss of the nuclear Gene for a Chloroplast
Transcription Factor severely affects the phenotype but
is counterbalanced by a Rescue Mechanism during
Development
Schweer J., Loschelder H. and Link G.
Department of Biology, Germany; [email protected]
Chloroplasts contain two RNA polymerases: the nucleusencoded phage-type enzyme, NEP, and the plastid-encoded
bacterial-type enzyme, PEP. As in E. coli, the transient
interaction between a sigma factor and the PEP core
polymerase resulting in the assembly of the holoenzyme is
required for efficient and specific transcription. In A.
thaliana, six nucleus-encoded sigma factors have been
identified and studied with the aim of defining their roles in
promoter-, development- and environment-specific
transcription (Schweer et al., 2006). To adress these
questions, sigma knockout plants have become invaluable
tools.
In the presented work, we have compared RNA expression
levels of plastid genes in wildtype and SIG6 knockout lines
at various developmental stages. Results that provide new
mechanistic insights were obtained for a DNA region
spanning the operons atpB/E and ndhC-J: In the mutant we
observed the loss of certain chloroplast transcripts and,
conversely, the appearance of new RNA species not seen in
wildtype. The latter (mutant-specific) transcripts seem to be
initiated from far-upstream regions of atpB and other
chloroplast genes. These regions reveal clustered sequence
elements known to be used by NEP. Our results are
consistent with a SOS function by NEP binding to this
promoter cluster of the atpB/E operon. We conclude that, if
the “correct” functional sigma factor is not available for
PEP at the critical time in development, the sigmaindependent usage of NEP promoter clusters temporally
ensures RNA synthesis and survival of the mutant line.
P04: 11
Metabolic control of seedling development by invertases
Bonfig K.1, Berger S.1, Fatima T.1, Gonzalez M.2 and
Roitsch T.1
1
Julius-Maximilians-Universität Würzburg, Germany;
2
Centro de Investigaciones “Isla de la Cartuja", Sevilla,
Spain; [email protected]
Invertases are important enzymes in higher plants which
are involved in regulating developmental processes and
responses to external factors. In a functional approach the
role of invertases was investigated using transgenic plants
ectopically expressing inhibitor proteins to decrease
invertase activity. For generating specific effects, these
inhibitor proteins were expressed in Arabidopsis under the
control of synthetic promoters consisting of tetramers of
pathogen-inducible elements which were reported to yield
low constitutive expression. Unexpectedly, seedling growth
of putative transgenic plants was arrested at the four
leafstage. Analysis of ß-glucuronidase activity of
corresponding reporter gene lines revealed a correlation of
the growth arrest with high activity of these promoters in
seedlings grown under tissue culture conditions. The
negative effect of invertase inhibition on seedling growth
was substantiated by transgenic tobacco plants expressing
an invertase inhibitor under control of a tetracycline
inducible promoter. Ectopic induction of the invertase
inhibitor during early seedling development resulted in a
reduced fresh weight of seedlings. The importance of
invertase in seedling development is further supported by
POSTER ABSTRACTS
11
P04
results of expression profiling of invertases in Arabidopsis,
which was confirmed by expression analyses. The mRNA
for two vacuolar invertases and a cell wall invertase are
specifically and strongly expressed during seedling
development. These complementing results demonstrate
that invertase activity is required for normal seedling
development.
P04: 12
Microdissection of developing barley grains and cDNA
array analysis of selected tissues
Thiel J., Weier D., Strickert M., Wobus U. and Weschke
W.
Leibniz-Institut für Pflanzengenetik und
Kulturpflanzenforschung (IPK); [email protected]
Seed development of plants proceeds in a gradual manner
following a defined time scale of differentiation in
successive tissues. In this study, microdissection and cDNA
array analysis of selected tissues was established to analyse
regulatory cascades in developing barley grains based on
the mRNA expression level of 12.000 seed-expressed
unigenes. We optimised fixation and embedding
procedures as well as mRNA amplification techniques to
generate high-quality radioactively labelled probes for
large-scale expression analysis. Expression analysis data of
ethanol:acetic acid-fixed caryopses showed a high
correlation to results generated from untreated seeds of the
same developmental stage, demonstrating that mRNA
amplification and probe preparation as done in this study is
a feasible way for cell- and tissue-specific gene expression
profiling in barley seeds. Compared to the whole caryopsis,
identification of differently expressed genes in the nucellar
projection revealed the potential of this methodical
approach for discovering new tissue-specific gene
regulators during barley seed development.
P04: 13
Molecular and functional characterization of a slave
oscillator in the circadian system of Arabidopsis
thaliana
Streitner C., Schoening J., Danisman S. and Staiger D.
Molecular Cell Physiology, Bielefeld University, D-33615
Bielefeld, Germany; [email protected]
AtGRP7 codes for a glycine-rich RNA binding protein
which oscillates in a circadian manner with a peak in
protein amount at the end of the day. The circadian clock
initiates the oscillation by rhythmic transcriptional
activation of the AtGRP7 gene and an autoregulatory
feedback loop completes the devolopment of the rhythm.
Band shift assays reveal sequences in the intron and in the
3’UTR of the AtGRP7 mRNA which function as binding
sites for the protein. According to the autoregulatory
mechanism the accumulation of AtGRP7 protein above a
certain threshold is thought to lead to the emergence of an
alternatively spliced transcript containing a premature stop
codon which prevents the translation of functional AtGRP7
protein. As the AtGRP7 feedback curcuit operates
downstream of the circadian clock, it may act as a slave
oscillator passing circadian signals from the central
oscillator to downstream targets. Microarray technologies
are used to compare wild type plants with AtGRP7
overexpressing plants and with RNAi-plants displaying an
highly reduced level of AtGRP7 expression in order to find
target transcripts. By further analysing the overexpressing
plants as well as AtGRP7 knock out plants we aim to
12
POSTER ABSTRACTS
identify pathways beyond the clock which are affected by
AtGRP7.
P04: 14
Nuclear factors involved in regulation of leaf senescence
Humbeck K., Barth O., Zschiesche W. and Sommer N.
Martin-Luther Universität Halle-Wittenberg, Germany;
[email protected]
The developmental switch from a mature to a senescent
leaf involves massive redirection of gene expression. While
a lot of genes are down-regulated, there are also many
genes which are up-regulated. Regulatory processes
underlying this senescence specific differential gene
expression are still widely unknown. In this presentation
we focus on two factors involved in the regulation of leaf
senescence. The first one is the influence of chromatin
structure on senescence specific gene expression. Changing
levels of the epigenetic control factor SUVH2 (histone
methyltransferase) affect the course of leaf senescence as
demonstrated by measurements of the PSII efficiency.
Overexpression of the SUVH2 gene results in a delay of
leaf senescence and the induction of senescence associated
genes is repressed, while photosynthesis related genes are
down-regulated in a similar way as in the wild type.
Accordingly, a SUVH2-mutant shows accelerated leaf
senescence on physiological and molecular level. These
results indicate that epigenetic mechanisms are partly
involved in the regulation of leaf senescence. Another
factor possibly involved in the regulation of leaf senescence
is a protein of the novel HIPP protein family. These
proteins contain a heavy metal associated domain, an
isoprenylation motif and a nuclear localization signal. One
member of this group is induced during leaf senescence. A
correspondent Arabidopsis mutant shows a clear effect on
leaf senescence when compared with the wild type
indicating a function of this HIPP protein in leaf
senescence.
P04: 15
Plastid Sigma Factor ATSIG6 is crucial for Arabidopsis
Development
Loschelder H., Schweer J. and Link G.
Ruhr-Universität Bochum, Germany;
[email protected]
Chloroplasts are an essential part of plant cell architecture
and physiology. These plant cell organelles contain their
own genetic system consisting of DNA and a full set of
proteins for gene expression. Transcription involves at least
two different types of enzymes, termed Nuclear-Encoded
Polymerase (NEP) and Plastid-Encoded Polymerase (PEP).
PEP is a multi-subunit complex resembling that of
eubacteria, where the a, b and b´ core subunits assemble
with s (sigma) specificity factor(s) to form the initiation
competent holoenzyme. Sigma factors are the principal
regulators of transcription in bacteria and, regarding
phylogenetic relationships, it comes as no surprise that
chloroplasts contain such factors. The sigma proteins are
encoded by nuclear genes – in higher plants usually as a
small gene family. In the model plant Arabidopsis thaliana
six of these genes for plastid sigma factors ATSIG1-6 have
been identified. To help define the in vivo role of individual
members, we have investigated an Arabidopsis knockout
line with a Sig6 mutant allele that reveals a strong
developmental stage specific (albino) phenotype and
characteristic changes in plastid gene expression. RNA gel
P04
blot hybridization and real-time RT-PCR together indicate
that this factor has a dual developmental role, with both
“early” and “persistent” (long-term) activities. Retransformation of the knockout line with Sig6-wildtype
cDNA established a causal relationship between functional
sigma gene and the resulting phenotype.
P04: 16
Quantitative analysis of cell-type specific gene
expression in the green alga Volvox carteri
Nematollahi G., Kianianmomeni A. and Hallmann A.
Universität Bielefeld, Germany; [email protected]
The multicellular alga Volvox carteri possesses only two
cell types: mortal, motile somatic cells and potentially
immortal, immotile reproductive cells. Volvox is therefore
an attractive model system for studying how cellautonomous cytodifferentiation is programmed within a
genome. Moreover, there are almost completed genome
projects both in Volvox carteri and in the closely related
unicellular alga Chlamydomonas reinhardtii. To identify
cell-type specific expression and to determine relative
expression rates, we analyzed a diversified pool of 39 target
genes by real-time RT-PCR for each cell type. This gene
pool contained previously known genes with unknown
localization of cellular expression, 28 novel genes, and a
few known, cell-type specific genes as a control. The
respective gene products are, for instance, part of
photosynthesis, cellular regulation, stress response, or
transport processes. The real-time RT-PCR data showed
that the expression rate of 10 target genes is higher in
somatic cells than in reproductive cells; expression of 16
target genes is higher in reproductive cells than in somatic
cells. In 13 genes the difference in expression between the
two cell types is insignificant.
Our investigations demonstrate that quantitative real-time
RT-PCR is a favorable approach to analyze cell-type
specific gene expression in Volvox, which can be extended
to a much larger number of genes or to developmental or
metabolic mutants. Our expression data also provide a basis
for a detailed analysis of individual, previously unknown,
cell-type specifically expressed genes.
P04: 17
Reduced expression of F-box protein family member
At1g77000 results in dramatic morphological
alterations in Arabidopsis
Pouraiiouby R.1, Friehe S.1, Schmelzer E.2 and Schlaich
N.1
1
RWTH Aachen, Germany; 2MPI f. Züchtungsforschung,
Köln, Germany; [email protected]
In the process of generating transgenic Arabidopsis lines, a
randomly occurring mutant with a dramatic morphological
phenotype was isolated. This line was named “bushy”
according to the dramatically reduced plant size.
Microscopic observations revealed defects on the cellular
organization of leaves, trichomes and flower organs. In
order to understand the molecular basis of the "bushy"
mutant, T-DNA flanking sequences were isolated showing
that the T-DNA was inserted in the promoter of the
At1g77000 locus. At1g77000 encodes an experimentally so
far uncharacterized F-box protein. F-box proteins regulate
diverse cellular processes including cell cycle transition,
transcriptional regulation and signal transduction. F-box
proteins are part of SCF (Skp1p, cullin, F-box protein)
complexes which mediate protein degradation by the
proteasome. The T-DNA integration resulted in reduction
of transcript levels of At1g77000. For complementation of
the “bushy” phenotype and to study gain-of-gene function,
the CDS of At1g77000 was fused with GFP, c-myc and
HA-tags and will be transformed into homozygous “bushy”
lines. To assess the transcriptional activity of the
At1g77000 gene throughout plant development a 4.2 kb
region upstream of the ATG was fused to the GUS reporter
gene. Results from these experiments will be presented.
P04: 18
Regulatory circuits controlling rhizodermic cell fate
under nutrient deficiency
Schmidt W.1, Perry P.1, Yang T.1, Linke B.2, Chen C.1
and Savage N.3
1
IPMB, Academia Sinica, Taipei, Taiwan; 2Institute of
Biology, Humboldt-University Berlin, Germany;
3
Computational Systems Biology Group, University of
Sheffield, UK; [email protected]
To optimize soil exploration plant roots show high
plasticity which is conferred by changes in cell fate
acquisition
during
post-embryonic
development.
Environmental signals can be superimposed to or integrated
with endogenous developmental programs to best suit the
changing edaphic conditions encountered by plants. In the
root epidermis of Arabidopsis differentiation into either a
root hair or a non-hair cell follows a genetically
determined, position-biased pattern. This pattern is high
plastic in response to external stimuli. Arabidopsis root
epidermal cell fate is particularly responsive to nutritional
signals, leading to an increase in the root’s surface area in
the absence of the essential but immobile minerals such as
iron and phosphate. Forward genetic screens revealed
mutants harbouring defects in the response to a particular
nutrient, indicating that signals are transduced via parallel,
but separate pathways. Cell fate decisions are controlled by
apoplastic and symplastic signaling circuits, involving
intercellular communication and long-range signals from
the shoot. Aided by logic probabilistic models we are
investigating the effect of abiotic signals at the whole plant
level and by single cell type-expression profiling.
Epigenetic processes such as the acetylation of core
histones are critical for the integration of the signals at an
early state of the signaling cascade and are crucial for the
cell specification in response to changing bio-availability of
immobile nutrients.
P04: 19
Seed structure and the molecular mechanisms that
control germination
Linkies A.1, Müller K.1, Wenk M.1, Meinhard J.2,
Hermann K.1, Machackova I.3, Fischer U.2 and Leubner
G.1
1
Albert-Ludwigs-University, Institute Biology II, Freiburg,
Germany; 2KWS SAAT AG, Einbeck, Germany; 3Institute
of Experimental Botany CAS, Prague, Czech Republic;
[email protected]
The tremendous structural biodiversity of the various seed
covering layers is not only a hallmark of dispersal unit
evolution, but is also of utmost importance for germination
responses to environmental cues and to plant hormones.
Germination commences with the uptake of water by
imbibition of the dry seed or fruit, followed by embryo
expansion. The testa (seed coat) is an ubiquitous, and the
endosperm, a widespread, covering layer of mature seeds.
We are studying the role of the testa and the endosperm
during the germination of Solanaceae (e.g. tobacco) and
POSTER ABSTRACTS
13
P04
Brassicaceae (Arabidopsis thaliana and Lepidium sativum)
seeds, and the role of the pericarp (fruit coat) during sugar
beet germination. Endosperm weakening appears to be a
prerequisite for the germination and is controlled by
antagonistic interactions between the inhibiting hormone
abscisic acid (ABA) and the promoting hormones ethylene
and gibberellins. Genes and molecular mechanisms
involved in this process are investigated in Solanaceae and
Brassicaceae seeds by reverse genetic approaches.
Evidence for the control of sugar beet germination by a
novel type of ABA-ethylene antagonism that involves the
pericarp and an embryo-mediated active ABA extrusion
system is presented. Transgenic seeds and/or experimental
removal of the various seed covering layers are used to
study the molecular mechanisms that control germination.
P04: 20
Studies of Pti1-kinases in Maize reveal different
subcellular protein localizations and suggest functions
in different but evolutionary conserved processes
Buchert E.1, Pinto S.2, Herrmann M.1, Kluth J.1, Pusunc
S.1, Wienand U.1 and Lorbiecke R.1
1
Biozentrum Klein Flottbek, Universität Hamburg,
Germany; 2Deutsches Krebsforschungszentrum,
Heidelberg, Germany; [email protected]
The tomato kinase Pto confers resistance to specific strains
of Pseudomonas syringae pv. tomato by induction of genefor-gene mediated defence mechanisms including
hypersensitive response (HR). In the signal transduction
pathways induced by Pto, the cytoplasmic serine/threonine
kinase LePti1 is a target of Pto phosphorylation and
involved in HR.
In order to study Pti1 gene functions in maize we cloned
four putative Pti1-kinases: ZmPti1a, b, c and d. It could be
previously shown that ZmPti1a function is evidently
unrelated to pathogen defence but crucial for pollen
fitness.
In this study we demonstrate that in contrast to ZmPti1a,
ZmPti1b, c and d are predominantly expressed in
sporophytic tissues. Expression of ZmPti1b, the closest
homologue of LePti1 from tomato, was accelerated in
maize kernels after Fusarium graminearum infection. This
finding suggests that ZmPti1b and LePti1 could possess
related functions during plant-pathogen interaction.
GFP fusion studies indicated different subcellular
localizations of maize Pti1 kinases which are presumably
due to diverse N-termini of the proteins. Phylogenetic
comparison between putative Pti1 proteins revealed a
conservation of the diverse N-termini between Pti1 kinases
from mono- and dicotyledonous plants and suggests a
crucial role of N-termini for biological functions of Pti1
kinases. Based on these data an evolutionary conservation
of Pti1 kinases in mono- and dicotyledonous plant is
postulated. However, Pti1 family members of a plant seem
to act in different tissue types and as regulators of different
developmental programs.
14
POSTER ABSTRACTS
P04: 21
The pollen-specific protein kinase ZmPTI1a from maize
co-localizes with callose deposition and facilitates a
competitive advantage to the male gametophyte
Herrmann M.1, Pinto S.2, Kluth J.1, Wienand U.1 and
Lorbiecke R.1
1
Universität Hamburg, Biozentrum Klein Flottbek,
Germany; 2Deutsches Krebsforschungszentrum,
Heidelberg, Germany; [email protected]
The serin-threonin protein kinases LePTO and LePTI1 (Pto
interactor 1) from tomato are known to be regulators of
gene-for-gene resistance and hypersensitive response (HR)
reaction after Pseudomonas syringae infection. However,
the exact role of LePTI1 in pathogen response signaling is
uncertain. In the process of deciphering the function of
genes involved in maize fertilization, we cloned a
functional PTI1 kinase from maize (Zea mays L.).
ZmPTI1a was examined in terms of its expression and
function. In contrast to LePTI1 from tomato, expression of
ZmPTI1a is pollen-specific. Maize plants in which
ZmPTI1a expression was silenced by RNAi produced
pollen with a decreased competitive ability compared to
wild type pollen. Stable expression of GFP fusions
demonstrated that ZmPTI1a is sequestered at the pollen
plasma membrane due to N-terminal acylation and is
localized as a distinct annulus-like structure. This structure
co-localized with regions of callose (1,3-ß-glucan)
deposition. Co-localization of ZmPTI1a and callose was
also observed at different stages of pollen mitosis and
during pollen tube germination. Thus, it seems conceivable
that ZmPTI1a is involved in crucial stages linked to callose
deposition during pollen maturation.
Because pollen-sporophyte interaction and pathogen
induced HR show certain similarities, e.g. callose
deposition, Ca2+- and oxidative-stress-signaling, it is
hypothesized that plant PTI1-kinases act as general
components in evolutionary conserved signaling processes
but during different developmental programs and in
different tissue types.
P04: 22
The putative GDSL-like lipase ZmJR2 is transiently
expressed during maize (Zea mays L.) kernel
development
Beneken C., Wienand U. and Lorbiecke R.
Biozentrum Klein Flottbek, Universität Hamburg,
Germany; [email protected]
The ZmJR2 gene from maize was identified within the
scope of a subtractive hybridization screening for
differentially expressed genes during early kernel
development.
According to sequence analyses the putative ZmJR2
protein can be related to a rather new subclass of lipolytic
enzymes, the GDSL-like lipases.
Beside the first-described GDSL-family of prokaryotic
secretory lipases, the distinct GDSL-motif could recently
be found in several plant proteins e.g. in Arabidopsis, Rice
and Maize. Some of these GDSL-like lipases were
suggested to be involved in regulatory pathways, e.g.
salicylic
acid
and
methyl-jasmonate
signalling.
Nevertheless, the biological function of this protein class is
still unclear.
ZmJR2-Expression was analyzed in different tissues and
developmental stages of maize. Transcripts were found in
ovaries, maize kernels, coleoptiles and primary roots.
However, strongest expression of ZmJR2 could be detected
P04/P05
Ranunculales order, Eschscholzia californica (California
poppy). I will present data on the very effective method of
Virus-Induced Gene Silencing (VIGS) for repressing gene
expression with extremely high efficiency in plants which
prove recalcitrant to transformation. Our group uses this
method successfully to obtain functional data for regulators
of flower development.
VIGS allows functional characterisation of genes from
phylogenetically informative species not amenable to gene
function studies so far and provides an extremely useful
tool for future plant evo-devo work.
during early maize kernel development, with an increasing
expression level up to 10 days after pollination and a
following steady decrease of ZmJR2-transcripts.
Transient expression studies of a ZmJR2:GFP fusion
protein demonstrated ZmJR2 to be transported into the
endoplasmic reticulum, suggesting a subsequent secretion
of ZmJR2.
Based on these approaches the ZmJR2 protein is
hypothesized to play a role during kernel development, but
also accomplishes functions in other non-green tissues.
Current experiments are conducted to analyse ZmJR2
function with respect to a putative involvement in either
energy supply or signalling pathways during maize
development.
P05: EARLY LAND PLANTS
P04: 23
P05: 1
Transformation-an itinerary for functional
characterization of genes for carpel development in
Yellina A., Wege S., Lange S. and Becker P.
Universität Bremen, Germany; [email protected]
Though the genetic architecture of flower development has
been extensively studied in Arabidopsis, there is a need to
have a basal eudicot species to get a clear view of
molecular principles for its ontogeny during evolution.
Eschscholzia californica is found to be the expedient model
species because of its phylogenetic position and its
amenability for transformation.
I am focusing my research on the important carpel
development genes CRABS CLAW, AGAMOUS and
SPATULA in E.califirnica. Functional characterization of
the genes via Agrobacterium mediated transformation
proved to be the best method. Over-expression of genes
with CaMV35S::ORF cassette and knock-down expression
through ihRNAi approach are used for stable
transformation. However transient expression through virus
induced gene silencing is found to be rapid and also reliable
method. We employ Tobacco rattle virus based vectors to
silence poppy genes involved in carpel development. We
have obtained robust phenotypes when silencing the poppy
orthologs of the Arabidopsis CRABS CLAW and
AGAMOUS genes. Stable transformation using unripe
seeds as the explant proved to be appropriate source of
explant for tissue culture and transformation.
We aim to functionally analyze the main candidate genes
for carpel development in poppy and compare their
function with respective orthologous genes from distantly
related species like Arabidopsis and rice.
P04: 24
Virus-Induced Gene Silencing is a highly effective tool
for gene function studies in phylogenetically valuable
species
Wege S., Lange S., Stammler A. and Becker A.
Extremely long survival of a nad7 pseudogene and
peculiar rearrangements in the mitochondrial DNA of
liverworts
Wahrmund U., Groth-Malonek M., Polsakiewicz M.
and Knoop V.
Universität Bonn, IZMB, AG Molekulare Evolution,
The transfer of the nad7 gene encoding a subunit of the
mitochondrial NADH ubiquinone oxidoreductase from
mitochondrion to nucleus in the liverwort Marchantia is
not only the sole documented example of land plant
mitochondrial gene transfer outside of the angiosperms but
also the only known example of recent gene transfer
affecting a core component of complex I of the respiratory
chain. Sampling a phylogenetically wide array of liverworts
we surprisingly found that nad7 is generally present as a
pseudogene in mitochondrial DNA with varying modes of
degeneration through point mutation or indels in the
marchantiid vs. jungermanniid liverwort clades, rather
suggesting a very ancient gene transfer and surprising longtime persistence of the pseudogene copy in this old land
plant clade. However, we identified intact, transcribed and
spliced mitochondrial genes in the isolated liverwort
lineages Haplomitrium and Treubia, corroborating their
assumed basal-most placement in the liverwort phylogeny
as presumed sister groups. Looking at the typical
pyrimidine exchange type of RNA editing in land plant
organelle transcripts, a multitude of C-to-U RNA editing
events are identified in Haplomitrium, whereas no single
editing is necessary for correct expression of nad7 in
Treubia. The genes for tRNAs Alanin and Threonine
preceed nad7 in a conserved gene cluster in algae and the
moss Physcomitrella. In contrast, trnT is lost from the
trnA-nad7 intergenic region in liverworts, but strikingly
then reinserted later in evolution in inverted orientation in a
subclade of marchantiid liverworts.
Our understanding of the molecular bases for flower
development in model plants like Arabidopsis, petunia,
Antirrhinum, and rice has made major advances in the past
15 years. However, as all these species are highly derived
eudicots or monocots they provide the base for only limited
information on evolutionary questions. To better
understand the evolutionary trajectories leading to flowers
and the enormous variations in floral forms we know today
we have established a basal eudicot model plant from the
POSTER ABSTRACTS
15
P06
P06: ECOLOGY AND
ECOPHYSIOLOGY OF
ALGAE
P06: 1
Balancing the energy from absorbed photons to new
biomass in the Diatom Phaeodactylum tricornutum
under dynamic light conditions and N-limitation
Wagner H., Jakob T., Stehfest K. and Wilhelm C.
Universität Leipzig, Germany, Biologie I Pflanzenphysiologie; [email protected]
In this study we have determined the energy balance of
absorbed photons to biomass in a diatom under dynamic
light conditions and N-limitation. For this purpose
fluorescence based measurements of electron transport
rates are an established tool to assess photo-physiological
fitness but can not be easily related to biomass production.
Therefore, the amount of electrons transported by
photosystem II measured by PAM-fluorescence have been
related to gas exchange rates and to the newly formed
biomass. We found that under high nutrient conditions the
quantum efficiency of carbon-related biomass production
(Φc) and the electron requirement of carbon production were
found to be strongly controlled by the light climate. Under
N-limited conditions the light climate was less important
for the efficiency of carbon related biomass production.
Instead, cells acclimate to N-Limitation on the levels of
light absorption, of the dissipation of excessively absorbed
light and of the dissipation of excessively released
photosynthetic electrons. It became evident that Nlimitation induced pronounced changes in the composition
of macromolecular compounds measured by FTIR. Thus,
N-limitation determines the degree of reduction of the
biomass as well as the metabolic costs of C-incorporation.
Since the metabolic costs are not predictable from the
photosynthesis rates, electron transport rates as well as gas
exchange measurements during the light phase can severely
mismatch the true energy storage in the biomass especially
under high-nutrient in combination with dynamic light
conditions.
P06: 2
Biodiversity of extreme acidotolerant microeukaryotes
in acidic mining lakes in Lusatia and Upper Palatinate
(Germany)
Kraft C., Fink N. and Huss V.
Friedrich-Alexander-Universität Erlangen-Nürnberg,
Eukaryotic microorganisms in extreme acidic biotopes
stand severe environmental conditions such as low pH and
high concentrations of heavy metals. We have studied by
"Environmental PCR" microeukaryotic diversity in two
acidic mining lakes in Germany with a pH of 2.3 and 2.9.
After total DNA isolation of lake water filtered through a
100 µm mesh nylon net, the 18S rDNAs were amplified
with universal and group-specific primers and cloned into
the TOPO vector. Reamplified inserts were restricted with
HaeIII and clones with diverse restriction patterns were
analyzed by sequencing and subsequent phylogenetic
classification. The 18S rRNA analyses showed that number
and diversity of microeukaryotes in these acidic lakes is
16
POSTER ABSTRACTS
low. Most abundant is the chlorophyte Chlamydomonas
acidophila, a dominant species in many acidic
environments. A few clones were identified to belong to the
trebouxiophytes, euglenophytes, chytridiomycetes, ciliates,
and Cercozoa. Highest diversity was found among
straminopiles
with
representatives
of
diatoms,
eustigmatophytes, oomycetes, and especially chrysophytes.
Many of the determined sequences are closely related to
other environmental sequences or to defined taxa, but we
also found several clones, which could not be classified on
a family or order level. Interestingly, we repeatedly found
in both lakes a 18S rRNA sequence, which could not be
clearly associated to any known eukaryotic lineage.
Currently, we use the Fluorescence In Situ Hybridization
(FISH) technique to visualize the unknown eukaryote.
P06: 3
Diversity and Abundance of Epipelic Diatoms in two
polluted sites of Zayandeh rood River, Iran.
Nejadsattari T.1, Movahedi Naini Z.1, Afshar zadeh S.2
and Fallahian F.1
1
Islamic Azad University, Science and Research Branch,
Iran (Islamic Republic of); 2Department of Biology,
Faculty of Science, University of Isfahan, Isfahan,I;
[email protected]
A study on epipelic diatoms of two polluted sites in
Zayandeh rood River , Iran, Was conducted from January
2006 through August 2006. Samples were gathered from
two stations of each site at biweekly intervals, one station
located before inflow of pollutants and the second after
that. In this study 118 species of diatoms were identified,
belonging to 30 genera. High species diversity were
observed in winter in all stations (H'=3.4, 3.2, 3.6 and 3.3
in stations 1, 2, 3 and 4 respectively). Cymbella, Navicula,
Nitzschia and Gomphonema had high percent abundance,
among which percent abundance of Cymbella at stations
two and four were 21.7% and 21%, respectively. Whereas,
at stations 1 and 3 it was high 26% and 25%). The study
revealed that at low pH's there were high species diversity
at winter, also high species diversity were observed at high
EC.
P06: 5
Ecophysiological studies of five field-grown macroalgae
from Strait of Magellan (Chile) to enhanced ultraviolet
radiation
Rautenberger R.1,2 and Bischof K.1
1
Institute for Polar Ecology, University of Kiel, Germany;
2
Department of Marine Botany, University of Bremen,
The annual establishment of an “Antarctic ozone hole”
during austral spring between September and November
every year results in increasing irradiances of solar UV-B
radiation on earth's surface. During that time the “Antarctic
ozone hole” extended as far as north to include the southern
tip of South American continent several times. For coastal
ecosystems, macroalgae represent key components
providing food and shelter for associated organisms. They
might particularly be affected by ultraviolet radiation
occurring in eulittoral and sublittoral because of both its
penetration into the water column at high tide and the lack
of the attenuating water column at low tide.
For the study of the susceptibility to UV radiation, five
species of green, brown and red macroalgae were collected
in both tidal locations and exposed to artificial UVradiation in the laboratory. Both UV-A and UV-B radiation
P06
became stressful in each species indicated rather by a
reduced photosynthetic efficiency (Fv/Fm) than an
unchanged maximum relative electron transfer rate
(ETRmax.) during UV-exposure. Reduction of Fv/Fm was
rapidly reversible after removal of UV radiation therefore
possibly suggesting a transient down-regulation of
photosynthesis. Therefore, Fv/Fm seems to be a more
sensitive parameter for UV-induced stress.
All species collected at the Strait of Magellan seem to be
well adapted to enhanced UV radiation. Furthermore, there
is no evidence about the relationship of susceptibility to
UV radiation and position at the shore.
P06: 6
Efficiency of biocides against microalgal growth on
facades
Gladis F., Karsten U. and Schumann R.
University of Rostock, Institute of Biological Sciences,
Applied Ecology G; [email protected]
Microbial growth on building facades can cause
deterioration of the material and is considered a first step in
the formation of biofilms incl. molds. Therefore, biocides
are widely used in plaster and paints.
The aim of the present study was to analyse the effects of
two permitted biocides, one isothiazoline and a triazine, on
five different isolates of unicellular green algae.
Additionally, nanoparticles of zinc oxide, which generate
hydroxyl radicals under ultraviolet radiation, were tested.
While there was no relationship between biocide tolerance
and original habitats of the isolates, the sensitivity
decreased with the increasing growth potential of the
isolates. Thus, the choice of algal species for toxicity tests
is important.
The effects of the biocides on photosynthetic efficiency,
pigment degradation and composition, membrane integrity
as soon as hydrolytic activity were also tested. Triazine
acted also against non-target phototrophs, because it
directly affects photosynthesis, but this substance was not
lethal. While the maximum quantum yield and the growth
declined under exposure, all other parameters were not
inhibited. Thus, the formation of resistant algae is likely. In
contrast, the isothiazoline inhibited enzymes in the central
metabolism and affected all analysed parameters. This
general toxicity endangers even more non-target organisms.
The nanoparticles were highly efficient against all vitality
parameters. Due to their catalytic, i.e. sustainable,
characteristics, such particles have a great potential against
algal growth on building materials.
P06: 7
Epiphytic and Epilithic Diatoms Flora of Kan River,
Iran.
Mehrani Adl M., nejadsattari t., alaghehband n. and
jamalloo f.
AZAD UNIVERSITY, Iran (Islamic Republic of);
[email protected]
Epiphytic and Epilithic Diatoms Flora of Kan River,
Iran.Mehrani Adl,M1., Nejadsattari,T1., F.Jamaloo2,
N.H.Alaghehband1.1. Department of Botany, Science and
Research Branch Islamic Azad University. Tehran.
Iran.2.
Islamic Azad University, Qum branch. Qum,
Iran. Epilithic and Epiphytic diatoms flora of Kan River,
Iran, were investigated from Novamber 2006 through May
2007. triplicate samples were gathered from 6 site along
River.
Simultaneousty
physiochemical
analysis,
tempreture, DO, pH and EC, Na+, Ca2+, Mg2+, Sio2 , No3-
and Po43- were determined. In this study 48 species from
14 genera of diatom were identified. Navicula with 10 and
Cymbella with 8 species had high species diversity. High
papulation density of epilithic and epiphytic diatom during
study were 21.52 ×103 cell/cm2 and 22.4×103 cell/cm2
respectivery.Study revealed that pollution in water
decreased species diversity.Key words: epilithic , epiphytic,
Bacillariophyceae, Kan River .
P06: 8
Green Algal Biofilms - The Aeroterrestrial Way of Life
Gustavs L.1, Schumann R.1, Lembcke S.1, Friedl T.2 and
Karsten U.1
1
Institute of Bioscience, Applied Ecology, University of
Rostock, Germany; 2Experimental Phycology and SAG,
University of Göttingen, Germany; [email protected]
Aeroterrestrial green algae colonize many natural and
artificial surfaces such as soils, barks and stones, as well as
roof tiles and facades. Green biofilms investigated so far in
Northeast
Germany
are
dominated
by
the
Trebouxiophyceae Apatococcus lobatus, while Chlorella
spp., Stichococcus spp. and the Streptophyte spp.
Klebsormidium are less abundant. Compared to freshwater
and marine habitats, aeroterrestrial algae are generally
much more exposed to harsh and rapidly changing
environmental conditions which may cause desiccation,
freezing or damage through high insolation (PAR and UV).
Ecophysiological research focussed on growth and
photosynthetic performance of strains isolated from
aeroterrestrial habitats. Abiotic conditions such as
temperature, PAR and water availability were varied in
order to characterize the ecological tolerance and limits of
these organisms. All data indicate euryoecious response
patterns. Synthesis and accumulation of low molecular
weight carbohydrates (LMWCs) and mycosporine-like
amino acids (MAAs) represent important adaptation
strategies to the aeroterrestrial habitat. LMWCs function as
compatible solutes, maintain cellular homeostasis and, thus,
prevent cells from desiccation and damage through
freezing, respectively. MAAs function as UV-sunscreen
components and protect many vital functions of the cells.
Ecophysiological as well as biochemical results presented
well explain the performance and ecological success of
aeroterrestrial green algae.
P06: 9
Interactions between diatoms and bacteria: a study on
epilithic biofilms from Lake Constance
Bruckner C., Bahulikar R. and Kroth P.
Department of Biology, University of Konstanz, Germany;
[email protected]
Benthic freshwater biofilms are organic layers consisting of
a huge variety of organisms interacting with each other.
Diatoms often dominate benthic biofilms and secrete large
amounts of extracellular polymeric substances (EPS). We
purified more than 30 benthic freshwater diatom strains to a
bacteria-free (axenic) condition. Interestingly, about 90%
of these axenic diatom strains do not show any biofilm
formation in the absence of bacteria. Thus we analysed cocultures of specific bacteria from the littoral zone of Lake
Constance and axenic diatom strains and found the
following effects: 1) The interaction of diatoms and
bacteria may induce biofilm formation and changes in
diatom colony morphology. Experiments with bacterial
culture supernatants indicate that soluble molecules of
POSTER ABSTRACTS
17
P06
bacterial origin may be responsible for this effect. 2) The
growth of most diatoms seems to be enhanced generally in
the presence of different bacteria. 3) Bacteria may influence
the secretion of polysaccharides by the diatoms, while the
carbohydrate composition is less affected. 4) On solid
media most of the diatoms tested do not grow any more if
bacteria are absent. From our experiments we conclude that
the interactions between diatoms and bacteria are key
events for the formation of such biofilms in nature.
Understanding the nature of these interactions and
identification of the involved factors may lead to
explanations how photoautotrophic biofilms are
established.
P06: 10
INTERACTIVE EFFECTS OF RADIATION,
TEMPERATURE AND SALINITY ON THE ARCTICENDEMIC RED ALGA DEVALERAEA
RAMENTACEA
Fredersdorf J.1,2, Karsten U.3 and Bischof K.1
1
Department of Marine Botany, University of Bremen;
2
Alfred-Wegener-Institute for Polar and Marine Research,
Bremerhaven; 3Institute of Biological Sciences–Applied
Ecology, University of Rostock; [email protected]
Devaleraea ramentacea represents one of the few red
macroalgal species endemic to the Arctic. Previous
unifactorial experiments revealed a generally high tolerance
of D. ramentacea to variation in abiotic conditions.
Although in the field the effects of photosynthetically
active (PAR) and UV-radiation, temperature and salinity
are usually interconnected, studies on interactive effects on
its physiology are scarce. Mesocosm-experiments under
natural solar radiation as well as laboratory set-ups under
defined, artificial radiation conditions, at three different
water temperatures and at different salinities were
conducted at Spitsbergen in order to reveal physiological
responses of D. ramentacea under multiple abiotic stresses.
Photosynthetic measurements confirm the high tolerance of
adult sporophytes of D. ramentacea towards single and
combined stress factors. Experimentally induced changes in
the content of UV-screening mycosporine-like amino acids
(MAA) and the enzymatic activity of superoxid-dimutase
were studied. A specific characteristic of D. ramentacea
under changing abiotic conditions is the greening of the
tips. The factors inducing the loss of phycobiliproteins and
the changes in physiological performance in the affected
thallus fragments are addressed. Results will be discussed
in the context of the species distributional patterns.
P06: 11
Microphytobenthos of the Arctic Kongsfjord
(Svalbard): Ecophysiology and net photosynthesis in
situ quantification by benthic chambers
Wölfel J.1, Schumann R.1, Wiencke C.2 and Karsten U.1
1
University of Rostock, Germany; 2Alfred Wegener
Institute for Polar and Marine Research, Germany;
[email protected]
A lot of research attention was aimed to polar regions to
estimate the impact of climate changes. But basic
information on primary production are still lacking for most
algal groups, particularly for microphytobenthos. In
addition, the physiological tolerances and optima of benthic
diatoms under the prevailing environmental conditions are
almost unknown for Arctic waters. Therefore, in this study
special attention was paid to the microphytobenthos
18
POSTER ABSTRACTS
consisting to 99% of diatoms in an Arctic fjord (Svalbard).
A new measuring method for O2 and, thus, for net
photosynthesis using benthic chambers in combination with
optodes was evaluated. Patches of microphytobenthos
covering sandy sediments at water depths down to 30 m
showed biomasses of up to 50 mg Chl a m-2. Mapping of
the in situ O2 production at different water depths allowed a
first evaluation of primary production, and thus its
ecological importance for the benthic food webs. The
diatoms are well adapted to the ambient irradiances as
demonstrated by laboratory studies. The abundant species
Cylindrotheca closterium Reimann & Lewin and Nitzschia
cf. aurariae Cholnoky showed fast chances in the
characteristics of their PI (photosynthesis versus
downwelling irradiance) curves after exposure to changed
radiation conditions. Higher photon fluence rates were
better compensated when the diatoms could recover some
hours in darkness, for example by migration into the
sediment during the polar day. These data confirm that
Arctic diatoms efficiently optimize their photosynthetic
apparatus to the current radiation conditions.
P06: 12
MORPHOLOGICAL AND PHYSIOLOGICAL
FEATURES OF AERO-TERRESTRIAL ALGAE
GROWING IN ASSOCIATION WITH FUNGI ON
TREE BARKS
Freystein K., Reißer W. and Salisch M.
Universität Leipzig, Germany;
[email protected]
Tree barks form a very special habitat and are inhabited by
a great variety of organisms. Especially green biofilms
cover the surface of nearly every tree. Those biofilms are
mainly formed by green aero-terrestrial algae and fungi.
Symbiotic interactions of algae and fungi are well known in
lichens. However algae-fungi-interactions within green
biofilms are not very well examined.
To observe the native structure of those biofilms we used
cryo-cut technique. On barks of Aesculus hippocastanum
and Quercus robur we observed a great variety of fungal
and algal interaction. By light microscopy we compared
differences in morphology (e.g. size and structure of the
chloroplast) and size of the algal cells which depend on
presence or absence of fungi. In order to study the
ecological and physiological aspects of that algae-fungiinteraction we cultivated algal species both axenic and in
cultures contaminated by fungi - “mixed” cultures. Those
cultures showed great differences in growth rate and
photosynthetic quantum yield. While algae of axenic
cultures grew constantly, algae of mixed cultures grew
three times faster. Within stress experiments mixed cultures
had shown a better revitalisation after drying for several
weeks. They did better compensation in experiments with
nutrient depletion. They grew constantly in high levels of
photosynthetic quantum yield, while axenic cultures
showed great variations. Experiments suggest that
associations between algae and fungi allow to a better
adaptation to environmental conditions.
P06
P06: 13
NITROGEN REQUIREMENTS OF LESSONIA
NIGRESCENS BORY AND LESSONIA
TRABECULATA VILLOUTA & SANTELICES
(PHAEOPHYCEAE, LAMINARIALES)
EDDING M.1,2, TALA F.1,2, CORTES C.1 and
TOLEDO P.1,2,3
1
UNIVERSIDAD CATOLICA DEL NORTE, Chile;
2
CIDTA, Chile; 3CEAZA, Chile; [email protected]
L. nigrescens is one of the main algae growing along the
south east Pacific coast. L. trabeculata is the main subtidal
kelp in the northern central Chile and southern Peru. It has
been observed that ammonia and other nitrogen sources
may affect the development of Lessonia. Lessonia can be
utilized to bioremediate the waste water capturing
nitrogenated compounds liberated from the cultivation
systems. Although cultivation techniques have been
developed for Lessonia there is little information on the
nitrogen requirements of sporophytic phases. The purpose
of the present work was to determine the uptake of
nitrogenated compounds by L. nigrescens and L.
trabeculata. Selected fronds, stipes and holdfast were
cleaned, washed with tap water and dried at 60ºC. The
material was grounded for N2 analysis. Nitrogen uptake,
nitrogen water concentration and tissue levels were
determined by Kjeldahl (NKT) and Standard methods of
analysis. Experiments to observe N2 absorption were
realized in the laboratory. The results suggested that
nitrogen compounds were exudates from L. nigrescens and
L. trabeculata and that N2 in the tissues is affected by the
absence of this ion in seawater. Also it was observed that
there were significant differences in the N2 pool between
plants collected in protected environments and exposed to
the surge and wind. This observation confirms the effect of
frond erosion and the contribution of N2 into the
surroundings waters.
P06: 14
Screening of UV-A and UV-B radiation in marine green
macroalgae
Pescheck F.1, Bilger W.1 and Bischof K.2
1
Botanical Institute, University of Kiel, Germany;
2
Department of Marine Botany, University of Bremen,
Species-specific differences in UV-B resistance have been
revealed to co-determine the vertical structure of
macroalgal communities even under non-depleted ozone
conditions. Although green macroalgae inhabit usually the
uppermost positions at the shore and are thus exposed to a
greater extent to UV-B radiation than red and brown algae,
almost no information about UV-protection strategies is
available from this group. The synthesis of UV-absorbing
compounds may provide an efficient protection by
screening. In the presented study a technique based on
chlorophyll fluorescence was validated and used to assess
UV-screening around 313 nm and 366 nm in a
taxonomically wide range of marine green macrophytes
isolated from polar, temperate and tropical habitats. The
aim was to determine if there are adaptive differences in
UV-screening between species of high and low UV
environments. Only 35 % of a total of 48 investigated
isolates showed significant UV-A screening and significant
UV-B screening was observed in 67 %. While no relation
was observed between the respective algal habitat and
screening capacity, species with significant screening were
found almost exclusively in the orders of Cladophorales,
Valoniales and Prasiolales. Induction of UV-B screening by
experimental exposure to UV-B did only occur in some
species. It is shown that generally UV-screening is low in
green algae, which may thus employ other physiological
mechanisms of UV-protection. Furthermore, in a collection
of 12 isolates, damage to photosystem II was shown to be
linearly related to UV-B screening.
P06: 15
Species composition and community structure of
epipelic diatoms of Kan river, Iran.
Alaghehband N., nejadsattari t., mehrani adl m. and
jamalloo f.
science and reaserch branch islamic azad university, Iran
(Islamic Republic of); [email protected]
Epipelic diatoms from Kan river, Iran were sampled by a
coring device at 15 days intervals from November 2006 to
May 2007 . Physicochemical factors were determined
during sampling period . Diatoms were fixed with 3٪
formalin and transferred to the laboratory in cool containes
. In this study 40 species of diatoms were identified .
Nitzschia with 7 and Cymbella with 6 species showed
high species diversity . Population density of diatoms
were ranged from 24.90×103 cell.cm-2 during January 2007
to7.3×103 cell.cm-2 during May 2007 .It seems that
population density of different species were influenced by
pollution rate and temperature . Key words : Kan river
,Epipelic, Bacillariophyceae .
P06: 16
The effects of stratospheric ozone depletion and of
global warming on Arctic and temperate kelp species
(Laminariales, Phaeophyceae)
Müller R.1, Christian W.1 and Kai B.2
1
Alfred-Wegener-Institute for Polar and Marine Research,
Germany; 2University Bremen, Germany;
[email protected]
The key species of many temperate and Arctic kelp forests
are strongly constricted in their vertical and latitudinal
distribution by their tolerance to UV radiation and by their
temperature demands. The stages in the life history of
seaweeds most sucseptible to environmental perturbaties
are their unicellular propagation units. Therefore we
determined the temperature- dependent UV- susceptibility
of zoospores of Saccharina latissima and Laminaria
digitata from the Arctic (Spitsbergen) as well as from
temperate waters (Helgoland), of Arctic Alaria esculenta
and of temperate L. hyperborea. The zoospores were
exposed to three radiation conditions (photosynthetic active
radiation PAR, PAR + UV A radiation or PAR + UV A +
UV B radiation) and four temperatures (2, 7, 12, 17 °C).
Subsequently the germination rates were assessed. Under
elevated water temperatures the tolerance of zoospores of
A. esculenta, S. latissima and L. hyperborea to UV Bstress were not changed. Laminaria digitata from the
Arctic, however, improved its UV-tolerance with
increasing temperature. Zoospores of the summer
reproducing L. digitata from Helgoland have their lethal
limit at 19 °C, a temperature often recorded in summer at
Helgoland today. So in the Arctic the upper distribution
limit of L. digitata will increase with rising temperatures
and in the North Sea the southern distribution boundary of
this species will be shifted north. This shows the
considerable effect global change has on seaweed
distribution.
POSTER ABSTRACTS
19
P06/P07
community structure and alter trophic interactions in this
system.
P06: 17
The vacuolar system of Mesostigma viride Lauterborn
(Streptophyta)
Buchmann K. and Becker B.
Universität zu Köln, Germany; [email protected]
The Viridiplantae consist of two phyla: the Streptophyta,
including the Mesostigmatophyceae, and the Chlorophyta.
Formerly, the Mesostigmatophyceae where placed within
the Prasinophyceae, a group of scaly flagellated green
algae. Recent data indicate that Mesostigma is the only
extent flagellated streptophyte alga.
As a freshwater alga Mesostigma has contractile vacuoles
for osmoregulation. Furthermore, the organism possesses
another type of vacuoles, called phosphate-storage vacuole
or lytic vacuole. In my research I want to understand the
function of the vacuolar system of Mesostigma viride. For
an initial characterisation I use light- and transmission
electron microscopical methods.
First results show that Mesostigma has several contractile
vacuoles, which are arranged in a reticular structure
surrounding the flagella pit. To understand the function of
this system in a better way, the effect of different salt
concentrations on the function of the contractile vacuoles is
investigated.
P06: 18
UV radiation and grazing impacts on an intertidal
macroalgal assemblage in Antarctica
Zacher K.1, Roleda M.3, Molis M.2, Wulff A.3, Hanelt
D.4 and Wiencke C.1
1
Alfred Wegener Institute for Polar and Marine Research,
Germany; 2AWI, Helgoland, Germany; 3Marine Ecology,
Göteborg University, Sweden; 4Biozentrum Klein Flottbek,
University of Hamburg, Germany;
[email protected]
While most research on ultraviolet radiation (UVR) was
focused on the effect of UVR on the physiology of
individual organisms, little is known about the impact of
UVR on assemblages in combination with other
ecologically relevant factors. In particular, fieldexperiments on macrophytobenthos are scarce, even more
in the Antarctic region. As macroalgae may be affected by
enhanced UVR due to stratospheric ozone depletion, we
studied the effects of UVR and consumers on early
successional stages of a hard bottom macroalgal
community on King George Island, Antarctica. In a twofactorial
design
32
experimental
units
(PAR+UVA+UVB=280-700 nm; PAR+UVA=320-700 nm;
PAR=400-700 nm vs. grazer–no grazer) were installed for
106 days. In general, biomass and growth rates were very
low. Both UVAR and UVBR showed negative effects
during succession. The UV depleted treatment exhibited a
significantly higher diversity after 106 days of exposure.
Species richness was significantly depressed by UVAR at
the end of the experiment. UVB radiation led to a
significant difference in species composition between the
UV depleted treatment and the one with the total solar
spectrum. Small developmental stages of macroalgae were
particularly sensitive to UVR but spores from intertidal
macroalgae were better adapted to UVR than species
occurring in the subtidal as shown in laboratory
experiments. Both, UV radiation and herbivory exhibit a
significant impact on macroalgal succession in the
Antarctic intertidal. UVR may therefore change the
20
POSTER ABSTRACTS
P07: EVOLUTION OF
ALGAE
P07: 1
Gain and loss of polyadenylation signals during
evolution of green algae
Wodniok S.1, Simon A.1, Glöckner G.2 and Becker B.1
1
Universität zu Köln, Germany; 2Genome Analysis, FLI;
[email protected]
Eukaryotes attach a poly-A tail to the 3' ends of most
nuclear-encoded mRNAs. In animals, fungi and
embryophytes, the signal for polyadenylation contains an
A-rich sequence (NUE) 13 to 30 nucleotides upstream from
the cleavage site. However, the pentanucleotide UGUAA is
used as polyadenylation signal for some genes in
volvocalean algae. We analyzed expressed genes (ESTs)
from streptophyte and chlorophyte algae for differences in
polyadenylation signals. Polyadenylation signals vary
widely in green algae. The different distribution of the
various polyadenylation signals in green algae is discussed
in an evolutionary context.
P07: 2
Is Spirotaenia a new lineage of streptophyte algae?
Gontcharov A., Marin B. and Melkonian M.
Botanisches Institut, Universität zu Köln, Germany;
[email protected]
The genus Spirotaenia has long been considered a member
of the class Zygnematophyceae (Streptophyta) based on
sexual reproduction by conjugation. In contrast to that,
phylogenetic analyses of SSU rRNA and the rbcL genes
placed it outside the class clade associated with
Chlorokybus. Absence of the typical zygnematophycean
1506 group I intron in Spirotaenia corroborated this
divergent position (Gontcharov & Melkonian, 2005).
To study the affiliation of Spirotaenia in more detail, we
sequenced complete nuclear and chloroplast ribosomal
RNA operons as well as the protein-coding rbcL genes in
four species of the genus and created a data set that
included members of all streptophyte algal lineages
including the Zygnematophyceae. It was found that
Spirotaenia has the typical structure of the chloroplast
rRNA operon (16S rDNA-tRNA-Ile(GAU)-tRNAAla(UGC)-23S) that is absent in the Zygnematophyceae.
Remarkably, both tRNAs in Spirotaenia lack an intron, a
feature shared in Streptophyta only by Chlorokybus and
Mesostigma. Individual and combined (ca. 10000 nt)
phylogenetic
analyses
strongly
supported
close
relationships between Spirotaenia and Chlorokybus to the
exclusion of the Zygnematophyceae. This raises a question
whether the mode of sexual reproduction in this alga is
homologous to that in the class Zygnematophyceae (unlike
other conjugates, Spirotaenia species produce two gametes
per cell that are released by cell wall lyses) and whether
members of the genus indeed lack traces of the flagellar
apparatus? It appears that a new lineage of Streptophyta
may be immerging.
P07
P07: 3
Microalgal biodiversity just outside of the housedoor:
aerophytic green biofilms on artificial hard substrates
Hallmann C.1, Mudimu O.1, Karsten U.2, Schumann
R.2, Hoppert M.3 and Friedl T.1
1
Universität Göttingen, Experimentelle Phykologie und
SAG; 2Universität Rostock, Angewandte Ökophysiologie;
3
Universität Göttingen, Allgemeine Mikrobiologie;
[email protected]
Green algal biofilms on articifial hard substrates such as
house facades or roof tiles often cause undesired optical
effects and accelerate biocorrosion. Here we study the
diversity of biofilm species and their adaptation strategies
in order to develop environmentally safe stategies that
prevent the algal colonization. A plastic waste bin on which
diverse algal morphotypes developed that differed in
structures with presumable functions for cell adhesion or
protection
against
dessication.
Using
rDNA
cloning/sequencing and cultures a total of nine different
phylotypes which belonged to the green algal class
Trebouxiophyceae and the filamentous Klebsormidium
(Streptophyta) were found. The Apatococcus morphotype
with packages of thick-walled cells and a cover of
sporangial wall remnants was most dominant at the studied
site, but ITS rDNA sequence analyses revealed three
different phylotypes of which one could be isolated into
pure culture where it even formed zoospores. Two other
closely related phylotypes represented species that formed
large amounts of mucilage in culture, i.e. Pabia signiensis
and a so far undescribed species of Radiococcaceae
(Trebouxiophyceae). Two other morphologically rather
similar biofilm algae, Chlorella luteoviridis and C.
trebouxioides, did not exhibit particular structures
presumably involved in adaption to the habitat. Because
they are phylogenetically rather distant from one another
and from the type of Chlorella, C. vulgaris, they need to be
assigned to two new genera. Cell walls and mucilage
formation were also studied by electron microscopy.
P07: 4
Molecular phylogeny and systematics of the
"Chroomonas" clade (Cryptophyceae)
Hoef-Emden K.
Universität zu Köln, Botanisches Institut, Germany;
[email protected]
Each cryptophyte culture produces only one of seven
known types of Cr-phycobiliproteins. The four blue
phycobiliproteins are termed phycocyanins although all
cryptophyte phycobiliproteins originate from red algal
phycoerythrin. In the "Chroomonas" clade (including the
genera Hemiselmis and Komma) three types of
"phycocyanins" and one type of phycoerythrin are found,
thus this clade expresses the highest degree of variability of
phycobiliproteins throughout all cryptophyte clades.
To examine the evolution of phycobiliproteins in the
"Chroomonas" clade in greater detail, the absorption
spectra of the phycobiliproteins of phycocyanin-bearing
cultures and of Hemiselmis cultures were determined. In
phylogenies inferred from combined data sets of nuclear
SSU rDNA, partial nuclear LSU rDNA and nucleomorph
SSU rDNA, the genus Hemiselmis was nested in the genus
Chroomonas. Most phycobiliprotein types were not
monophyletic. The evolution of phycobiliprotein types,
geographic distribution of the strains and systematics in this
clade will be discussed.
P07: 5
Peter Kornmann's legacy: Studies of life history in
green algae (Chlorophyta) reveal their taxonomic
status.
Pröschold T.
Culture Collection of Algae and Protozoa, Great Britain
(United Kingdom); [email protected]
Green algae were traditionally classified in orders resp.
classes according to the morphological species concept (i.e.
morphology and cytology of the vegetative stage). For
example, monadoid species (flagellates) are summarized in
the order Volvocales, coccoids in the Chlorococcales,
filaments in Ulotrichales or Chaetophorales, and
siphonocladous algae in Cladophorales or Siphonocladales.
Over more than 60 years Peter Kornmann studied the life
histories of marine seaweeds (green, brown and red algae)
in culture. His studies on green algae in particular resulted
in many changes in systematics and taxonomy of these
algae. For example, he concluded that all green algae,
which have a "Codiolum"-stage in their life cycle, are
closely related independently of their morphology.
Subsequently, phylogenetic analyses have confirmed the
monophyletic nature of this group of green algae. In
addition, the usage of polyphasic approaches (e.g.
secondary structures of SSU and ITS rDNA sequences,
results of crossing experiments, sporangium autolysin data
and studies of life cycles, multigene approaches, AFLP)
advocates a new classification of green algae. New generic
and species concepts (Z- and CBC-clade concepts,
biological species concept, phylogenetic concepts) can be
designed for many orders and most of the classes in the
Viridiplantae on the basis of this approach.
P07: 6
Tracing the evolution of dinoflagellates by analysis of
secondary structural in the LSU ribosomal RNA
Murray S.1 and Moore R.2
1
University of Sydney, Australia; 2University of Adelaide,
Australia; [email protected]
Despite many studies, the phylogeny of dinoflagellates, a
group of intriguing protists, remains unresolved. The large
subunit ribosomal RNA (LSU rRNA), which consists of a
conserved core and 12-13 variable expansion segments
(D1-D12), has often been sequenced in molecular studies
of dinoflagellates. While aligning sequences of the D2
region from a group of closely related dinoflagellates, an
indel with precise boundaries was found situated close to a
site for rRNA cleavage, previously recognised as a “hidden
break”. To determine the distribution and phylogenetic
significance of the indel amongst dinoflagellates, we
determined a general secondary structure model of the D1D3 region, and used this to align the main genera of the
GPP
complex
(Gymnodiniales,
Peridiniales,
Prorocentrales) and the Suessiales. Contrary to previous
results, phylogenetic analyses based on this structural
alignment and taking into account unique base pairing
features of ribosomal RNA found several of the main
orders of dinoflagellates to be each monophyletic.
POSTER ABSTRACTS
21
P08
P08: GENETICALLY
MODIFIED CROP PLANTS
P08: 1
Activation tagging in aspen using an inducible twocomponent Ac/Ds enhancer element system
EL-SHERIF F., HÖNICKA H. and FLADUNG M.
BHF, InstitutInstitute for Forest Genetics and Forest Tree
Breeding, Sieker; [email protected]
Based on the Ac/Ds two element transposition system from
maize an activation tagging approach is suggested for the
hybrid aspen (Populus tremula x tremuloides) line ‘Esch5’.
The proposed approach is based on results obtained from
our earlier work on the genetic transfer of the maize
transposable element Ac and its functional analysis in
hybrid and pure aspen lines. It was shown that the Ac
element is active in aspen. However, a two element
transposon tagging system where the Ds element and the
transposase gene are put together in crosses is not feasible
in trees due to the in part long vegetative phases. To
overcome this barrier, an inducible two element
transposase/ATDs element system is suggested to induce
activation tagged variants following two independent
transformation steps. In combination with a 35S enhancer
tetramer and outward facing two CaMV 35S promoter
located near both ends of the ATDs element, expression of
genes can be elevated which are located adjacent to the new
integration site of the element. The current stage of the
research is as following: (a) The constructs are available
and transgenic aspen have been produced (b) PCR and RTPCR experiments have been conducted to confirm
transformation and induced transposase expression (d) A
number of double transgenic aspen carrying both the Ds
element and the transposase gene have already been
produced.
P08: 3
Ballistic bombardment allows transient co-expression to
100%
Pohanke J., Saleh L. and Plieth C.
ZBM, Christian-Albrechts-Universität Kiel, Germany;
[email protected]
Ballistic micro-projectile bombardment is widely used for
transient protein expression in plant cells. The efficiency of
this transformation procedure often varies. In order to
easily distinguish transfected cells from unaffected ones
within a bombarded specimen, a fluorescent reporter
protein can be co-expressed. However, the expression of
the reporter does not necessarily report the expression of
the target gene and vice versa, the absence of fluorescence
in a cell is not necessarily equivalent to the absence of the
co-bombarded target gene.
We assumed that the percentage of co-expression within
the lot of transgenic cells depends on the molar ratio of
both constructs. In order to verify this hypothesis we used
constructs for expression of a green fluorescent protein
(PtGFP) and a red fluorescent protein (dsRed) targeted to
peroxisomes and to the cytosol, respectively, under the
control of a single CaMV 35S-promoter. We bombarded
gold particles coated with different molar ratios of both
reporter constructs into leek epidermal cells and evaluated
the numbers of red, of green and of red/green fluorescent
cells.
Co-expression occurs within a very broad range of molar
ratios (-3 < log(ratio) < 3). The co-expression is 100%
when the ratio is within 0.3 < ratio < 3. Since, the
expression level also depends on the total amount of DNA
shot into a cell, we started to employ fluorescence ratio
imaging to quantify expression ratio in relation to molar
ratio.
P08: 4
P08: 2
Analysis of a wheat protease inhibitor as a potential
allergen causing baker’s asthma
Manavski N.1, Bittner C.2, Baur X.2 and Wienand U.1
1
Biozentrum Klein Flottbek und Botanischer Garten,
Universität Hamburg; 2Zentralinstitut für Arbeitsmedizin,
Universitätsklinikum Hamburg-Eppendorf;
[email protected]
Baker’s asthma is a serious disease among workers in the
bakery industry and is mainly caused by inhalation of
wheat flour. Although many wheat allergens have been
described recently, reagents currently available are still
unreliable for a secure diagnosis. Therefore large scale
identification and characterization of major wheat allergens
is a prerequisite for development of improved diagnosis
reagents. In this study, the allergenic potential and the
significance of posttranslational modification of the
recently discovered wheat allergen WSCI (wheat
subtilisin/chymotrypsin inhibitor) were analysed. Highly
pure recombinant WSCI isolated from E. coli was obtained
in high yield by affinity chromatography and used in a CAP
IgE assay with sera of wheat-sensitised patients. Partially
strong reactivity of WSCI observed in this assay confirmed
the allergenic potential of the protein. To investigate the
allergenic relevance of posttranslational modification N.
tabacum was transformed by a T-DNA construct
22
containing WSCI-cDNA. Several transgenic N. tabacum
plants were generated. Isolation and purification of the
plant WSCI is currently performed.
POSTER ABSTRACTS
D1-mediated expression of foreign proteins in
chloroplasts
Fischer D. and Johanningmeier U.
Martin-Luther-Universität Halle, Germany;
[email protected]
The D1 protein as a central component of the PSII complex
is encoded by the psbA gene located on the chloroplast
genome. It is synthesized as a precursor protein with a Cterminal extension, which is cleaved off by the processing
protease CtpA and released into the chloroplast lumen. The
extension sequence is very diverse among the different
organisms and its absence does not significantly affect the
function of the protein. In Chlamydomonas reinhardtii the
D1 precursor has an extension of 8 amino acid residues.
We have started to analyse the possibility of a D1-mediated
expression of foreign proteins/peptides attached to the
extension sequence. This approach should allow us to
express light regulated “cut-to-size” polypeptides in
plastids. Moreover, since the D1 protein has a fast turnover
in the light and is therefore synthesized in high amounts, it
should
be
possible
to
overaccumulate
stable
proteins/peptides by controlling light intensities. Finally,
transgenic photosynthetic algae can be obtained by
selection for autotrophic growth. Since no resistance genes
are involved, this represents an antibiotic free transgenic
approach.
P08
P08: 5
Elimination of Marker Genes and Targeted Integration
of Transgenes via the FLP/FRT-Recombination System
Schenk T.1, Fladung M.2, Lörz H.1 and Becker D.1
1
University of Hamburg, Germany; 2Federal Research
Centre for Forestry and Forest Products, Großhansdorf;
[email protected]
The marker gene elimination in transgenic plants will be
investigated in wheat (Triticum aestivum) and poplar
(Populus spec.) using the FLP/FRT recombination system.
The construct contains the FLP-recombinase under control
of a heat inducible promoter, the antibiotic resistance gene
(npt-II) driven by CaMV35s promoter and a promoterless
gus gene. The constructs will be integrated into common
wheat (Triticum aestivum L.) and poplar (Populus spec.)
via biolistic transformation and Agrobacterium mediated
transformation, respectively. The active recombinase FLP
will cut the npt II markergene and combines the
promoterless gus gene with the CaMV35s promoter to form
an active gus gene.
For analyzing transgene integration in the plants tested, two
constructs will be used. One carries the inducible FLP and
the npt-II gene, the other contains the promoterless
selection marker bar flanked with FRT-sites. After
transformation and induction of FLP, the enzyme will
arrange a homologue recombination at the FRT-sites of
both constructs and rebuild the selection marker genes
under promoter control.
The expected results form a promising basis for the
production of antibiotic-free transgenic plants. This
becomes more and more important for future field trials in
the EU, which prohibit releasing transgenic plants
containing antibiotic markers.
coding for resident defense metabolites to elucidate the
nature of their interaction in transgenic lines.
P08: 7
GMO Monitoring
Boettinger P.1, Schmidt K.2, Wilhelm R.1, Schmidtke J.2
and Schiemann J.1
1
Biologische Bundesanstalt Braunschweig, Germany;
2
BioMath Rostock, Germany; [email protected]
While research and development in plant biotechnology is
going on, the notification and placing on the market of
genetically modified plants (GMPs) is still complicated.
According to EU Directive 2001/18/EU, monitoring is a
statutory requirement for the cultivation of GM crops in the
EC. This comprises case specific monitoring to investigate
distinct hypotheses about potential adverse effects
identified in the environmental risk assessment, and general
surveillance to detect unpredictable adverse effects.
Significant deviation from standard values, from "what is
common" should be identified and trends and tendencies
should be traced by further investigation.Data collection by
farmers can form a useful part of a monitoring regime,
while adverse effects will first emerge (if at all) on areas
under cultivation and/or in close relationship to them.
Farmers are the closest observers of acreage and crops, they
collect information on cultivation and crop management,
and they can give details from field-specific records e.g.
soil analysis, yields, pest dynamics, etc. providing
information about monitoring parameters and influencing
factors. A sophisticated survey design and strong statistical
analysis is necessary for sound data. Advantages and
constraints of this method will be adressed and examples
from Bt and Ht Maize monitoring by means of a scientific
survey will be presented.
P08: 6
Genetic Transformation of Kenyan Sorghum (Sorghum
bicolor L. Moench) with Chitinase and Chitosanase for
Fungal Disease Resistance
Ayoo L., Bader M., Becker D. and Lörz H.
Sorghum (Sorghum bicolor L. Moench) ranks fifth,
worldwide in production among cereals. Plant diseases
reduce world food production by more than 10%. Fungal
diseases of sorghum, such as anthracnose (caused by
Colletotrichum sublineolum ), cause substantial worldwide
losses. Disrupting the synthesis or integrity of fungal cell
wall by host plant’s defense system, affords a disease
tolerance strategy. Pathogenesis related proteins such as
chitinases, cleave cell wall chitin polymers. Chitosanases
hydrolyse the ß-1,4-linkages in chitosan, another fungal
cell wall component. Sorghum was biolistically
transformed with a chitinase (chi) and a chitosanase (Cho)
cDNA from Trichoderma harzianum. Both genes were
consitituvely coexpressed under the control of the
ubiquitine (ubi) promoter from maize. Inheritance and
expression of the introduced traits was studied in T1 and T2
transgenic sorghum lines to ascertain stable and functional
transgene integration. In vitro and in vivo C. sublineolum
infection assays with leaf segments and seedlings were
carried out to determine the level of tolerance to C.
sublineolum. Finally, expression of the introduced genes
was compared with naturally occurring chalcone synthaselike gene (SbCTS1) and a sorghum chitinase gene (ChitV) ,
P08: 8
Optimization of the Moss Bioreactor: Effects of cell wall
loosening
Büttner-Mainik A., Reski R. and Decker E.
Universtität Freiburg, Germany;
[email protected]
The Moss (Physcomitrella patens) Bioreactor is
increasingly being used to produce recombinant
biopharmaceuticals.
Besides
efficient
homologous
recombination and highly controllable photoautotrophic
growth this system benefits from secretion of proteins into
a simple inorganic liquid medium, greatly facilitating
downstream processing. The moss cell wall consists of a
complex network of stiff cellulose microfibrils embedded
in a soft amorphous matrix of hemicelluloses, pectins and
structural proteins. Whereas small, simple proteins can pass
this barrier easily, secretion of bigger proteins decorated
with complex posttranslational modifications may be
hampered. Therefore, we aim at loosening the moss cell
wall in a controlled way. We have analysed the
Physcomitrella expansin family, as these proteins are
involved in cell wall loosening. We will report on our
results about expression, intracellular localisation and
effects of ectopic overexpression of one of these expansins
under control of an inducible promoter.
Funding by the FCI (Foundation of the Chemical Industry)
and by BMBF (German Federal Ministry of Education and
Research; grant No. 31P4109) is gratefully acknowledged.
POSTER ABSTRACTS
23
P08/P09
P08: 9
Over-expression of a V. faba amino acid permease in
developing seeds of transgenic pea (Pisum sativum)
changes protein metabolism
Weigelt K.1, Küster H.2, Götz K.3, Saalbach I.1 and
Weber H.1
1
Leibniz Institute of Plant Genetics and Crop Plant
Research, Gatersleben; 2CeBiTec - Center for
Biotechnology, Bielefeld University, Germany;
3
Pflanzenbau in Tropen und Subtropen, Humboldt
University Berlin, Germany; [email protected]
Synthesis of storage protein is regulated at different levels
during seed maturation. The availability and distribution of
assimilates and nitrogen compounds are mostly important.
During seed growth, sugar and nitrogen compounds confer
regulatory control on storage activities. Thus, seed storage
production could be regulated by the supply of nutrients. In
order to improve nitrogen flux into the embryo, the V. faba
amino acid permease VfAAP1 was expressed in pea under
the control of the embryo-specific LeB4 promotor. Several
transgenic lines have been generated. We applied cotransformation with the selectable marker on a separate
plasmid. This enabled to remove the marker gene by
segregation. Northern analysis revealed over-expression of
VfAAP1. Mature seeds of the homozygous marker genefree line AAP14/10 showed higher protein concentration
over 5 generations due to an increased globulin fraction.
The effect of VfAAP1 was tested under field conditions in
two growing periods and the data could be confirmed. We
conclude that over-expression of VfAAP1 interferes with
storage protein metabolism and alters fluxes of nitrogen
during seed growth. In further analysis we test the influence
of VfAAP1 on altered gene expression in developing
cotyledons using cDNA-microarrays containing app. 6,000
genes from pea seeds. Furthermore we are comparing
amino acid composition in growing seeds as well as
assimilate partitioning on the whole plant level.
P08: 10
Transfer of microbial genes for the synthesis of the
compatible solute glucosylglycerol into plants
Klähn S.1, Marquardt D.2, Ribbeck-Busch K.1, Marin
K.2 and Hagemann M.1
1
University of Rostock, Germany; 2University of Cologne,
Many organisms accumulate compatible solutes under
environmental stress conditions, e.g. the heteroside 2-O-(αD-glucopyranosyl)-glycerol (GG). GG is accumulated by
moderate halotolerant cyanobacteria and a few
heterotrophic bacteria. It mediates salt stress tolerance as
well as the protection of proteins and membranes during
denaturing conditions. Therefore it seems promising to
transfer GG-synthesizing enzymes into sensitive organisms
such as plants. In first experiments potato plants were
transformed with the genes ggpS (GGP-synthase) and stpA
(GGP-phosphatase) from the cyanobacterium Synechocystis
sp. strain PCC 6803. In fact the potato plants were able to
synthesize and accumulate low amounts of GG (< 0.7
µmol/g FM), which were not adequate to increase plant
stress tolerance. Possibly limiting concentration of the
precursor ADP-glucose in plant cells was responsible for
the low levels. Recently, we characterized new GGforming enzymes in the heterotrophic bacteria Azotobacter
vinelandii and Stenotrophomonas rhizophila. These present
fusion proteins exhibiting both, synthase and phosphatase
24
POSTER ABSTRACTS
activity and depend on UDP-glucose. These features made
it promising to transfer these genes into the model plant
Arabidopsis thaliana.
P08: 11
Wheat (Triticum aestivum) genetic trnsformation to get
Fusarium graminearum resistance.
Ahmad R.1, Becker D.1, Salomon S.2, Schäffer W.2 and
Lörz H.1
1
Department of Developmental Biology and Biotecnology,
University of Hamburg; 2Department of Molecular
Phytopathology and Genetics, University of Hamburg;
[email protected]
A resistance criterion for fungal diseases is accomplished
by two types of genes i) that modify plant physically in
such a way that plant lets not the Fungus penetrate, ii) Anti
fungal genes, coding proteins that degrade fungal cell wall,
disorganize fungal membranes or interfere with fungal
protein synthesis. Here we present two methods those may
cause higher fungal resistance in trangenic wheat.
Callose (1,3-ß-glucan) is supposed to offer physical
resistance for fungal pathogen to penetrate into plant cell
wall (Stone and Clarke, 1992). In wheat, an eight member
callose gene family called Glucan synthase like genes
(homologous to yeast FKS genes, controlling callose
production) is identified. It was decided to identify the
exact function of three of its members using Post
Transcriptional Gene Silencing. Effect of these genes on
callose content and activity will be seen and later on, the
effects do it has on resistance to Fusarium graminearum.
Depending upon the results a future stretegy will be
inferred to answer the question to produce resistant wheat.
Chitinase and Chitosanase are the enzymes those hydrolyse
Chitin and Chitosan respectively which are the major
components of fungal cell wall. Although their substrates
are absent in plants but their genes are differentially
expressed under pathogen attack and physical stresses. It
was decided to over express these from Trichoderma
harzianum into wheat to see the effect of over expressed
chitinase and chitosanase proteins against Fusarium
pathogen.
P09: GRAVITATION
BIOLOGY
P09: 1
Endocytosis and Vesicle Trafficking in Gravitropism
and Phototropism
Wan Y.1, Kubitscheck U.2, Volkmann D.1 and Baluška
F.1
1
Institut für Zelluläre und Molekulare Botanik (IZMB),
Universität Bonn; 2Institut für Physikalische und
Theoretische Chemie, Universität Bonn;
[email protected]
Phototropin 1 (phot1) is the essential photoreceptor for
phototropism, chloroplast and stomata movements, leaf
expansion, and likely also the solar tracking in response to
blue light. Following earlier work with PHOT1::GFP
(Sakamoto and Briggs, 2002, Plant Cell 14, 1723-1735), we
have investigated patterns of cellular and subcellular
localizations of phot1 in cells of etiolated seedlings of
Arabidopsis thaliana. The blue light initiates endosomal
recycling of PHOT1. Our data reveal that speed and rate of
the PHOT1 internalization reflects the intensity of blue
P10/P11
light illumination. Brefeldin A (BFA), the inhibitor of
endosomal recycling, inhibits blue-light induced root
phototropism as well as the endocytic recycling of PHOT1
by trapping it within BFA-induced endosomal
compartments. The size of these compartments reflects the
intensity of blue light illumination. The formation of BFAinduced compartments can be inhibited by pre-treatments
of seedlings with latrunculin B and wortmannin. All this
suggest that F-actin and PI(3)K dependent endosomal
recycling of PHOT1 is part of the blue-light signalling
cascade in plant cells.
P10: HALOPHYTES
P10: 1
Halophytic vegetation of the Dominican Republic and
their ecophysiological adaptations
Sánchez R.1, Bonilla O.2, Hager J.3, Veste M.4 and
Breckle S.3
1
Consorcio Ambiental Dominicano (CAD), Dominican
Repbulic; 2Universidade Estadual do Ceará, Brazil;
3
University of Bielefeld, Germany; 4University of
Hohenheim, Germany; [email protected]
Halophytic vegetation occurs in the Dominican Republic
along the coast, oncoastal dunes, in the mangroves and
along inland salt lake. Typical plantspecies of the coastal
saline habitats are e.g Cakile lanceolata, Ipomoeapescaprae, Sesuvium portulacastrum, Blutoperon verniculare,
Heliotropium
curassavicum.
Rhizopohora
mangle,
Laguncularia
racemosa,
Avicenniagerminans
andConocarpus erectus and the mangrove ferns
Acrostichumaureum and A. danaefolium occurs in the
mangrove swamps. Regarding the salinity the inland lake
Lago Enriquillo is one of the most extreme habitat (salt
concentration up to 7.1%). Along its shores e.g. Batis
maritima, Sesuvium portulacastrum and Salicornia perennis
can be found. The salt tolerance and ecophysiologcial
adaptations of different populations of the mangrove fern
A. danaefolium and the coastal halopyhes B. maritima and
S. portulacastrum were investigated. The distinct
accumulation of NaCl in the roots of A. danaefolium can be
interpretated as a major strategy to prevent toxic salt effects
in the leaves and can the mangrove fern can be
characterzied as a pseudohalophyte. B. maritima and S.
portulacastrum aretypical halo-succulents.
P10: 2
The use of halophytes for rehabilitation of salt effected
soils in northeast Brazil
Bonilla O.1, Major I.1, de Oliveira Martins M.1 and
Veste M.2
1
Universidade Estadual do Ceará, Brazil; 2University of
Hohenheim, Stuttgart, Germany; [email protected]
In drylands salinity is often very prominent, caused by the
input of sodium chloride and other salts and the lack of
drainage In this environment the excesses of soluble salts in
the soils have a large influence on the ecosystems and
productivity in extensive areas. Halophytes may serve to
improve the ecosystem production. They are model plants
for the understanding of the adaptation strategies in such
habitats. Aim of the presented study was to identify suitable
plants for their reestablishment on saline soils in the region.
The survey included 23 common species from 8 families.
Samples were collected in the rainy and dry season in a
period of three years. The cations Na+, K+, Ca2+ and Mg+
were analysed. Great variations of salt content among the
plants could be found and highest content of sodium and
chloride were found in Sesuvium portulacastrum
(Aizoaceae) and Blutaparon vermiculares (Amarantaceae).
It was also verified, that most of those plants are able to
growth on degraded saline soils and they are possible
candidates for the rehabilitate degraded soils.
P10: 3
Ecophysiology and usability of xero- and halophytes at
dry and saline habitats: Learning by studying the
experts
Koyro H., Geissler N. and Hussin S.
Institute for Plant Ecology, Germany; [email protected]
Environmental abiotic stress conditions, and especially
drought and salinity, are currently the major factors which
reduce crop yields world-wide. One way to supply the
demand is to develop sustainable biological production
systems which can tolerate higher water salinity. The
sustainable use of halophytic plants is a promising
approach to valorize strongly salinised zones unsuitable for
conventional agriculture and mediocre waters. Halophytes
include a large taxonomic variety and occupy diverse
habitats, from extreme dry to temporarily waterlogged sites
or salt marshes. The development of cash crop halophytes
and the breeding of salt resistant crop varieties will require
a clear understanding of the complex mechanisms of salt
stress tolerance, which we are still lacking despite intensive
research during the last decade. Salinity can affect any
process in the plant's life cycle, so that tolerance will
involve a complex interplay of characters. Research
projects investigated details of the physiology and
biochemistry of salt tolerance and also searched for
methods to screen overall plant performance that could be
used in breeding programmes. Considering the complexity
of the mechanisms of salt tolerance, it seems worthwhile to
compare the responses to salt stress in plants with different
levels of tolerance. This approach may help to establish
which of the observed responses are general and essential
for salt tolerance, and which are not.
P11: HISTORY OF BOTANY
P11: 1
History of vegetation’s research in Siberia: 18th century
scientists’ contribution
Zvjaghina N.
Central Siberian botanical garden, Russian Federation;
[email protected]
Nature of Siberia remained as “terra nova” until the
beginning of 18th century. Professor of medicine D. G.
Messerschmidt was the first who started to search unique
Siberia nature, its aboriginal population culture and
language, local climate, etc. in 1721. It must be difficult to
overestimate his scientific heritage: he discovered more
than 380 unknown high vascular plant species. Naturalist,
professor J. Gmelin was invited to work in Russia in 1727
and several years later he was a participant the 2nd
Kamchatka expedition which lasted 10 years. The Gmelin’s
outstanding 4 volumes book “Flora Rossica” based on his
investigations in Siberia includes descriptions of 1178 plant
species and 294 illustrates. His and Messerschmidt’s
herbarium collections are partly kept in Stuttgart, Germany.
Substantial studies has also been carried out by count
POSTER ABSTRACTS
25
P11/P12
Waldburg-Zeil whose 340 species herbarium collection was
taken as a basis of Karl Fritz’s “Aufzählung der von K.
Graf von Waldburg-Zeil im Jahre 1876 in Westsibirien
gesammelten Pflanzen” (1879). My work is geared towards
the flora of Kuznetskaja depression which is situated in the
south-west of Siberia. Kuznetskaja depression forest –
steppe landscapes have been suffering from urbanization
and destructions caused by rapid development coal industry
for the last decades. Therefore modern floristic researches
focus on both the native and spoilt floras of the region as
well. I expect that comparing 18th century investigators
and the latest contemporary floristic attainments would
discover tempting results about Kuznetskaja depression
flora evolution.
P11: 2
vifabio – Aggregating Library and Internet Resources
for Biologists
Kasperek G., Dähne J., Rexhepi J. and Dugall B.
University Library Frankfurt, Germany;
[email protected]
The Virtual Library of Biology – vifabio – has been
established as a central library portal. This ongoing project
is conducted by the University Library Johann Christian
Senckenberg, Frankfurt/Main, with several partner
institutions in Germany and Austria. The project’s
objective is to create a single point of access to various
resources for biologists, such as printed materials in
libraries, databases and internet sites. The core elements of
vifabio are:
(1) A meta-catalogue (virtual catalogue) where multiple
libraries with important holdings of biological literature are
integrated for parallel search.
(2) In cooperation with Kurt Stübers BioLib, digitised
versions of historic biology books are now available as
Portable Document Files.
(3) The Internet Guide is a collection of quality-checked
links to biological internet resources. Access is provided
via search tools, as well as via browsing through multiple
alternative systems of resource arrangement.
(4) An inventory of important online databases provides
access via searching and browsing: bibliographical
databases as well as factual and pictorial databases in all
sub-disciplines of biology; most of them freely accessible.
DFG-funded licences permit nationwide usage of some
bibliographic databases, for example, Biological Abstracts
1926-2004.
Access on electronic journals is enabled through the
Electronic Journals Library (EZB). Further enhancements
of vifabio will include improved linking features to
electronic full-texts as well as integration of bibliographic
databases into the meta-catalogue.
P12: LICHENS
P12: 1
EFFECT OF STRESS AND CULTURAL
CONDITIONS ON LICHEN PHYCOBIONTS:
ULTRASTRUCTURAL ALTERATIONS
Vlasova T.
Dept. of Plant Physiolgy, Fac. of Biology, Moscow State
University; [email protected]
26
POSTER ABSTRACTS
The ultrastructural features in the green unicellular alga
Coccomyxa, phycobiont of the foliose lichen Peltigera
aphthosa, in the lichen thalli in the different conditions as
well as in the isolated cultures of Coccomyxa in the
different nutrient media were compared. Isolated algal
cells underwent the obvious ultrastructural alterations
which demonstrated the changes in the specificities of the
cell metabolism. The experiments with the green
unicellular alga Trebouxia, phycobiont of the foliose lichen
Hypogymnia physodes, demonstrated similar results. The
prolonged action of the unfavorable storage conditions on
the thalli of P. aphthosa led to the pronounced
ultrastructural alterations in the cells of both mycobiont and
phycobiont (cell destruction and disjunction of symbionts,
i.e. delichenisation) showing the certain degradation of
both symbionts. Within definite time limits the degradation
was reversible: the symbiont cell structure and accordingly
their functions could be reestablished by transferring to the
more favorable conditions. The phycobiont recovered more
quickly than the mycobiont; it supposed the dominant role
of the photobiont as energy supplier. However, the
prolonged action of unfavorable conditions led to the
irreversible cell destruction and finally to the degradation
and death of the whole thalli. Some of the observed
ultrastructural changes in the cells of the green phycobionts
indicating their functional changes may be estimated as the
adaptive reorganizations.
P12: 2
Phylogeny of the genera of Parmeliaceae (Lichenes)
visualized by pictographs
Feuerer T.1 and Thell A.2
1
Biozentrum Klein Flottbek, Germany; 2Lund University,
Sweden; [email protected]
The largest family of lichens, the Parmeliaceae, comprises
about 2600 species of macrolichens, arranged in 78 genera.
Whereas 18 genera were accepted in 1974 by Henssen &
Jahns, the number was risen to 92 some years ago. Their
phylogenetic relationship was subject of intense molecular
investigations in recent years. It is expected that the present
number of genera will further be reduced until a
stabilization will be reached at about 60 genera.
Melanelixia, Melanohalea and Davidgallowaya have been
added in the last years. The description of new genera will
not fully compensate the decrease in other cases. When
discussing the results of molecular investigations on the
phylogenetic position of the genera, it is useful to visualize
the structural descriptors, i.e. the anatomical and
morphological characters and their states, common to the
groups in question and decisive for their circumscription.
Whereas flower diagrams are permanently used to visualize
relationships between angiosperm taxa, no adequate
method was available for lichens up to now. We present a
useful scheme how to construct pictographs which
comprise standard characters like growth form, attachment
organs, soralia, isidia, cilia, fruiting bodies, anatomical
characters and others, typical for species or genera.
Alltogether more than 40 characters with a variety of states
are depicted in our example.
P13
P13: MEMBRANE
TRANSPORT
P13: 1
Paralia sulcata: new insights into its ecological role
Gebühr C.1, van Beusekom J.2, Aberle-Malzahn N.1 and
Wiltshire K.1
1
BAH - Alfred-Wegener-Institute, Helgoland, Germany;
2
Wadden Sea Station, Alfred-Wegener-Institute, Sylt,
Microalgae and especially diatoms form the basis of the
marine food web and are the main primary producers in the
world ocean. Paralia sulcata is a cosmopolitan brackish to
marine tychopelagic diatom species which is common in
the benthos and in the pelagic during winter around the
islands Helgoland and Sylt, North Sea. P. sulcata lives
under a wide range of environmental conditions like the
Wadden Sea and offshore waters, but not much is known
about its ecology. Due to the fact that P. sulcata appears in
the sediment and in the water column throughout the year,
this diatom probably plays an important role as food source
for benthic and pelagic grazers.In this study P. sulcata were
isolated from Wadden Sea sediments on Sylt and from
phytoplankton at Helgoland Roads. They were cultivated
under different light and nutrient conditions with and
without sediment and turbulence. We will present first
results of experiments on bentho-pelagic coupling
mechanisms of P. sulcata. The physiological reaction of P.
sulcata to different conditions was determined using
pigment analyses, CHN-analyses, fatty acid analyses and
via the growth rates and photosynthetic activity. These
results will be placed into a greater context by comparing
them with results from the Helgoland Roads long-term data
series and the Sylt long term series with an emphasis on
succession patterns and the ecological behaviour of P.
sulcata in the field.
P13: 2
Phloem loading revisited: Companion cells do the job
Schmitt B., Stadler R. and Sauer N.
Molecular Plant Pysiology, University of Erlangen,
Apoplastic phloem loading generates an intracellular
osmotic driving force that provides the basis for the mass
flow within the vasculature of higher plants. The loading
step is mediated by transporters in the plasma membrane of
highly specialized sieve elements (SE) or companion cells
(CC) of the phloem. Since several years it has been
discussed controversially which of these two cell types is
responsible for this and essential function. Evidence for a
localization of sucrose transporters in different cells (SE or
CC) in different plant species has been provided. In
solanaceous plants, sucrose transport proteins (SUT1) were
immunolocalized to the plasma membranes of enucleated
SEs. In contrast, in Arabidopsis thaliana or Plantago major
sucrose loading into the phloem was shown to be mediated
by CC-localized sucrose transport proteins (AtSUC2 and
PmSUC2) and no other sucrose transporter was identified
in the CCs of the plants.Due to the discrepancy between
these data sets we decided to perform independent
immunolocalization analyses of the localization of
solanaceous SUT1 proteins. Here we present data on the
localization of LeSUT1, StSUT1 and NtSUT1 in leaf veins
of tomato, potato and tobacco, respectively. In contrast to
previous reports we identified all three proteins specifically
and exclusively in the plasma membranes of the phloem
CC. Also opposite to previous results the localization was
much stronger in the abaxial (external) phloem than in the
adaxial (internal) phloem of all three species.
P13: 3
Cd transport in the hyperaccumulator Thlaspi
caerulescens
Leitenmaier B.1, Parameswaran A.1, Yang M.1 and
Küpper H.1,2
1
Universität Konstanz, Fachbereich Biologie, Konstanz,
Germany; 2University of South Bohemia, České
Budejovice, Czech Republic; [email protected]
Hyperaccumulators can not only tolerate high amounts of a
specific metal, they are even able to take it up actively up
to several percent of the dry weight of their aboveground
parts. This feature makes them interesting for the cleaning
of polluted soils (phytoremediation) or for the so called
phytomining, a process which uses plants grown on metal
contaminated soil to extract the raw metal out of the ash of
those plants. To learn more about the mechanisms behind
hyperaccumulation, it is crucial to find out more about the
transport and root-to-shoot translocation of the accumulated
metal(s).
In this project, first the uptake of cadmium into protoplasts
isolated from T. caerulescens was investigated using a
fluorescence kinetic microscope and a fluorescent dye
specific for Cd2+. The results showed that the transport over
the vacuolar membrane is the time limiting step in
cadmium uptake. Higher Cd uptake rates into large
compared to smaller epidermal protoplasts and protoplasts
from the mesophyll further demonstrated that the
differences in metal accumulation in these cells are at least
partially caused by differences in cytoplasmic uptake.
Further, TcHMA4, a P-type ATPase that transports zinc as
well as cadmium over the cytoplasmic membrane, was
isolated from roots of T. caerulescens grown on 100 µM
Zn2+. It was found that the natural form of this transporter
is modified by post-translational processing. Activity tests
of the purified protein showed that it is in its active state
and its activity can be strongly increased by the addition of
metal during the activity test.
P13: 4
Channelrhodopsins: Characterization and Applications
Nagel G.1,2, Looser J.1, Szellas T.2, Bamberg E.2 and
Hegemann P.3
1
University Wuerzburg, Germany; 2Max-Planck-Institute of
Biophysics, Frankfurt/M., Germany; 3Humboldt University,
Berlin, Germany; [email protected]
Phototaxis of the green alga Chlamydomonas reinhardtii is
mediated by rhodopsins with microbial-type chromophores.
cDNA sequences in Chlamydomonas reinhardtii, which we
termed Channelopsins (Chop), show homology to the lightactivated proton pump bacteriorhodopsin. Expression of
Chop-1 in Xenopus laevis oocytes produces a light-gated
conductance. The chromo-protein Channelrhodopsin-1
(ChR1 = Chop1 + retinal) shows characteristics of a lightsensitive channel, selectively permeable for protons.
Also Channelrhodopsin-2 (ChR2) is an ion channel, which
is directly switched by light. Channelrhodopsin-2 is a lightgated non-selective Cation Channel, permeable to many
POSTER ABSTRACTS
27
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monovalent (H+ > Li+ > Na+ > K+ > Cs+) and to some
divalent (Ca2+, Sr2+, Ba2+, but not Mg2+) cations. The action
spectrum of ChR2 is blueshifted with respect to ChR1. We
suggest that Channelrhodopsins are involved in phototaxis
of green algae.
Heterologous expression of Channelopsins is useful to
manipulate intracellular pH, [Ca2+], or membrane potential
of cells, simply by illumination. Recently we and others
demonstrated functional expression of ChR2 in neurons
from different organisms. ChR2 in rat hippocampal neurons
allows reliable triggering of action potentials by blue light
and ChR2 in muscle cells or neurons of live and freely
moving C. elegans enables light-induced behavioral
changes. ChR2 also mediates strong effects of blue light
on living D. melanogaster larvae and currently we are
investigating its effect on transgene A. thaliana.
P13: 5
Co-operation of anion transporter CLC-d and VATPase in the trans-Golgi Network
Ludewig U., von der Fecht-Bartenbach J., Bogner M.,
Krebs M., Stierhof Y. and Schumacher K.
ZMBP, Universität Tübingen, Germany;
[email protected]
Anion transporting proteins of the CLC-type are involved
in anion homeostasis in a variety of organisms. CLCs from
Arabidopsis have been shown to participate in nitrate
accumulation and storage. In this study, the physiological
role of the functional chloride transporter AtCLC-d from
Arabidopsis was investigated. AtCLC-d is weakly
expressed in various tissues, including the root. When
transiently expressed as a GFP-fusion in protoplasts, it colocalized with the VHA-a1 subunit of the proton
transporting V-type ATPase in the trans-Golgi network
(TGN). Stable expression in plants showed that colocalized with the endocytic tracer dye FM4-64 in a
Brefeldin A-sensitive compartment. In accordance with
these findings, the TGN was labelled with gold markers,
using immunoelectron microscopy. Disruption of the
AtCLC-d gene by a T-DNA insertion did not affect the
nitrate and chloride contents. The overall morphology of
clcd-1 plants was similar to that of the wild type, but root
growth on synthetic media was impaired. Moreover, the
sensitivity of hypocotyl elongation to Concanamycin A, a
blocker of the V-ATPase, was stronger in clcd-1. These
phenotypes could be complemented by the over-expression
of AtCLC-d in the mutant background. The results suggest
that the luminal pH in the trans-Golgi network is adjusted
by AtCLC-d-mediated transport of a counter anion such as
Cl- or NO3-.
P13: 6
Cyclic nucleotide-gated channels: Complex regulation
or pseudogene
Köhler B., Müller K., Schulz K. and Mueller-Roeber B.
Universität Potsdam, Germany; [email protected]
Cyclic nucleotide-gated channels (CNGCs) are ligandgated non-selective cation channels that provide entry
pathways for K+, Na+ and Ca2+. They play a role pathogen
defense and in plant growth and development. In
Arabidopsis thaliana the gene family comprises 20
members. Here we report news from AtCNGC12. It is
expressed in roots, leaves and flowers. Cloning of the
cDNA resulted in the identification of two different
transcripts. One encodes for a full-length protein, the other
carries a premature stop codon. Heterologous expression in
28
POSTER ABSTRACTS
Xenopus oocytes and a yeast based aequorin system
showed that they are functionally different. Both transcripts
occur in a variety of tissues and under a variety of stresses.
These results indicate that AtCNGC12 is regulated in a
complex way. Interestingly, a regulatory function of
AtCNGC12 but not AtCNGC11 has been postulated by
Yoshioka and colleagues (2006). On the other hand, TDNA insertion lines for AtCNGC12 showed a weak
phenotype and intron-retaining transcripts were detected
regularly. AtCNGC11 and AtCNGC12 result from gene
duplication and are very similar. It can not be ruled out that
AtCNGC12 is about to become a pseudogene - ‘hanging
around’ in the genome. Pros and Cons are
discussed. REFERENCEYoshioka K., Moeder W., Kang
H.G., Kachroo P., Masmoudi K., Berkowitz G., Klessig
D.F. (2006) The chimeric Arabidopsis CYCLIC
NUCLEOTIDE-GATED ION CHANNEL11/12 activates
multiple pathogen resistance responses. Plant Cell 18: 74763
P13: 7
Diffusion Driven GFP Transport Through
Plasmodesmata
Schönknecht G.1,2, Brown J.2 and Verchot-Lubicz J.2
1
Universität Düsseldorf, Germany; 2Oklahoma State
University, USA; [email protected]
Plasmodesmata (Pd) are intercellular channels connecting
neighboring plant cells and provide a pathway for the
exchange of a variety of macromolecules. A method
routinely used to characterize the ability of the green
fluorescent protein (GFP) to move through Pd is to
calculate the percent of sites showing fluorescence moving
into neighboring cells. In this study, leaves bombarded
with plasmids expressing GFP or GFP fused to the viral
movement protein PVX TGBp1 were incubated at various
temperatures and the percent movement was recorded. The
Arrhenius equation was used to describe the temperaturedependence of GFP and GFP-TGBp1 movement between
cells and to calculate the activation energy for transport of
both proteins. The resulting low activation energy
indicates GFP and GFP-TGBp1 movement are diffusion
driven. TGBp1 directed transport of GFP had a higher
frequency of movement than GFP alone, along with
comparably low activation energy. Further experiments
show that GFP movement has a direct relation to leaf
surface area. Since the increase in leaf area is primarily the
result of cell expansion during the sink-source transition,
the increasing cell size means longer diffusion distances for
GFP within each cell to reach Pd. Since diffusion time is
determined by distance, the decline in GFP movement as
leaf area expands is expected for a diffusion driven
process. In summary, this report provides a new simple
quantitative method for studying Pd conductivity.
P13: 8
ER export of the K+ channel KAT1
Mikosch M.1, Reuff M.1, Hurst A.1,2 and Homann U.1
1
TU Darmstadt, Germany; 2University of Queensland,
Australia; [email protected]
The correct functioning of ion channels depends not only
on the control of their activity but also on the regulation of
their number in the plasma membrane which is determined
jointly by the secretory- and endocytic pathways. Previous
investigations on trafficking of the plant K+ channel KAT1
from Arabidopsis thaliana revealed that this channel
underlies a constitutive and pressure-driven turnover (1, 2).
P13
Our recent studies imply that the plasma membrane channel
density can also be adjusted by regulating the export of
KAT1 from the ER (3). Analysis of four di-acidic
DXE/DXD motifs in the cytosolic C-terminus of KAT1
demonstrated that ER export was largely dependent on the
first di-acidic motif. Mutation of this motif resulted in a
strong reduction of the KAT1 conductance in both guard
cell protoplasts and HEK293 cells (human embryonic
kidney cells). Confocal fluorescence microscopy revealed
localization of the mutated channel only in the ER
Mutation of the three other di-acidic motifs had no effect.
Together the results demonstrated that one di-acidc motif is
essential for ER export of KAT1. It also suggests that
trafficking of plant plasma membrane ion channels is
controlled via a conserved mechanism.
Preliminary results indicate that efficient ER export of
KAT1 tetramers does not require ER export motifs of all
four subunits. Formation of heterotetramers may thus affect
targeting of closely related K+ channels.
(1) Hurst et al. (2004) Plant J. 37: 391-397
(2) Meckel et al. (2004) Plant J. 39: 182-193
(3) Mikosch et al (2006) Plant Physiol. 142: 923-930
P13: 9
Exact Biology - An unequivocal (mathematically
airtight) proof for the existence of heteromeric K+
channels in plants
Dreyer I.1 and Lebaudy A.2
1
Universität Potsdam, Germany; 2INRA Montpellier,
France; [email protected]
In 1997 and thereafter it was reported that voltage-gated
plant K+ channel α-subunits have in principle the potential
to form heteromeric channels when co-expressed in
heterologous expression systems. The bunch of data led to
the model that in planta voltage-gated K+ channels may (at
least in part) be heteromultimeric proteins. Also the
characterization of potassium currents in plants revealed
results that were not easily explainable by the existence of
exclusively homomeric K+ channels in vivo. However, an
airtight proof for the existence of heteromeric K+ channels
was still missing. It was awaited to arise at the biochemical
level by the direct purification of heteromeric channels
from plant cells.
Here we choose a different way. We designed a “nonbiochemical” experimental approach based on molecular
biology, generation of transgenic plants and basic plant
physiology that allowed us to proof the existence of
heteromeric K+ channels in plants. The proof is strict and –
in mathematical terms – airtight.
The results of the experiments did not only allow to
unequivocally answer the question “Do heteromeric K+
channels exist in plants?”. They also revealed detailed
insights into certain physiological processes to which plant
K+ channels fundamentally contribute.
P13: 10
Expression of a K+ inward rectifying channel from lily
pollen, LilKT1, in yeast
Lughofer P.1, Bertl A.2, Hude R.1 and Obermeyer G.1
1
University of Salzburg, Austria; 2TU Darmstadt, Germany;
[email protected]
During the germination and the growth of pollen tubes,
endogenous electrical fields are generated that are mainly
carried by in- and effluxes of H+, K+, Cl-, and Ca2+. The
electrical field probably helps to determine the direction of
tube growth and growth rate oscillations. An inward K+
current was observed in protoplasts of pollen grain and
pollen tubes by means of the patch-clamp technique and an
AKT1-like K+ channel sequence (LilKT1) was identified in
lily pollen. To investigate the involvement of this K+
channel in generating the local K+ inward currents of the
electrical field, we expressed a codon usage-optimised
LilKT1 sequence in yeast cells to characterise the electrical
properties of this channel and its ability to complement a
K+ transporter-deficient yeast mutant. In addition, a
fluorescence-tagged LilKT1 was designed and is used to
monitor its localisation in the yeast expression system.
P13: 11
Heavy metals induce accumulation of starch in Lemna
minor (duckweed)
Brandt R., Franke S. and Appenroth K.
Universität Jena, Institut für Pflanzenphysiologie, Jena;
[email protected]
Application of arsenite, Co2+, Cu2+, Ni2+ and Zn2+ all
induced the accumulation of starch within the first 5 days in
continuous light. Thereafter, the starch content decreased.
Cd2+, Cr6+ and Hg2+ also induced accumulation of starch
but the starch levels remained approximately constant.
Other heavy metals like arsenate, Ag+ and Tl+ only
inhibited the accumulation of starch. The effective
concentrations for the induction of starch accumulation
were all in the µM-range. The dose-response curves were
bell-shaped. Application of DCMU following Cd2+-induced
accumulation of starch, decreased the starch content in the
next two days. In darkness, however, the decrease was
even faster and was not inhibited by Cd2+.
Our working hypothesis is as follows: Heavy metals block
the export of carbohydrates via the triose-phosphate
transporter out of chloroplasts resulting in accumulation of
starch in chloroplasts. More severe inhibition of
photosynthesis limits the supply of carbohydrates and less
starch is produced - as observed after longer time of heavy
metal application or at higher concentrations. DCMU also
blocks photosynthesis and the subsequent decrease of the
starch content shows that the starch degradation machinery
is intact in the presence of heavy metals. In darkness, the
faster decrease of the starch content might be caused by
operation of a maltose transporter (in contrast to the triosephosphate transporter in continuous light) that is perhaps
less inhibited by heavy metals.
P13: 12
HIGH MOLECULAR WEIGHT PROTEIN
COMPLEXES IN PLASMA MEMBRANES OF
HIGHER PLANTS
Schmitt A.1, Buck F.2 and Lüthje S.1
1
University of Hamburg, Germany; 2University of
Hamburg, University Hospital Hamburg-Eppendorf
(UKE),; [email protected]
The outer permeability barrier of a cell – the plasma
membrane (PM) – has to manage a couple of functions.
Different proteins are responsible for nutrient uptake, ion
transport, signalling, pathogen defence, and membrane
protection. Nowadays it is well known that most
physiological processes are not carried out by single
proteins, but rather by protein assemblies. The occurrence
of high molecular weight protein complexes has been
demonstrated in the PM of spinach (Spinacea oleracea L.)
leaves by blue-native PAGE, which is one of the state of
the art methods for the investigation of membrane proteins
POSTER ABSTRACTS
29
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and protein-protein interactions (Kjell et al (2004) Physiol
Plantarum 121: 546–555).
In the present work we investigated the occurrence of high
molecular weight protein complexes in PM isolated from
several plant materials and plant species. The general
existence of those complexes could be demonstrated for
cauliflower inflorescences, maize roots and Arabidopsis
leaves. Although several of these complexes appear
ubiquitous, some significant differences could be observed
in dependence on the material used. Protein spots of
Arabidopsis PM were cut out and analysed by mass
spectroscopy. Several proteins could be identified by
peptide analysis; among these were subunits of H+-ATPase,
aquaporins and other known proteins, but also hypothetical
proteins that were not described so far.
spanning regions and different subcellular targeting signals.
The localization of the proteins was investigated by GFP
fusion constructs. For two of them plastidic targeting was
confirmed experimentally. Furthermore, homozygous TDNA insertion mutants were isolated for each member of
the family. The knock-out mutants of the two plastidic
proteins exhibited severe phenotypes characterized by
dwarfish growth and yellowish leaf color. In addition, these
mutants showed significantly lowered photosynthetic
electron transport rates and starch levels. Therefore, these
mutants were named dwarf affected in photosynthetic
electron transport rate (DAP). We are now investigating
these mutants regarding the function of the affected
proteins.
P13: 15
P13: 13
How does a CNG channel work in vivo?
Dietrich P., Guinot D. and Dunkel E.
University of Erlangen, Germany; [email protected]
Following a long-lasting debate about the occurrence and
function of cyclic nucleotides in plants, these molecules
become more and more established as important second
messengers. Several stimuli have been identified that lead
to a rise in cAMP or cGMP and a role for these messengers
has been suggested in different processes, including
responses to salt stress, pathogen attack, and growth
regulation. Among the possible targets for cNMP action, a
family of ligand gated cation channels has been identified
in Arabidopsis thaliana. Unfortunately, due to major
difficulties to functionally express CNG channels, today’s
knowledge about the biophysical function and regulation of
these channels is still very limited. So far, no rapid, ligandbinding type of activation could be reported from
electrophysiological measurements in the plant plasma
membrane. Recently, our approach succeeded in
unravelling the biophysical nature of cyclic nucleotide
gated channels in vivo. We used Arabidopsis mesophyll
cells from wild type and cngc2 mutants to characterize the
CNGC2 gene product. Interestingly, our results do not
support the idea of a lag-phase before channel activation
but point to a rapid signaling cascade induced by cyclic
nucleotides. Combining this approach with the study of
cngc2 growth phenotypes and analysis of the cyclic
nucleotide-dependent Ca2+ homeostasis, a model on how a
plant cyclic nucleotide gated channel works in the plant
plasma membrane will be presented. We think that our
results shed some new light on the field of plant cyclic
nucleotide signaling.
P13: 14
Identification and characterization of Mep1, a novel
plastid envelope protein
Braeutigam A.1,2, Hoffmann-Benning S.2 and Weber
A.1,2
1
Heinrich-Heine-Universitaet Duesseldorf, Germany;
2
Michigan State University, USA; [email protected]
The plastid envelope membranes are the interface between
the metabolic networks of the cytosol and the plastid. Yet
todate only a few metabolite transport proteins have been
characterized at the molecular level. We hypothesized that
a comparative proteome analysis of Zea mays mesophyll
and Pisum sativum chloroplasts generates candidate
proteins that may catalyze the metabolite fluxes that are
enhanced in C4 plastids of Z. mays compared to C3
chloroplasts of P. sativum. A qualitative and semiquantitative proteome analysis of chloroplast envelopes of
Z. mays mesophyll and P. sativum will be presented.
We also present the analysis of Mep1 (Maize envelope
protein 1), one of the most abundant proteins in maize
mesophyll chloroplast envelopes. Arabidopsis thaliana
knock-out mutants deficient in the corresponding gene are
dwarfed and bleach upon exposure to high light intensity.
This phenotype is cured when the plants are grown in
elevated CO2 concentrations. We confirmed the plastid
localization and determined the expression pattern. A
metabolite analysis reveals a block of metabolism within
the plants and suggests a role for Mep1 as a
monocarboxylate transporter in A. thaliana. Currently we
are analyzing the transport capacities of Mep1 in whole
plastids. Isolated chloroplasts are fed with candidate
substrates and uptake is monitored with a clark-type
oxygen electrode. These results together with the
biochemical characterization of the heterologously
expressed proteins will ultimately reveal the transport
capacities of Mep1 in A. thaliana and Z. mays.
Identification and analysis of two plastidic membrane
proteins affecting growth and photosynthesis in
Arabidopsis thaliana
Marquardt D., Schneider A. and Flügge U.
Institute of Botany II, University of Cologne, Germany;
[email protected]
P13: 16
Membranes are the major barriers between the cytoplasm
and cell organelles. Therefore, a variety of transporters is
needed to mediate the exchange of metabolites, ions and
proteins between these compartments. We are analyzing a
family of five hydrophobic proteins in Arabidopsis thaliana
which are candidates for putative transporters. In silico
analysis with several prediction programs revealed that
these proteins contain more than five transmembrane
In plants, sucrose is the major transport form for
photoassimilated carbon and is both a source of carbon
skeletons and energy for plant organs unable to perform
photosynthesis (sink organs). Sucrose transporters are
responsible for sucrose transport over the cell membranes,
and they are potentially also involved in the phloem
unloading process in sink organs. All three known sucrose
transporters in potato plants follow a diurnal rhythm and
30
POSTER ABSTRACTS
Identification of SUT4-mRNA binding proteins
He H., Krügel U., Chincinska I., Grimm B. and Kühn
C.
Institute of Biology, Humboldt University of Berlin,
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we were able to show, that several sucrose transporter
mRNAs are phloem-mobile in grafted plants and between
host plants and the parasitic plant Cuscuta reflexa.
We focus on the physiological function of StSUT4 in
potato plants. StSUT4 is functional as sucrose transporter at
the plasma membrane if expressed in yeast. Western blot
analysis confirmed its plasma membrane localisation. Our
data show that StSUT4 is involved in regulated
developmental processes, such as flowering and
tuberization and that the half-life of StSUT4 mRNA is
regulated at the post-transcriptional level.
In order to identify proteins which are able to stabilize
sucrose transporter mRNAs during long distance transport
or which are involved in post-transcriptional regulation of
mRNA stability, we performed a yeast three hybrid screen
using StSUT4 mRNA as a bait. Up to now, we identified
several putative RNA-binding proteins, which potentially
play a role in stabilization of cell-to-cell movement of
StSUT4 mRNA.
P13: 17
Interaction between the plasma membrane H+ ATPase
and 14-3-3 proteins in lily pollen
Pöckl M., Pertl H. and Obermeyer G.
University of Salzburg, Dept. Molecular Biology,
Billrothstr. 11, Austria; [email protected]
The plasma membrane (PM) H+ ATPase plays an important
role in the germination of pollen grains and the subsequent
elongation of the pollen tubes by ‘energising’ the PM to
allow ion as well as nutrient uptake. It has been shown that
the activity of the PM H+ ATPase is regulated by binding of
14-3-3 proteins to its C-terminal autoinhibitory domain.
(CTAD). To further characterise the regulation of the PM
H+ ATPase by 14-3-3s in lily pollen, we investigated the
effects of components that enhance (FC, fusicoccin) or
decrease (AICAR (5-aminoimidazole-4-carboxamide-1-ßD-ribofuranoside), a membrane permeable 5’-AMP
analogue) the ATPase acitivity and the binding efficiency
of 14-3-3s. The effects on germination frequency, the
membrane potential, the external pH and on 14-3-3
interaction (overlay assays) were measured. After addition
of FC to pollen grains the germination frequency increased
and a fast acidification of the external medium was
observed whereas in the presence of AICAR no
acidification occurred and germination was inhibited. The
AICAR effect could be overruled by addition of FC.
Similar results were obtained by membrane potential
measurements: FC partially hyperpolarizes the PM and
AICAR showed no or depolarizing effects. To investigate
their direct effects on the interaction of 14-3-3s with the
PM H+ ATPase overlays assay with lily pollen 14-3-3s and
an isolation PM fraction were performed.
P13: 18
Internal and external Ca2+ ion availabilities differ in
controlling salt stress-induced chloride influx
Saleh L. and Plieth C.
[email protected]
Stress-induced anion transport into Arabidopsis root cells
can be monitored by fluorescence ratio imaging using
CLOMELEON, a FRET-based recombinant indicator. We
analysed the kinetics of chloride uptake into the cytoplasm
after onset of salt stress.
Chloride uptake is strongly dependent on the external free
Ca2+ ion concentration. It is typically inhibited by external
[Ca2+]ext > 1 mM and completely blocked, when [Ca2+]ext
exceeds 10 mM. These findings are in line with early
reports that Ca2+ meliorates salt stress in the field. In
contrast Cl--import into plants grown under low-[Ca2+]
conditions is slower and less pronounced. Thus, internal
and external Ca2+ ion availabilities have opposite effects.
Known are Cl--transporters in the tonoplast which are
activated by Ca2+. However, Cl--transporters which are
inhibited by Ca2+ have not yet been characterized on
molecular level. In order to get hold of the principal
transporters responsible for anion transport under salt stress
we started to perform chloride flux studies under influence
of different anion channel blockers and high-ceiling
diuretics. Blockers like NPPB and Niflumic acid do inhibit
salt stress-induced Cl- influx. Diuretics however seem to
have less influence.
These data and wash-out experiments suggest that
transporters of different characteristics in the plasmalemma
and in the tonoplast participate in salt stress-induced
chloride transport and storage, respectively.
P13: 19
Internal signals for different targeting of two viral
potassium channels
Balß J. and Thiel G.
TU Darmstadt, Germany; [email protected]
Until now only two viral channels with the hallmarks of K+
channels have been identified. Both are composed of only
about 100 aa and are the smallest proteins known to form a
functional potassium channel. One of these channels is Kcv
from the Paramecium bursaria chlorella virus (PBCV-1).
This virus infects certain isolates of unicellular eukaryotic
chlorella-like algae. The second channel, Kesv, was
detected in the genome of the Ectocarpus siliculosus virus
(EsV-1), his host is a marine brown algae. It is important to
mention that both channels have the same general
architecture of more complex K+ channels. Like the
prototype K+ channel KcsA they are composed of two
transmembrane domains connected by a pore loop
containing the typical selectivity filter motif.
A comparison of the two channels reveals that both
proteins have an overall similar structure. The only obvious
difference is in their very small cytoplasmic domains: Kcv
has a short N-terminus and lacks a C-terminus. Kesv on the
other hand has an appreciable cytoplasmic N- and Cterminus. In spite of the apparent structural similarity our
expressions studies in HEK293 cells revealed that one of
the channel (Kcv) is sorted into the secretory pathway
while the other channel (Kesv) ends up in the mitochondria.
Hence both cannels undergo different trafficking and
sorting in the cell. The main goal is to identify the
underlying signal sequence responsible for the different
sorting. My results suggest that the information for
membrane localisation is contained in the length and the
structure of the transmembrane domains.
P13: 20
Inverse regulation of TPC1 and TPK1 by 14-3-3
proteins
Beyhl D.1, Latz A.1, Marten I.1, Rienmüller F.1, Bertl
A.2, Eing C.3, Becker D.1 and Hedrich R.1
1
University of Würzburg, Institute of Plant Physiology and
Biophysics; 2Technical University of Darmstadt, Faculty of
Biology; 3Forschungszentrum Karlsruhe, IHM;
[email protected]
POSTER ABSTRACTS
31
P13
In the vacuolar membrane a considerable number of ion
channels, pumps and carriers are localized. They are
responsible for keeping ion homeostasis and transport of
metabolic solutes between the vacuolar and cytoplasmic
lumen, controlled by diverse cytosolic factors. While the
vacuolar proton pump and SV channels have been already
identified as targets for 14-3-3 proteins, here we studied the
interaction between TPK1 and TPC1 with specific 14-3-3
proteins in detail. The voltage-independent K+-selective
TPK1 channel was found to localize at the vacuolar
membrane of mesophyll cells from Arabidopsis thaliana
and specifically interacts with one 14-3-3 protein. In pull
down assays the high affinity of TPK1 to 14-3-3 was
proven. While 14-3-3 stimulated the activity of TPK1
channels, the voltage-dependent, cation non-selective TPC1
channels were affected in a reversed manner. The results
indicate that 14-3-3 proteins under certain conditions such
as prolonged salt stress are capable of shifting the
conductance of the vacuolar membrane from K+/Na+ to a
K+ dominated one.
P13: 21
Loss of the vacuolar cation channel, AtTPC1, does not
impair Ca2+ signals induced by abiotic and biotic
stresses
Wuennenberg P.1, Ranf S.2, Lee J.2, Becker D.3, Dunkel
M.3, Hedrich R.3, Scheel D.2 and Dietrich P.1
1
Institut of Biology, Molecular Plant Physiology, FAU
Erlangen-Nürnberg; 2Stress and Develop. Biol., Leibniz
Institut of Plant Biochemistry, Halle; 3Julius von Sachs
Institut, Mol. Plant Physiol. and Biophys., JMU Würzburg;
[email protected]
The putative two-pore Ca2+ channel TPC1 has been cloned
from several plant species and suggested to be involved in
responses to abiotic and biotic stresses. We show that TPC1
co-localizes with the K+-selective channel TPK1 in the
vacuolar membrane. Loss of TPC1 abolished Ca2+activated slow vacuolar (SV) currents, which were
increased in TPC1-overexpressing plants, compared to the
wild type. Fast vacuolar (FV) channels were not affected. A
third, Ca2+-insensitive cation channel could be resolved in
tpc1-2 knockout plants. Kinetics of ABA- and CO2-induced
stomatal closure were similar in wild-type and tpc1-2
plants, excluding a role of SV channels in guard cell
signalling in response to physiological stimuli. Likewise,
ABA-dependent reduction of root growth was not changed
in tpc1-2 compared to the wild type. Due to permeability of
SV channels to mono- and divalent cations, the question
arises whether AtTPC1 in vivo represents a source for Ca2+
entry into the cytosol. Ca2+ responses as measured in
aequorin-expressing wild-type, tpc1-2 as well as TPC1-ox
plants disprove a contribution of TPC1 to any of the
stimulus-induced Ca2+ signals tested, including abiotic and
biotic factors. In good agreement, stimulus- and Ca2+dependent gene activation was not affected by alterations in
TPC1 expression. Together with our finding that the loss of
TPC1 did not change the activity of hyperpol.-activated
Ca2+-permeable channels in the plasma membrane, we
conclude that TPC1, under physiological conditions,
functions as a vacuolar K+/Na+ channel without impact on
cytosolic Ca2+ homeostasis.
32
POSTER ABSTRACTS
P13: 22
MOLECULAR AND BIOCHEMICAL ANALYSIS OF
THE PLASTIDIC ADP-GLUCOSE TRANSPORTER
(ZMBT1) FROM ZEA MAYS
Kirchberger S.1, Leroch M.1, Huynen M.2, Wahl M.1,
Neuhaus H.1 and Tjaden J.1
1
Department of Biology, TU Kaiserslautern, Germany;
2
CMBI, University of Nijmegen, The Netherlands;
[email protected]
Physiological studies on the Brittle1 maize mutant have
provided circumstantial evidence that ZmBT1 is involved
in the ADP-Glc transport into maize endosperm plastids,
but up to now, no direct ADP-Glc transport mediated by
ZmBT1 has ever been shown. The heterologous synthesis
of ZmBT1 in E. coli cells leads to the functional integration
of ZmBT1 into the bacterial cytoplasmic membrane.
ZmBT1 transports ADP-Glc in counter exchange with ADP
with apparent affinities of about 850 µM and 465 µM,
respectively. Recently, a complete ferredoxin/thioredoxin
system has been identified in cereal amyloplasts and BT1
has been proposed as a potential Trx target protein.
Interestingly, we revealed that the transport activity of
ZmBT1 is reversibly regulated by redox reagents such as
diamide and dithiothreitol. The expression of ZmBT1 is
restricted to endosperm tissues during starch synthesis
whereas a recently identified BT1 maize homologue, the
ZmBT1-2, exhibits a ubiquitous expression pattern in
hetero- and autotrophic tissues indicating different
physiological roles for both maize BT1 isoforms. BT1
homologues are present in both mono- and dicotyledonous
plants. Phylogenetic analyses classify the BT1 family into
two phylogenetically and biochemically distinct groups:
The first group comprises BT1 orthologues restricted to
cereals where they mediate the ADP-Glc transport into
cereal endosperm storage plastids during starch synthesis.
The second group occurs in mono- and dicotyledonous
plants and is most probably involved in the export of
adenine nucleotides synthesized inside plastids.
P13: 23
Novel plant transporters for purines and cytokinins:
functional analysis of the AtAzg family
Maurino V.1, Grube E.1, Schumacher B.2, Flügge U.1
and Desimone M.2
1
Institute of Botany, University of Cologne; 2Zentrum für
Molekularbiologie der Pflanzen, University of Tübingen;
[email protected]
A high-affinity purine transporter of Aspergillus nidulans
(AnAzg, Aza-guanine resistant) has been recently
identified as a member of a novel protein family with
members in prokaryotes, fungi and plants. Two orthologous
proteins, AtAzg1 and AtAzg2, are encoded in the A.
thaliana genome. AtAzg1 was functionally expressed in a
yeast mutant deficient in adenine uptake and was shown to
mediate a H+-gradient-dependent high-affinity transport of
adenine with a broad substrate specificity including
adenine, hypoxathine, guanine, cytokinins and toxic purine
analogs. Transient expression of AtAzg1-GFP fusion
proteins in cultured A. thaliana cells and in onion epidermal
cells revealed that AtAzg1 is localized to the plasma
membrane indicating a function as cell importer. Azg1
knock-out mutants presented a conditional phenotype
resistant to purine analogs and toxic concentrations of
trans-zeatin (tZ) and, in contrast to the wild-type, azg1
knock-out seedlings did not accumulate cytokinin
conjugates after treatment with tZ. On the contrary, Azg1
P13
overexpressing lines showed hypersensitivity to purine
analogs and tZ. These lines also showed adenine and tZ
uptake rates several times higher than the wild-type. These
results indicate that AtAzg1 functions as a purine and
cytokinin importer in vivo. Promoter activity analysis
showed that AtAzg1 and Atzg2 gene expression is
modulated by cytokinins and auxins, respectively.
P13: 24
Peroxisomal ATP import is involved in fatty acid
oxidation
Linka N.1, Neuhaus E.2 and Weber A.1
1
Heinrich-Heine-Universität, Germany; 2Technische
Universität Kaiserslautern, Germany; [email protected]
Storage lipid mobilization is critical for seed germination.
Until the photosynthetic apparatus is established, the
seedling degrades fatty acids released from lipid to fulfil its
carbon and energy requirements. The subsequent break
down of fatty acids occurs in the peroxisome by the boxidation. To enter this pathway, the free fatty acids have
to be activated to their respective Coenzyme A derivatives
by ATP dependent Acyl-CoA sythethases. Fulda et al.
(2004) identified two peroxisomal enzymes which are
involved in the fatty acid activation. A loss-of-function led
to seedlings with an inhibition of the b-oxidation.
The inability to synthesize ATP necessitates ATP import
into peroxisomes. Therefore, a specific transport protein is
required to mediate the import of ATP. Here we present the
analysis of three candidates for peroxisomal ATP
transporters in Arabidopsis thaliana. We have
demonstrated that two of these proteins are located in the
peroxisomal membrane in yeast and in planta and that they
complement a yeast mutant impaired in peroxisomal ATP
import. In addition, we have studied the biochemical
properties of recombinant proteins using a proteoliposome
system which revealed that they catalyze an ATP/AMP
exchange.
Arabidopsis T-DNA insertion lines and RNAi plants were
generated to analyze the function of peroxisomal ATP
import for fatty acid oxidation. A detailed screen to test the
impact of impaired ATP uptake into peroxisomes will be
presented.
P13: 25
Phloem-localized Proton-coupled Sucrose Carrier
ZmSUT1 Mediates Sucrose Efflux under the Control of
the Sucrose Gradient and Proton Motive Force
Geiger D.1, Carpaneto A.2 and Hedrich R.1
1
Julius-von-Sachs-Institut für Biowissenschaften,
Universität Würzburg, Bot1; 2Istituto di Biofisica,
Consiglio Nazionale delle Ricerche, Genova, Italy;
[email protected]
The phloem network represents a long distance transport
pathway for nutrients and information. Although H+coupled sucrose carriers have been localized to the sieve
tube and the companion cell plasma membrane of both
source and sink tissues, knowledge of the molecular
representatives and the mechanism of the sucrose phloem
efflux is still scant. We expressed ZmSUT1, a maize
sucrose/H+ symporter, in Xenopus oocytes and studied its
transport characteristics. Using the giant-patch-clamp
technique we altered the electrochemical gradient across
the sucrose carrier and analyzed the currents generated by
the proton flux. Thereby we could show that ZmSUT1 is
capable of mediating both sucrose uptake into the phloem
(source) as well as desorption of sugar from the phloem
vessels into sink tissues. As predicted for a perfect
molecular machine the direction of the sucrose-coupled
proton current was reversible and depended on the sucrose
and pH gradient as well as the membrane potential across
the transporter (Carpaneto et al., 2005). To analyze single
steps in the transport mechanism of ZmSUT1 we
investigated the membrane capacitance (Cm) as well as
presteady-state currents in respect to their dependence on
sucrose, pH and membrane potential. Our results suggest
that sucrose-induced transport currents and charge
migration (presteady-state currents) upon voltage steps
arise from the same molecular mechanism in the ZmSUT1
protein. Therefore a simple kinetic model is sufficient to
predict the transport currents by the observed capacitive
presteady-state transients.
P13: 26
Physiological characterization and genetic analysis of
caesium and strontium accumulation in shoots of
Hauser A. and Schneider K.
GSF-National Research Center for Environment and
Health, Germany; [email protected]
In case of radioactive contamination with unstable isotopes
of caesium (137Cs, 134Cs) and strontium (90Sr, 85Sr) in our
environment, plants take them up and thus present a hazard
to the human food chain.Therefore, we are interested to
analyse the mechanism of their uptake at the physiological
and molecular level with the aim to reduce radionuclide
uptake by genetic modification of crops. Radiocaesium and
-strontium uptake assays for hydroponically grown
Arabidopsis thaliana were established and used for
analysing a set of 86 Arabidopsis ecotypes. The
incorporated radioactivity was measured in 20-day-old
rosette leaves by gammaspectrometry. The variation
between high- and low-uptake ecotypes was about twofold
for both caesium and strontium, but either element did not
influence the accumulation of the other allowing a
combined screen.Caesium and strontium are non-essential
ions, but share similar chemical and physical properties
with essential minerals like potassium and calcium. For a
genetic analysis, a segregating F2 population was
constructed. Currently, F3 families are being phenotyped
for their contents of caesium, strontium, potassium and
calcium, and a genetic map is under development. So far,
no correlation was observed between caesium and
potassium in the shoots whereas a tight correlation between
strontium and calcium was found.A QTL analysis will
enable the identification of genomic regions with an impact
on the accumulation of the ions.
P13: 27
Protein targeting across and into multiple membranes
of diatom plastids
Gruber A., Vugrinec S. and Kroth P.
[email protected]
Plastids of diatoms and related algae evolved by secondary
endocytobiosis, which is the uptake of a eukaryotic alga
into a eukaryotic host cell and its subsequent reduction into
an organelle. As a result diatom plastids are surrounded by
four membranes. Protein targeting of nucleus encoded
plastid proteins across these membranes depends on Nterminal bipartite presequences consisting of a signal and a
transit peptide-like domain. A conserved amino acid motif
of unknown function at the cleavage site of the signal
POSTER ABSTRACTS
33
P13
peptides (ASAFAP) is particularly important for plastid
targeting. We characterised the requirements for stromal
presequences by screening of genomic databases and by
fusion of different presequence domains to Green
Fluorescent Protein. Only the aromatic amino acids
phenylalanine, tryptophan, tyrosine and the bulky amino
acid leucine at the +1 position of the predicted signal
peptidase cleavage site allowed plastid import in vivo. This
corresponds to the occurrence of amino acids in native
plastid
targeting
presequences
of
the
diatom
Phaeodactylum tricornutum.
Metabolites also have to cross the four plastid membranes.
Membrane transporters for nucleotides and triose
phosphates identified in diatom genomes differ in their
presequence structure possessing either a full bipartite
presequence including an “ASAFAP”-motif or a bipartite
presequence lacking the conserved motif, or no
recognizable presequence at all. Multiple copies of
metabolite transporter genes might thus explain the
multiple membrane transport of metabolites
P13: 28
Regulatory aspects of V-ATPase structure as revealed
by in vivo FRET-analysis
Seidel T., Schnitzer D., Golldack D. and Dietz K.
University of Bielefeld, Germany; [email protected]
The V-ATPase is an essential protein complex present in
all eukaryotes. V-ATPases are essential for the cytosolic
pH homeostasis, the generation of a proton motive force
and involved in developmental events like cell expansion
and stress defense like vacuolar sequestration of toxic
solutes. Structural as well as regulatory aspects of VATPase function were addressed by fluorescence resonance
energy transfer (FRET). This in vivo technique enables
measurements of e.g. labile complexes such as the VATPase and allows to investigate the structural impact of
inhibitors and effectors in the cellular context. The work
focused on the reversible dissociation, a regulatory
mechanism which was postulated to silence V-ATPase
activity in yeast under conditions of glucose deprivation.
Within minutes after glucose withdrawal the cytosolic V1
subsector dissociates from the membrane integral sector V0.
Interaction between glycolytic aldolase and V-ATPase
subunit E triggers the dissociation in yeast and was
identified in A. thaliana as well. The interaction was
mapped to the N-terminal domain of VHA-E. However, VATPase activity was only slightly affected by
desoxyglucose, an inhibitor of glycolysis, although
interaction of glycolytic aldolase and subunit E might link
V-ATPase activity directly to glycolysis. The data suggest,
that photoautotrophic organisms like plants prefer a
regulation via biochemical modulation depending on e.g.
redox-conditions rather than dissociation in dependence on
glucose-availability.
P13: 29
Shuttle transport of potassium ions between subsidiary
cells and guard cells in the maize stomatal complex
Mumm P.1, Hilgarth E.1, Fromm J.2, Hedrich R.1,
Roelfsema M.1 and Marten I.1
1
Universität Würzburg LS Botanik I, Germany; 2FG
Holzbiologie der TU Muenchen, Germany;
[email protected]
34
POSTER ABSTRACTS
The stomatal complex of Zea mays consists of two guard
cells and two flanking subsidiary cells. According to the
shuttle transport hypothesis, during stomatal closure K+
ions are released from guard cells into the apoplast and
taken up by subsidiary cells. During stomatal opening the
direction of K+ flux is reversed. Although studies of the
maize stomatal complex revealed differential expression of
certain cloned K+ channels in subsidiary and guard cells
[Büchsenschütz et al. (2005) Planta 222: 968], regulation of
the antiparallel-directed K+ transport still remains unclear.
Applying the microelectrode-impalement technique on
intact plants, here we observed a reversed membrane
polarization in guard cells and subsidiary cells during lightinduced stomatal opening. In addition the cytosolic K+
activity of subsidiary cells increased or decreased by about
10 mM during stomatal movement. Estimated volumes of
guard cells and subsidiary cells, however, implicate that the
10-mM-K+-activity change might not be sufficient to drive
stomatal movement. Since we identified plasmodesmata
between subsidiary and epidermal cells, it is not clear
whether the observed K+ activity changes of subsidiary
cells are exclusively related to K+ transport across the
plasma membrane of subsidiary cells. The presented results
will be discussed in the light of the shuttle transport
hypothesis.
P13: 30
Structural analysis of the peripheral stalk of
Arabidopsis thaliana V-ATPase
Schnitzer D., Seidel T., Hanitzsch M., Sander T.,
Golldack D. and Dietz K.
Bielefeld University, Germany; [email protected]
The H+-V-ATPase of A. thaliana consists of a membraneembedded V0 and a cytosol-oriented V1-domain, and
functions as a H+-translocating electrogenic pump in the
endomembrane system including the tonoplast. V1 is built
from a hexameric catalytic head, a central stalk and an
additional peripheral stalk, the latter with the VHAsubunits H, C, E and G. VHA-E and -G are encoded by
three isogenes each. To study the subunit assembly and
stochiometry, mesophyll protoplasts were transfected with
chimeric constructs of VHA subunits and fluorescent
proteins. In vivo FRET- (Förster resonance energy transfer)
efficiency analysis indicated that the peripheral stalk
contains at least two copies of VHA-E with a preference of
forming homodimers, such as VHA-E3/E3, instead of
heterodimers, e.g. VHA-E1/E3. Furthermore the FRETresults show a tight interaction between the subunits E and
G with only a low preference of interaction between
different isoforms, although G3 and E2 are both pollenspecifically expressed proteins. Results from co-expression
experiments in E. coli support the proposed subunit
interactions. Purification of 6xhis-tagged VHA-G from E.
coli expressing both tagged VHA-G and untagged VHA-E
resulted in enrichment of VHA-E. It is concluded that the
peripheral stalk of A. thaliana V-ATPase involves a tight
interaction between subunits VHA-G and -E.
P13/P14
P13: 31
The amino acid Lys can be in a deprotonated state
within the protein/lipid context of a K+ channel.
Gebhardt M.1, Tayefeh S.1, Baumeister D.1, Hertel B.1,
Moroni A.2, Kast S.1 and Thiel G.1
1
TU Darmstadt, Germany; 2Università degli Studi di
Milano, Italy; [email protected] K+
channel Kcv from the chlorella virus PBCV-1 is with only
94 amino acids truly minimal. But in spite of this small size
the channel protein still has the essential structural and
functional hallmarks of more complex K+ channels.
Because of this structural simplicity of a functional channel
this protein offers a good model system for analysing basic
structure function correlates in K+ channel proteins.
One interesting amino acid in the protein structure is a
lysine at position 29. This amino acid is conserved within
the family of other K+ channels isolated from viral origin.
Structural predictions suggest that this amino acid is
located at the downstream end of the first transmembrane
domain close to the lipid/fluid interface. Computational
studies of the Kcv protein structure by molecular modelling
and molecular dynamics simulations revealed that such a
structure with membrane-exposed lysine is stable and able
Uptake of potassium from poor soils can also be facilitated
by improved root architecture and, particularly, root hairs
are known to be of importance for the mineral acquisition.
They enable plants to exploit new undepleted soil layers
with a net result similar to activation of a high affinity
uptake system.
We found that tiny root hair 1 mutation blocks transition
between initiation and elongation of root hairs in
Arabidopsis indicating that the TRH1 gene product is a key
regulator of root hair development. Interestingly, the TRH1
gene encodes a potassium transporter belonging to
KT/KUP/HAK gene family. Analyzing 86Rb+ fluxes in
Arabidopsis root we found that the transporter functions in
wide range of K+ concentrations and is accountable for
approx. 40% of total potassium accumulation in low
micromolar range of concentrations. Using pTRH1-GUS
construct expression and qRT-PCR we demonstrated that
transcription of the TRH1 gene is controlled by sucrose.
Such control has dramatic implications for root
development and potassium nutrition. The importance of
sugar-dependent regulation for balanced nutrient uptake in
roots will be discussed.
P14: MOLECULAR
PHYSIOLOGY OF ALGAE
P14: 1
Grazing on phytoplankton: the contribution of microand mesozooplankton and in controlling phytoplankton
biomass
Löder M.1, Kraberg A.1, Aberle-Malzahn N.1, Klaas C.2
and Wiltshire K.1
1
Alfred-Wegener-Institut, Biologische Anstalt Helgoland,
Germany; 2Alfred-Wegener-Institut, Bremerhaven,
The original idea of the pelagic trophic structure was a
linear chain from autotrophic phytoplankton as primary
producers
via
microzooplankton
through
to
mesozooplankton as “top” predators. We now know that
to conduct K+ ions only if Lys29 is deprotonated i.e. not
charged. This may hint at a Lys pKa that is strongly shifted
in the protein/lipid context compared to its pKa in water.
To examine the possibility that Lys29 can be deporotonated
we mutated Lys29 into amino acids with other properties.
The functional analysis of these mutants supports the view
that position 29 in Kcv can be occupied by a non-charged
amino acid without consequence for function.
P13: 32
The role of the TRH1 transporter in K+ uptake and
root development.
Grabov A.1, Rigas S.2, Hatzopoulos P.2, Dolan L.3 and
Vicente-Agullo F.1
1
Imperial College London, United Kingdom; 2Agricultural
University of Athens, Greece; 3John Innes Centre, United
Kingdom; [email protected]
Potassium uptake is facilitated by at least two transport
systems characterized by different affinity to the substrate.
While a low affinity system enables high rate of potassium
uptake when the nutrient is abundant, high affinity
transporters are crucial for the plant survival at nutrient
deficiency.
this is not a linear interaction but rather constitutes a
complex
food
web.
In-situ
measurements
of
microzooplankton and mesozooplankton grazing have
demonstrated the importance of these groups as
phytoplankton grazers in coastal and pelagic systems. In
addition, a trophic overlap between micro- and
mesozooplankton can also be expected. Still, not much is
known about the species-specific feeding preferences and
the dietary competition of dominant ciliates, dinoflagellate
and copepod species on the phytoplankton species that
dominate natural assemblages.As a starting point,
investigations on micro- and mesozooplankton grazing
were conducted using key species of phytoplankton,
ciliates, dinoflagellates and copepods occurring in the
North Sea at different times throughout the year.For the
selection of key species the Helgoland long-term data
series, one of the world’s longest running and detailed
plankton data series, was used. The aim of these grazing
experiments was to clarify which algae are preyed upon by
both micro- and mesozooplankton, to estimate their relative
contribution to phytoplankton grazing and to show
selectivity patterns. First results of the microzooplankton
and mesozooplankton grazing experiments will be
presented. The question whether microzooplankton can
regulate phytoplankton blooms will be analysed and
addressed.
P14: 2
Attachment of a histidine tag to the stromal loop of the
D1 subunit of photosystem II
Hänßgen I. and Johanningmeier U.
Martin-Luther-Universität Halle-Wittenberg, Germany;
[email protected]
Histidine (His) tags are widely used as fusion tags for the
isolation of proteins using metal affinity chromatography
methods. In most cases the His-tag is attached to the N- or
C-terminal end of the protein, assuming that these are the
most tolerant regions with respect to protein structure and
function. For the highly conserved D1 subunit of
photosystem II, both termini are supposed to play important
roles for its function, thus prohibiting tag fusions at these
sites. We have identified a rather flexible region within the
POSTER ABSTRACTS
35
P14
stromal loop of the D1 protein from the unicellular green
algae Chlamydomonas reinhardtii, which allows the in vivo
insertion of various peptides, among them a tag consisting
of 10 His residues. Although photosynthetic electron
transport rates in His-tagged D1 mutants are reduced, the
D1 protein can be easily isolated from thylakoid membrane
preparations, allowing further analyses of this highly
hydrophobic protein.
P14: 5
P14: 3
Glucose-6-phosphate isomerase (GPI) has an essential
function in both catabolic glycolysis and anabolic
gluconeogenesis and is universally distributed among
eukaryotes, Bacteria and some Archaea. In addition to the
cytosolic GPI, land plant chloroplasts harbor a nuclear
encoded isoenzyme of cyanobacterial origin that is
indispensable for the oxidative pentose phosphate pathway
(OPPP) and plastid starch accumulation. We established
twelve new GPI sequences from rhodophytes, the
glaucophyte Cyanophora paradoxa, a ciliate and all orders
of complex algae with red plastids (haptophytes, diatoms,
cryptophytes, dinoflagellates). The evolution of cytosolic
GPI is largely in agreement with SSU analyses, which
indicates that it is a specific marker of the host cell. A
distinct
subtree
comprising
alveolates
(ciliates,
apicomplexa, Perkinsus, dinoflagellates), stramenopiles
(diatoms, Phytophthora [oomycete]) and Plantae (green
plants, rhodophytes, Cyanophora) might suggest a common
origin of these superensembles. Finally, in contrast to land
plants where the plastid GPI is of cyanobacterial origin,
chlorophytes and rhodophytes independently recruited a
duplicate of the cytosolic GPI that subsequently acquired a
transit peptide for plastid import. A secondary loss of the
cytosolic isoenzyme and the plastid localization of the
single GPI in chlorophycean green algae is compatible with
physiological studies. Our findings reveal the fundamental
importance of the plastid OPPP for Plantae and document
the plasticity of primary metabolism.
Characterization of a transgenic diatom that
accumulates chlorophyll b
Werner S.1, Veith T.2, Gruber A.3, Kroth P.3, Büchel
C.2, Paulsen H.1 and Lohr M.1
1
Johannes Gutenberg-University Mainz, Germany; 2Johann
Wolfgang Goethe-University, Frankfurt, Germany;
3
University Konstanz, Germany; [email protected]
Diatoms belong to the chromophytic algae which are
characterized by the lack of chlorophyll b and instead
contain chlorophyll c. We have genetically engineered the
diatom Phaeodactylum tricornutum by introducing a gene
encoding chlorophyllide a oxygenase (CAO) which in
vascular plants is responsible for the formation of
chlorophyll(ide) b from chlorophyll(ide) a. By screening of
pigment extracts of the transformants with high
performance liquid chromatography we identified a clone
that accumulated up to 20 % of the total chlorophyll as
chlorophyll b and its precursor 7-hydroxy-chlorophyll a.
Growth experiments showed that the concentration of the
new pigments decreased to almost zero when the cells
entered the stationary phase and that the transformants
grew more slowly than wild-type cells, suggesting that the
presence of chlorophyll b has a negative effect on
photosynthetic efficiency. Fluorescence excitation and
emission spectra of whole cells, however, indicated that at
least part of the chlorophyll b participates in energy transfer
to chlorophyll a. This was further corroborated by
spectroscopic analyses of samples containing either the
fucoxanthin-chlorophyll-proteins of the light-harvesting
antennae or the core complexes of both photosystems.
Pigment analyses of the samples indicated that
chlorophyll b preferentially accumulates in the core
complexes. The potential significance of the results for
understanding the differential evolution of photosynthetic
pigment-protein complexes in chlorophyll a/b- and
chlorophyll a/c-containing organisms will be discussed.
P14: 4
Effects of nitrite on the rate of growth and pigmentation
in Dunaliella tertiolecta from Iran
Saadatmand S. and Soltany S.
Islamic Azad University,science and research branch,
Teheran, Iran; [email protected]
Dunaliella tertiolecta is an unicellular and green algae
(chlorophyceae). This algae produces glycerol, vitamin E
and β_carotene under stress conditions. In this study, D.
tertiolecta was isolated from Urmia Lake in Iran, then
cultivated in Johnson,s medium with different nitrite
concentrations(0 (control),3,6,9 and 12 mM).The effects of
nitrite treatments studied on the rate of growth and pigment
content (chlorophyll and β_corotone). The results showed
that in D. tertiolecta, in the high(12 mM) and low (3 mM)
nitrite concentrations, pigment content decreased and in 9
mM nitrite treatment, pigment content increased. As well
as in 9mM nitrite treatment, the rate of growth was the
higer than the other treatments.
36
POSTER ABSTRACTS
Evolution of the Glucose-6-phosphate Isomerase: The
Plasticity of Primary Metabolism in Photosynthetic
Eukaryotes
Grauvogel C.1, Brinkmann H.2 and Petersen J.1
1
TU Braunschweig, Institut fuer Genetik, Germany;
2
Université de Montréal, Département de Biochimie,
P14: 6
Expression pattern of msrA genes under various stress
conditions in the green alga Chlamydomonas
reinhardtii
Schulze J. and Johanningmeier U.
Martin-Luther-Universität Halle-Wittenberg, Germany;
[email protected]
Reactive oxygen species (ROS) are continuously produced
as an unwanted by-product of cellular metabolism.
Organisms have developed a set of enzymatic and nonenzymatic detoxification processes to fight these toxic
forms of oxygen. Under stress conditions like high light,
cold, heat or drought, ROS levels can increase to an extent
which overwhelms the detoxification system and severely
damages DNA, lipids and proteins. In some proteins certain
Met-residues appear to be especially susceptible to
oxidation resulting in reduced enzyme activity or even loss
of function. Interestingly, oxidation of Met to Metsulfoxide is reversible through the action of methionine
sulfoxide reductases (MSRs) which in this way repair
oxidized Met-residues in proteins. The green alga
Chlamydomonas reinhardtii contains four genes encoding
MSRAs which exhibit a different expression pattern under
stress conditions like high light, UV radiation, cold, heat
and darkness. According to a TargetP analysis, MSRA1
and MSRA4 are presumably located in the cytosol,
MSRA2 and MSRA3 in the chloroplast and mitochondria,
respectively. We show here that in Chlamydomonas msrA4
is constitutively expressed and represents a highly abundant
P14
transcript. MsrA2 is highly expressed under high light, UV
radiation and heat but only weakly under control
conditions, cold stress and darkness. MsrA1 is continously
present but slightly up-regulated in high light. MsrA3
shows overall weak signals under the chosen experimental
conditions.
P14: 7
Freshwater diatoms in stromatolite forming processes:
a polyphasic approach to assess their biodiversity in two
hardwater creeks
Brinkmann N.1, Behnke A.2, Jahn R.3 and Friedl T.1
1
Universität Göttingen, Experimentelle Phykologie und
SAG; 2TU Kaiserslautern, Fachbereich Biologie, Abteilung
Ökologie; 3Botanischer Garten und Botanisches Museum,
Berlin-Dahlem, FU-Berlin; [email protected]
Biofilms on calcareous tufa are widespread in hardwater
creeks and are dominated by diatoms and cyanobacteria
producing high amounts of exopolymers that possibly play
a key role in CaCO3 nucleation and calcification processes.
In addition, photosynthesis seems to have a significant
impact on the carbonate equilibrium within the
algal communities occur there in high abundances on
moist walls in close vicinity to white fluorescence bulbs
where they receive relatively high light intensities (up to 19
µmol m-2 s-1), but only for very short periods, i.e. a monthly
average of 5 hrs (winter) to 100 hrs (summer) depending on
the number of visits by tourists. In an ongoing study using a
polyphasic approach including SSU rRNA gene sequence
analyses and culture experiments, the diversity of the algal
community and their adaptation strategy towards low light
will be studied. The localities varied whether a still
unidentified diatom (colony-forming pennales) or a coccoid
green alga was dominant; both were intermixed with
filamentous or unicellular cyanobacteria which were never
dominant. Cloning/sequencing revealed a slightly higher
number of phylotypes than morphotypes. There were two
non-related phylotypes of Leptolyngbya and two
phylotypes of Nostoc. The unicellular cyanobacteria were
distributed on three independent lineages; for each of them
there were no close relatives available. Phylogenetic
analyses showed the dominant coccoid green alga being
most closely related to a still undescribed member of
Sphaeropleales (Chlorophyceae) from tropical soils.
Comparative culture experiments will show whether the
algal community of the shelter is adapted to extended
periods without light compared to their phylogenetically
closest relatives.
P14: 9
Photosynthesis in space: new strategies to generate
space-adapted algae strains
Bertalan I., Krebs M. and Johanningmeier U.
MLU Halle-Wittenberg, Germany; [email protected]
Plants are able to store solar energy in chemical bonds by a
process called photosynthesis. They extract CO2 from the
atmosphere, fix it as carbohydrates and at the same time
emit oxygen into the atmosphere. Continous oxygen
evolution is vital for all higher life forms on earth and
results from the splitting of water molecules - a process
which is catalyzed by the photosystem II (PSII) complex.
PSII is also a central point of regulation, being responsive
to various physical and physiological parameters. In space
exploration, it is of special importance to consider that
complex space radiation is specifically damaging the PS II
microenvironment of such biofilms. In this ongoing project
the key player diatoms involved in stromatolite forming
processes of two exemplar creeks, the Deinschwanger Bach
(Franconian Alb) and the Westerhöfer Bach (Harz
Mountains), were analysed. The main focus of this study is
to generate molecular signatures of diatoms from the
calcareous
biofilms
using
culture-independent
cloning/sequencing as well as cultured material in order to
establish a reference sequence database for rapid and
unequivocal identification. DGGE community profiling
will enable a rapid and finer-scale resolution of spatial
variations along the creek as well as seasonal variations.
P14: 8
Freshwater microalgal communities at an unusual low
light habitat on Helgoland island
Rosenkranz H., Mohr K. and Friedl T.
University of Goettingen EPSAG, Germany; [email protected]
A shelter on Helgoland island, used during World War II
and situated below a 20 meters thick sandstone cover,
provides an habitat for algae unusual with regard to light:
reaction centre, thus reducing photosynthetic efficiency and
oxygen evolution capacity. Bioregenerative life-support
systems might be severely perturbed at this point.
As the photosynthetic apparatus has adapted to terrestrial
conditions only, we are trying to adapt a particularly stresssusceptible element of the photosynthesis apparatus - the
D1 subunit of PS II - to space conditions by a strategy of
directed evolution. We are using the model organism
Chlamydomonas reinhardtii because this unicellular green
alga is easily amenable to genetic modification. The alga
was already tested in space under shielded conditions in the
past, but it was never exposed to direct radiation as they
prevail in the experimental platform Biopan. In the Photo I
experiment the alga was - only protected by glass or quartz
filters - exposed to space radiation for the first time.
P14: 10
Pigment Analysis of the Eyespot Apparatus from
Chlamydomonas reinhardtii
Mollwo A.2, Bauch M.1, Kreimer G.2 and Lohr M.1
1
Johannes Gutenberg-University Mainz, Institute of
General Botany, Germany; 2Friedrich-Alexander
University Erlangen, Institute of Biology, Germany;
[email protected]
Phototaxis is a ubiquitous phenomenon among motile
algae, and in many cases these algae possess a specialized
organelle for light perception, the so called eyespot
apparatus. In green algae, part of the eyespot apparatus
consists of lipid globules that are heavily enriched in
carotenoids. So far, the pigment composition of the eyespot
has been determined only for a few algae. Among them is
the eyespot apparatus of the chlorophyte Spermatozopsis
similis, that was shown to be massively enriched in the
acyclic carotenoid lycopene (y,y-carotene) and the
monocyclic g-carotene (b,y-carotene) [1]. For C.
reinhardtii, only a thin-layer chromatographic analysis of
the eyespot had been performed, indicating that the bicyclic
b-carotene (b,b-carotene) is the major pigment [2]. Recent
improvements in the isolation of eyespot apparatuses from
C. reinhardtii resulting in highly enriched eyespot samples
[3] led us to reexamine their pigment content by high
performance liquid chromatography using a photodiodearray detector. Our results confirm the prominent role of b-
POSTER ABSTRACTS
37
P14/P15
carotene in the eyespot apparatus of C. reinhardtii, but
several other carotenes were tentatively identified, among
them a-carotene (b,e-carotene) and g-carotene, while only
trace amounts of xanthophylls and chlorophylls were
present.
References:
[1] Grung, M. et al. (1994), Planta 193, 38-43
[2] Ohad, I. et al. (1969) In: Progress in Photosynthesis
Research, vol. I, pp. 284-295; H. Metzner, ed.; IUBS,
Tübingen
[3] Schmidt, M. et al. (2006), Plant Cell 18, 1908-1930
P14: 11
Substrate Specificity of native and recombinant
xanthophyll de-epoxidases from three vascular plants
and a diatom
Knüfer J., Herwig S., Novoisky J., Volz B. and Lohr M.
Johannes Gutenberg-University, Germany;
[email protected]
Vascular plants and green algae employ the so called
violaxanthin (Vx) cycle for photoprotection, while many
chromalveolate algae like, e.g., diatoms, haptophytes and
dinoflagellates utilize the diadinoxanthin (Ddx) cycle,
instead. Metagenomic studies indicate that the deepoxidation of Vx in vascular plants and green algae and of
Ddx in diatoms and haptophytes is catalyzed by
homologous enzymes. We have cloned the respective genes
from the vascular plants Arabidopsis, tobacco and wheat
and from the diatom Phaeodactylum tricornutum. After
heterologous expression in Escherichia coli we
characterized the de-epoxidation kinetics of the
recombinant proteins with respect to the two substrates Vx
and Ddx. While the enzymes from the three vascular plants
converted Vx between 1.5 and 2 times faster than Ddx the
de-epoxidase from the diatom clearly preferred Ddx over
Vx. This suggests an adaptive change in the substrate
specificity of the diatom enzyme. Further experiments
proved that the substrate preferences of the recombinant
proteins do not differ significantly from those of the native
enzymes. Thus, we have established a platform for
identification by site-directed mutagenesis of the domains
that define the differential substrate specificities of the
proteins from vascular plants and diatoms
P14: 12
Tetratricopeptide-proteins in the cyanobacterium
Synechocystis PCC 6803
Stelljes C., Klinkert B., Ratke J. and Nickelsen J.
Ludwig-Maximilians-Universität München, Germany;
[email protected]
Recently, the ubiquitous tetratricopeptide repeat (TPR)
motif, which mediates protein-protein interactions has been
found in several nucleus-encoded factors which control
chloroplast biogenesis in both green algae and vascular
plants. Computer-assisted homology searches now revealed
a total number of 23 putative TPR-ORFs whithin the entire
genome of the cyanobacterium Synechocystis sp. PCC
6803, the function of which are mainly unknown. The
insertional inactivation of four of these ORFs, slr2048,
slr0151, slr1644 and slr1956 led to reduced growth
compared to the wildtype and a significant reduction of
photosynthetic
oxygen
production.
Fluorescence
spectroscopy and molecular analysis of the mutant showed
a significant reduction in photosystem II (PSII) content.
Interactions between the TPR protein encoded by the
38
POSTER ABSTRACTS
slr2048 gene and the precursor form of D1 are shown. The
data are discussed in context with recent models for the
subcellular localization of initial steps of biogenesis of
cyanobacterial photosystems.
P15: N/S METABOLISM
P15: 1
A Branched-Chain Aminotransferase involved in
primary amino acid and secondary glucosinolate
metabolism
Knill T.1, Schuster J.1, Reichelt M.2, Gershenzon J.2 and
Binder S.1
1
Universität Ulm, Germany; 2Max-Planck-Institut für
Chemische Ökologie Jena, Germany; [email protected]
Glucosinolates (mustard oil glucosides) are sulfur- and
nitrogen-containing secondary plant products mainly found
in the order of the Capparales. The biosynthesis of aliphatic
glucosinolates comprises three major phases starting with
methionine chain elongation. In this cycle methionine is
elongated by one or several methylene groups. While
several enzymes acting in later phases of glucosinolate
biosynthesis
have
been
characterized
the
methylthioalkylmalate synthases (MAM) and the branchedchain aminotransferase (BCAT4) are so far the only
proteins unambigously assigned to this pathway. In
previous studies we found that BCAT4 catalyzes the initial
deamination of methionine to 4-methylthio-2-oxobutyrate.
Here we present the in vitro and in vivo characterization of
another branched-chain aminotransferase. Substrate
specificity assays with the recombinant protein reveal
substantial conversion with the intermediates of the
methionine chain elongation pathway as well as with the
standard substrates, the 2-oxo acids of Val, Leu and Ile.
This is confirmed by the in vivo analysis of the
corresponding knock-out mutant. The metabolite profile of
the mutant corroborates that this branched-chain
aminotransferase most likely catalyzes the conversion of
medium chain 2-oxo acids to the respective Met derivatives
and at the same time is involved in branched-chain amino
acid biosynthesis. Thus the further examined
aminotransferase seems to be active in primary and
secondary metabolism.
P15: 2
Comparative investigation of Synechocystis sp. PCC
6803 wild type, a PsbO-free mutant, a PsbY-free
mutant, and a PsbO-free/PsbY-free double mutant
Schlebusch M.1, Zinchenko V.2 and Michel K.1
1
Universität Bielefeld, Germany; 2Moscow State
Previously we have shown that a complex interrelationship
between photosynthesis/ respiration and L-arginine
catabolism exists in the cyanobacterium Synechocystis sp.
PCC 6803. A comparative analysis of Synechocystis sp.
PCC 6803 wild type (WT) and a PsbO-free mutant
provided evidence that the PsbO-free mutant could grow
well, while in WT substantial amounts of cyanophycin
accumulated and a severe reduction of the thylakoid
membranes with a simultaneous partial loss of its
photosynthetic activity was observed, when cells were
cultivated on L-arginine as sole N-source and when
illuminated with a light intensity of 200 µmol photon m-2 s1
(relatively high light intensity). This suggests that a small
P15
change in photosystem II has a drastic effect on L-arginine
metabolism. To obtain more information on this complex
interrelationship, a PsbY-free mutant and a PsbOfree/PsbY-free double mutant were included in these
investigations. Both these mutants have problems to grow
on L-arginine as sole N-source when the light intensity is
high. We will present an extensive comparative
investigation of these four Synechocystis sp. PCC 6803
strains with respect to photosynthetic and respiratory
activities, 77 K pigment fluorescence, as well as with
respect to the expression of relevant mRNA’s and proteins.
P15: 3
Different mechanisms of ammonium-induced growth
retardation in fully developed Phaseolus vulgaris leaves
and in Arabidopsis seedlings
Hansen U.1, Hoffmann A.1, Guo S.2, Zhu Z.3, Gerendas
J.4, Schinner K.1, Milde S.5, Desel C.6, Kaiser H.6 and
Sattelmacher B.4
1
Zentrum für Biochemie und Molekularbiologie, Germany;
2
Resource and Environmental Science, Agricultural
Uni.Nanjing, China; 3Horticultural Plant Growth Develop
& Biotech., Hangzhou, China; 4Institute of plant nutrition
and soil science, University of Kiel, Germany; 5Institute of
Zoology, University of Kiel, Germany; 6Institute of Botany,
University of Kiel, Germany; [email protected]
NH4+-grown leaves of Phaseolus vulgaris suffer from a
deficiency of electron acceptors in the chloroplasts leading
to poor growth under high-light conditions. A lower CO2
compensation point in NH4+-grown plants indicates the use
redox export to the mitochondria to replace the GOGAT
electron sink. This leads to enhanced generation of toxic
radicals and causes damage to the plant. This hypothesis is
supported by differences in lipid peroxidation, by N-formdependent activation of detoxification enzymes, and by the
sensitivity of electron flux and O2 evolution to oligomycin,
antimycin and SHAM. At 14 days, primary leaves of A.
thaliana were well developed in NO3--grown seedlings, but
missing in NH4+-grown seedlings. Photosynthetic activity
as measured by CO2 uptake was half as much in NH4+grown seedlings as compared to NO3--grown seedlings
whereas chlorophyll fluorescence revealed much
smallerdifference in photosynthetic activity. Transmissionelectron micrographs showed no starch deposits in NH4+grown chloroplasts. Organic acids were totally absent in
NH4+-grown seedlings and free amino acids showed
different patterns, especially large amounts of Arg and Gln
in NH4+-grown seedlings. These findings together with
differences in gene expression led to the hypothesis, that
NH4+-grown plants still live from storage lipids whereas
NO3--grown plants have already employed photosynthesis
as the main energy source. This implies that the N form
exerts an influence on metabolism already before
photosynthesis starts, in contrast to the mechanism
suggested for fully grown leaves of P. vulgaris.
P15: 4
Expression and characterization of a cystine lyase and
tyrosine aminotransferase from Arabidopsis thaliana
Holländer-Czytko H., Muthreich M., Pollmann S. and
Sandorf I.
Ruhr-Universität Bochum, Lehrstuhl Pflanzenphysiologie,
Bochum, Germany; [email protected]
Looking for octadecanoid inducible genes from A. thaliana
a gene was found that was originally annotated as a
tyrosine aminotransferase (TAT) (1), but was shown to be a
cystine lyase (CL) (2). Sequence similarities led to other
genes that also displayed C-S lyase activity, but a true
TAT could be isolated as well. The cDNAs for the genes
were cloned, expressed heterologously in E.coli and the
purified proteins were characterized. Expression of CL and
TAT on RNA level was assayed with semiquantitative RTPCR. While both genes were responsive to octadecanoids
the gene for cystine lyase showed a much stronger
induction. Oxidative stress generated by paraquat or
oxyfluorfen also induced the genes. The expression of the
gene for tyrosine aminotransferase, an enzyme in the
degradation pathway of tyrosine leading to tocopherol and
plastoquinone via homogentisic acid was extremely
enhanced during senescence in leaves. Tocopherol levels in
the plants were enhanced as well. Occurrence of transcripts
in different organs was assayed by using RT-PCR.
Subcellular localization of the cystine lyase and tyrosine
aminotransferase could be shown by GFP fusion constructs.
Experiments with knock-out lines have been started to look
into the physiological relevance of the enzymes.1:
Lopukhina et al, Plant Physiol 126, 1678 (2001); 2: Jones et
al, JBC 278, 10291 (2002)
P15: 5
Expression of cysteine desulfhydrases and their enzyme
activities in Brassica napus
Riemenschneider A. and Papenbrock J.
University of Hannover, Germany;
[email protected]
Brassica napus L. (oilseed rape) is one of the most
important plants for the extraction of oil used for human
diet, for technical purposes as well as a renewable energy
source. However, it is also a crop plant with high losses in
yield due to pathogen attack. High sulfur nutrition was
shown to enhance defence operations by improving general
plant performance under biotic stress. Several sulfurcontaining compounds were discussed to be involved in
sulfur-enhanced defense (SED) such as thiols,
glucosinolates, or thionins. Another defense mechanism
against pathogens might be the release of H2S. Cysteine
desulfhydrases (CDes) are able to catalyse the degradation
of cysteine to pyruvate, ammonium, and H2S or to alanine
and H2S. So CDes might play a role in plant protection. A
positive correlation of CDes activity and pathogen
infestation of Brassica was demonstrated in field
experiments indicating also differences between different
Brassica lines. Therefore different Brassica lines were
grown under different sulfur conditions in a controlled
hydroponic system and infected with fungal pathogens. The
plants were analysed for CDes mRNA accumulation and
activity as well as for their thiol content. The results are
discussed with respect to the role of desulfhydrases and
released H2S in SED.
P15: 6
Isothiocyanate concentration in Kohlrabi (Brassica
oleracea L. gongylodes) as affected by N and S nutrition
Gerendás J.1, Breuning S.2 and Mühling K.1,2
1
Institute of Plant Nutrition and Soil Science, Kiel
University, Kiel; 2Institute of Plant Nutrition, Justus Liebig
University, Giessen; [email protected]
Isothiocyanates (ITCs) have been identified in significant
quantities in Brassica vegetables and several positive
pharmacological effects have been attributed to them. ITCs
POSTER ABSTRACTS
39
P15
are formed from glucosinolates (GS, ß-thioglucoside-Nhydroxysulphates) after hydrolysis of the glycosidic bond
by myrosinase (ß-thioglucosidase), activity of which has
been discussed in relation to GS breakdown in order to
release S under S limitation. As the variable side chains of
GS are synthesized from precursor amino acids
(methionine, tryptophane in case of indolyl GS), while the
thio-glucose unit and the sulphate group are derived from
cysteine and PAPS, respectively, an interactive effect of N
and S supply on the concentration of ITCs can be
envisaged. Kohlrabi plants (cv. Lanro) were cultivated for 8
weeks in nutrient-poor soil in a 3 N (1, 2 and 4 g N pot-1)
and 3 S levels (0, 0.05 and 2 g S pot-1). Four ITCs were
identified, which occurred in largely different
concentrations (methyl-thiobutyl ITC (MTB ITC) >>
sulforaphan >> phenylethyl ITC > allyl ITC). MTB ITC
exhibited a strong interactive response to N and S supply
with positive effects of high N and low S supply, while
such interaction was less consistent for the other ITCs. In
any case, a positive association of S deprivation on ITC
concentration could not be established. In agreement,
activity of myrosinase, which has been discussed in relation
to enhanced GS breakdown under S-limited conditions, was
actually reduced at low S supply, conflicting with the
proposed function of GS as a transient S storage.
P15: 7
L-ARGININE CATABOLISM IN CYANOBACTERIA
Schriek S.1, Rückert C.2, Pistorius E.1 and Michel K.1
1
Molecular Cell Physiology, Bielefeld University; 2Institute
of Genome Research, Bielefeld University;
[email protected]
Several L-arginine degrading pathways are known in
prokaryotes. Since only little is known about the catabolism
of L-arginine in cyanobacteria, a computional analysis of
24 sequenced cyanobacterial genomes has been performed
searching for putative L-arginine degrading enzymes. With
this approach up to four possible major pathways have been
identified, and their presence in different groups of
cyanobacteria was used to describe evolutionary lineages.
In Synechocystis PCC 6803 an arginine decarboxylase, an
arginase, a L-arginine amidino transferase and a L-amino
acid oxidase/ monoamine oxidase seem to be present as the
major L-arginine degrading enzymes. We have previously
shown that a substantial difference exists in the phenotype
of Synechocystis PCC 6803 wild type (WT) and a PsbOfree mutant, when grown on L-arginine as sole nitrogen
source. In WT a mass production of cyanophycin and a
decay of cellular structures occur. In contrast, the PsbOfree mutant produces only minor amounts of cyanophycin
and the quantity of thylakoid membranes is only slightly
reduced. Observations on mRNA and protein level showed
significant changes in the subunit composition of
photosystem II and photosystem I. Furthermore differences
in the degradation of L-arginine between WT and the
PsbO-free mutant will be shown. The complex
interrelationship between L-arginine catabolism and
photosynthesis in Synechocystis PCC 6803 has been
investigated and will be discussed.
40
POSTER ABSTRACTS
P15: 8
MODULATING SEED MATURATION: NUTRIENT
STATUS AFFECTS NITROGEN METABOLISM
AND TRANSCRIPTIONAL REGULATORY
NETWORKS
Radchuk R.1, Götz K.2 and Weber H.3
1
Leibniz-Institute of Plant Genetics and Crop Plant
Research, Germany; 2Fachgebiet Pflanzenbau in den
Tropen und Subtropen, Humboldt Universität zu; 3LeibnizInstitut für Pflanzengenetik und Kulturpflanzenforschung
(IPK); [email protected]
Seed maturation responds to endogenous and exogenous
signals like nutrient status and hormones. PEP-carboxylase
over-expression in Vicia narbonensis seeds channels
carbon into organic acid synthesis resulting in greater seed
storage capacity and increased protein content. The lines
represent models with increased sink strength and
improved nutrient status. Transgenic embryos take up more
C and N. Changes in dry to fresh weight ratio, seed fill
duration and major seed components indicate altered seed
development. Array-based gene expression analysis of
seeds identified pathways responsive to metabolic and
nutrient control and underlying signalling mechanisms.
Upregulated genes during transition and late maturation
phase correspond mainly to seed metabolism, protein
storage and processing, amino acid metabolism, primary
metabolism and transport and stress tolerance, cell
proliferation and elongation, signalling and hormone
action. Stimulated cell elongation is in accordance with upregulated signalling pathways related to gibberellic
acid/brassinosteroids. We conclude that activated organic
acid production by PEPC causes wide-range activation of N
metabolism including storage protein and amino acid
synthesis, protein processing and deposition and
methylation cycle. Stimulation of arginine biosynthesis
probably occurs via a PII-like system which senses organic
acid availability. Activation of stress tolerance genes
indicates partial overlap between nutrient, stress and ABA
signals indicating a common interacting or regulatory
mechanism between nutrients, stress and ABA.
P15: 9
Protein and metabolite profiles of wheat grains from
organic and conventional agriculture
Zörb C.1, Betsche T.1, Niehaus K.1, Barsch A.2 and
Langenkämper G.1
1
Bundesforschungsanstalt für Ernährung und Lebensmittel,
Detmold, Germany; 2Lehrstuhl für Genetik, Universität
Are there biochemical differences detectable when organic
products are compared with their conventional counterparts
under rigid experimental conditions? We conducted
metabolite and protein profiling of organically vs.
conventionally produced wheat. Because production site,
cultivar and harvest conditions are different if
commercially produced wheat is investigated, wheat (cv.
Titlis) grown in 2005 under the very well controlled
conditions of the long term biodynamic, bioorganic and
conventional field trial DOK in Switzerland was analysed.
Using two dimensional gel electrophoresis and gas
chromatography mass spectrometry, expression levels of
proteins and a set of metabolites including amino acids,
organic acids, sugars, sugar alcohols, sugar phosphates, and
nucleotides from wheat grains were determined. Statistical
analyses of relative concentrations of metabolites showed
that 44 out of 52 metabolites were identical between
P15/P16
organic and conventional agriculture. Within a group of 8
unrelated metabolites statistically significant changes up to
50% were observed depending on farming system. Protein
profiles of the wheat grains, recorded by 2D-gel
electrophoresis, also revealed a considerable number of
proteins the expression levels of which were significantly
different between wheat produced organically vs.
conventionally. Notably expression levels of proteins very
high in N, e.g. glutenins, were lower in organic wheat.
P15: 10
Regulation of methionine recycling in plants
Bürstenbinder K. and Sauter M.
Botanisches Institut, Universität Kiel, Germany;
[email protected]
S-adenosylmethionine, the activated form of methionine
(Met) serves as substrate for the synthesis of ethylene,
polyamines and phytosiderophores. As a by-product, 5methylthioadenosine (MTA) is released which is recycled
to Met via the Met cycle. We identified genes encoding
Met cycle enzymes from Oryza sativa L. and Arabidopsis
thaliana. We showed that OsARD1 from rice was
upregulated as an immediate-early response to
submergence or ethylene treatment. By contrast, Met cycle
genes in Arabidopsis were not regulated by ethylene. We
hypothesize that regulation of Met cycle genes by ethylene
may be restricted to plants with natural phases of high and
prolonged ethylene synthesis such as semiaquatic plants or
climacteric fruits. In Arabidopsis, expression of Met cycle
genes was not altered when sulfur was supplied as Met or
MTA rather than sulfate. Supply of MTA did however
induce enzyme activity of MTA nucleosidase indicating
that regulation can occur at the posttranscriptional level.
Arabidopsis mutants in which conversion from MTA to
methylthioribose was interrupted showed delayed flower
development. Knock-out of methylthioribose kinase which
catalyzes the subsequent reaction did not affect
development. These different mutant phenotypes indicate
that disturbed MTA metabolism rather than Met supply
affected plant development. Accumulation of MTA may
alter polyamine and/or ethylene synthesis and consequently
plant development.
P15: 11
RNAi-technology in poplar
Popko J., Oelkers M., Kuchernig J., Meyer S., Mendel
R. and Hänsch R.
Department of Plant Biology, Technical University of
Braunschweig, Germany; [email protected]
The potential of RNA interference (RNAi) technology is
studied for down regulation of gene expression in poplar. A
set of vectors was constructed generating RNAs capable of
duplex formation for molybdoenzymes and for the
calibration-system ß-glucuronidase. These gene cassettes
are driven by the CaMV-35S-promoter and contain spacer
segments of different origins and lengths. We tested the
functionality of the vectors in the GUS-reporter gene assay,
both in transient assays and in stably co-transformed GUSexpressing poplar plants. From these results we can
conclude that RNAi is functional in poplar. In parallel, we
used the most efficient RNAi-vectors for down regulation
of two molybdoenzymes (nitrate reductase and aldehyde
oxidase) and the molybdenum cofactor-sulfurase ABA3.
Whereas in the GUS-calibration-system the gene-silencing
was highly effective with residual enzyme activities below
1%, for nitrate reductase activity only 50% reduction could
be achieved in the tested lines of P. x canescens.
P15: 12
The effect of nitrate on starch degradation in Spirodela
turions
Ziegler P.1 and Appenroth K.2
1
Department of Plant Physiology, Universität Bayreuth,
Germany; 2Institute of General Botany and Plant
Physiology, Universität Jena, Germany; [email protected]
Light induces the germination of turions of the duckweed
Spirodela polyrhiza and the degradation of the reserve
starch stored in the turions. Both the germination
photoresponse and the light-induced starch degradation are
dependent upon nitrate. Whereas ammonium can substitute
for nitrate in germination, it cannot do so in starch
degradation. Nitrate thus acts as a specific signal to
promote starch degradation in the turions. The perception
of continuous red light by phytochrome results in autophosphorylation of starch-associated glucan-water dikinase
in the turions. This phosphorylates the starch, which is
accompanied by an enhanced binding of alpha-amylase to
the starch granules and the onset of starch breakdown. The
results of the present study show that all of these processes
require the presence of nitrate, and that nitrate thus exerts
its effect on starch degradation at the step between the
absorption of light by phytochrome and the autophosphorylation of the glucan-water dikinase. The fact that
nitrate also regulates several enzymes of nitrogen
assimilation shows that nitrate acts to coordinate carbon
and nitrogen metabolism in germinating Spirodela turions.
P16: OBSERVATION OF
DESERTIFICATION
P16: 1
Population Analysis as Indicator for Processes of
Degradation
Augustin A. and Finckh M.
BIOTA Maroc, Germany; [email protected]
Degradation of arid ecosystems in Africa is generally
caused by extensive land use. Some degradation processes
are slow and disguised by interannual climatic fluctuations
and therefore difficult to detect. Vegetation surveys based
on species inventories and cover are snap-shots in time and
thus often insufficient to analyse degradation processes.
Instead, population analysis is a more suitable tool for
detecting and monitoring processes of change.
In this study, change is monitored in the semiarid ecotones
of Southern Morocco with experimental sites along a
transect. The influence of land use, in this case grazing and
firewood extraction, is investigated using pairs of open and
fenced plots. After six years of monitoring, diverging
population structures of key species on the test sites can be
observed, demonstrating the influence of land use.
Observed population parameters include regeneration,
establishment and die off events as well as annual growth
rates and vitality parameters for every individual. These
data allow to deduct age class distributions, growth
functions and mortality rates. Therefore, deep insight into
population dynamics and underlying ecological processes is
POSTER ABSTRACTS
41
P17
P17: ORGANELLES
In contrast to Alb3 we could not detect any interaction of
Alb4 with the components of the cpSRP in the split-YFP
system. Thus, Alb4 seems not to be directly involved in the
posttranslational cpSRP transport pathway.
1.
Gerdes, L., Bals, T., Klostermann, E., Karl, M.,
Philippar, K., Hunken, M., Soll, J., and Schünemann, D.
(2006) J Biol Chem 281, 16632-42
P17: 1
P17: 3
gained, such as overaging induced by high grazing pressure
or recolonisation under exclosure conditions. Changes in
population structures are thus suitable indicators for
changing environmental conditions in ecosystems.
A substrate-independent, 14-3-3 protein mediated
plastid import pathway of NADPH:protochlorophyllide
oxidoreductase A
Reinbothe C.
Universite Joseph Fourier, France;
[email protected]
Plastids are semiautonomous organelles which must import
the major part of their protein constituents from the cytosol.
The exact role of cytosolic targeting factors in the
regulation of plastid protein import has not been
determined. Here we report that the nucleus-encoded
NADPH:protochlorophyllide (Pchlide) oxidoreductase A
plastid precursor (pPORA) can use two different plastid
import pathways which differ by the requirements for
cytosolic 14:3:3 proteins and Hsp70. pPORA synthesized
in a wheat germ lysate segregated into different precursor
fractions. While import of free pPORA and only Hsp70complexed pPORA was Pchlide-dependent and involved
the previously identified Pchlide-dependent translocon,
14:3:3 protein- and Hsp70-complexed pPORA was
transported into Pchlide-free chloroplasts through the
Toc75-containing standard Toc/Tic machinery. A 14:3:3
protein binding site was identified in the mature region of
the 35S-pPORA which governed 14:3:3 protein- and Hsp70mediated, Pchlide-independent plastid import. Collectively,
our results reveal that the import of pPORA into the
plastids is tightly regulated and involves different cytosolic
targeting factors and plastid envelope translocon
complexes.
P17: 2
Analysis of Alb3 and Alb4 in protein integration into
the thylakoid membrane
Bals T. and Schünemann D.
Ruhr-Universität Bochum, Germany; [email protected]
The thylakoid membrane proteins Alb3 and Alb4 belong to
the evolutionary conserved Alb3/Oxa1/YidC family whose
members facilitate protein integration into membranes of
chloroplasts, mitochondria and bacteria. Alb3 is essential
for the integration of light-harvesting chlorophyll-binding
proteins (LHCP) into the thylakoid membrane. Analysis of
the chloroplast ultrastructure of Arabidopsis mutants
containing reduced levels of Alb4 indicate that Alb4 is also
required for proper chloroplast biogenesis (1). But nothing
is known yet about the precise function of Alb4.
We use the bimolecular fluorescence complementation
technique (split-YFP) for testing potential interaction
partners of Alb3 and Alb4 in their natural environment. By
using the split-YFP system we could show the interaction
of Alb3 with cpSRP43, whereas there was no interaction of
Alb3 with cpSRP54 or cpFtsY. Therefore, the docking of
the transit complex, consisting of cpSRP43, cpSRP54 and
LHCP, and the integration of the LHCP into the thylakoid
membrane might be facilitated via the interaction of Alb3
and cpSRP43. In further studies we try to determine the
binding sites of these two proteins by using the split
ubiquitin system.
42
POSTER ABSTRACTS
Analysis of possible Alb3.2p functions in
Chlamydomonas reinhardtii chloroplasts
Piekenhayn S. and Ossenbühl F.
Molekulare Botanik, Universität Ulm, 89069 Ulm,
In chloroplasts, members of the YidC/Oxa1p/Alb3 protein
family are necessary for the functional assembly of
photosynthetic complexes in the thylakoid membrane. In
Synechocystis, the Alb3 homolog SynOxa1p enables the
insertion of D1 into the thylakoid membrane and
photosystem (PS) II. The green algae Chlamydomonas
reinhardtii encodes two Alb3 homologs, Alb3.1p and
Alb3.2p. The latter, Alb3.2p, is essential for cell growth
even under heterotrophic conditions, suggesting additional
functions for this protein besides a role in the assembly of
photosynhetic complexes. Previously, several interaction
partners of Alb3.2p have been identified by coimmunoprecipitation (CoIP), including Alb3.1p and
subunits of PS I and II. In addition, Alb3.2p also interacts
with VIPP1 (vesicle-inducing protein), which might be
involved in lipid transfer and plastid vesicle formation.
Since the results indicate an Alb3.2p participation in yet
unknown essential cellular pathways other than PS
assembly, we have initiated a detailed analysis of the
Alb3.2 protein to get new hints for these functions. Firstly,
we investigated the localisation of Alb3.2p within the
thylakoid membrane. Secondly, we have optimized the
CoIP assay with Alb3.2p and are currently identifying
interacting proteins by HPLC/MS. Thirdly, to address
whether these novel interactions are direct or indirect, we
performed cross-link experiments. Currently initiated are
assays with Alb3.2 RNAi mutants which will be
investigated for additional Alb3.2p functions in
chloroplasts of Chlamydomonas reinhardtii.
P17: 4
Analysis of the biogenesis of LHC-proteins in
Chlamydomonas reinhardtii and higher plants
Richter C. and Schünemann D.
Ruhr-Universität Bochum, Germany;
[email protected]
The cytosolic SRP pathway is involved in the
cotranslational protein transport to the ER membrane in
eukaryotes and to the plasma membrane in bacteria.
Cytosolic SRPs contain at least an RNA component and a
54 kDa subunit (SRP54). The chloroplast SRP (cpSRP) is
responsible for the posttranslational targeting of nuclear
encoded light-harvesting chlorophyll-binding proteins
(LHCPs) to the thylakoid membrane. The cpSRP of higher
plants does not contain an RNA component, but in addition
to a SRP54 homologue (cpSRP54) it also contains a 43 kDa
subunit (cpSRP43) (1). Interestingly, in Chlamydomonas a
cpSRP54 homologue was found but neither a SRP-RNA
component (2) nor an obvious cpSRP43 homologue has yet
been identified by in silico studies. These findings raise the
question after the LHCP integration mechanism in
Chlamydomonas.
P17
Recently, it has been shown that a 10-amino acid long
segment located close to the C-terminus of cpSRP54 of
higher plants forms the cpSRP43-binding site. Even though
the motif in the Chlamydomonas cpSRP54 shows high
sequence similarity to the cpSRP43-binding site of higher
plants we demonstrated that Chlamydomonas cpSRP54
cannot bind to Arabidopsis cpSRP43.
In Chlamydomonas, we identified a protein, with low
sequence similarity but high structural similarity to the
cpSRP43 of higher plants. In further studies we try to
analyse the function of this protein and whether it is a
component of the cpSRP in Chlamydomonas.
1. Schünemann, D. (2004) Curr Genet 44, 295-304
2. Rosenblad, M. A., and Samuelsson, T. (2004) Plant Cell
Physiol 45, 1633-1639
P17: 5
Biochemical characterization of two DEAD-box
proteins in mitochondria of Arabidopsis thaliana
Köhler D., Matthes A. and Binder S.
Molekulare Botanik, Universität Ulm, Germany;
[email protected]
DEAD-box proteins participate in virtually all processes of
the RNA metabolism as for instances translation initiation
or ribosome biogenesis. Some of them have RNA helicase
activity exhibiting RNA-dependent ATPase and NTPdependent RNA unwinding activity. In A. thaliana nothing
is known about the functions of DEAD-box proteins and
their potential role in the mitochondrial RNA metabolism.
We investigate two mitochondrial members of the DEADbox protein family of A. thaliana PMH1 and 2, for putative
mitochondrial RNA helicase. They share 77% identical
amino acids. So for biochemical analysis we used an
antibody detecting both proteins. Immunodetecting after
2D Blue native/SDS PAGE or separation on sucrose step
gradients of total mitochondrial protein we found one or
both proteins to be part of RNA-dependent high molecular
weight complexes. These complexes can be stabilized by
cold treatment of the cell suspension culture prior to
isolation of mitochondria or by addition of MgCl2 during
protein solubilization. To investigate a possible function of
PMH1 and 2 in ribosome biogenesis or translation we
compared the distribution of ribosomal RNA representative
for polysomes or monosomes with that of PMH1 and 2 in
sucrose step gradients under various conditions. While the
protein complexes can be dissociated by addition of KCl
during protein solubilization, ribosomes or polysomes
remained unaffected. Thus the two DEAD-box proteins
seem to be not stably associated with ribosomes suggesting
another as yet unknown function of these proteins.
P17: 6
Characterising the multitude of chloroplast protein
import receptors in Arabidopsis thaliana
Gutensohn M. and Hust B.
Institut für Biologie - Pflanzenphysiologie, MLU HalleWittenberg, Germany; [email protected]
The majority of chloroplast proteins are encoded in the
nucleus and have to be imported into the organelle after
their synthesis in the cytosol as precursor proteins. The
transport of precursors across the two chloroplast envelope
membranes is mediated by the interaction with two import
machineries, the Toc and Tic complex. The core of the Toc
complex consists of two receptor proteins, Toc34 and
Toc159, involved in initial binding of precursor proteins at
the chloroplast surface and a translocation pore, Toc75. In
Arabidopsis two homologs of Toc34 (atToc33, atToc34)
and four homologs of Toc159 (atToc159, atToc132,
atToc120, atToc90), however, only one ortholog of Toc75
(atToc75-III), have been identified. For the functional
characterisation we have isolated knockout mutants for all
six Arabidopsis Toc receptors as well as for the
translocation pore. The atToc75-III knock out mutant has
an embryo lethal phenotype with an extremely early arrest
of development. In contrast, the Toc receptor mutants show
remarkably different phenotypes suggesting more
specialized functions for these import receptors. Detailed
characterisation of the Toc receptor mutants, including
proteome and expression analyses, as well as in vitro
studies demonstrated that each of these Toc receptors
preferentially interacts with different groups of precursor
proteins. The composition of Toc complexes in Arabidopsis
has been analysed by biochemical approaches using
specific antibodies as well as by a genetic approach using a
series of Toc receptor double mutants.
P17: 7
Cyclophilin Cyp 20-3 is involved in plastidic redox
homeostasis
Kandlbinder A., Laxa M. and Dietz K.
University of Bielefeld, Germany;
[email protected]
Due to an unavoidable production of reactive oxygen
species (ROS) in the context of photosynthesis, plants
require an efficient defence system to balance ROS
concentrations and avoid oxidative damage. The redox
regulated thiol-disulfide protein system of plants is a
defense network against ROS as well as a regulatory
system comprised of enzymes like thioredoxins,
peroxiredoxins, glutaredoxins and as well cyclophilins
(Cyps).
Cyclophilins (Cyps) are a class of highly conserved,
ubiquitous proteins of the immunophilin superfamily that
have been suggested to play key roles in a number of
cellular responses including protein folding, protein
degradation, stress response and signal transduction.
Conserved Cys-residues further suggest a role in redox
regulation. The rather negative midpoint redox potential of
-319 mV places Cyp 20-3 into the redox hierarchy of the
chloroplast suggesting the activation of Cyp 20-3 in the
light under conditions of limited acceptor availability for
photosynthesis as realised under environmental stress. In
order to get insight into the conformational change
mechanism and functional properties of the chloroplast
located Cyp 20-3, site-directed mutagenised Cys→Servariants were generated and analysed for enzymatic and
conformational properties under reducing and oxidising
conditions. Current experiments employing Cys→Servariants in affinity chromatography assays aim at
identifying putative target proteins of Cyp 20-3 in order to
deepen our understanding of its specific function in
plastidic redox homeostasis, chloroplast regulation and
development.
P17: 8
Dual localization of the Whirly 1 protein in plastids and
nucleus
Grabowski E., Miao Y., Mulisch M., Kilbienski I. and
Krupinska K.
CAU Universität zu Kiel, Germany; [email protected]
POSTER ABSTRACTS
43
P17
Whirly 1 is a single stranded DNA binding factor which
has a molecular weight of about 24kDa (1). Why1 belongs
to a recently described protein family, so far only found in
angiosperms. While in most plant species two members
were found, Arabidopsis thaliana has three of them (2). All
members of the Whirly protein family have the
characteristical domain KGKAAL in common which is
involved in binding to DNA. The first Whirly protein
which was described is p24 from potato, renamed StWhy1.
This protein is a subunit of the complex PBF-2 which has a
function as a transcriptional factor (1). Crystallographic
analyses showed that four p24 monomers form a tetramer
(3) and bind single stranded DNA, specially on an elicitor
response element (ERE) in the promoter region of the
PR10a gene (1) as well as to the telomeric heptanucleoide
TTTAGGG. A T-DNA insertion knockout mutant was
shown to possess longer telomeres suggesting that
AtWHY1 inhibits telomerase activity (4). In contrast to the
already described functions in the nucleus it was shown
that the Why1 protein from Arabidopsis thaliana is targeted
to the plastid (2). A specific antibody was produced to
investigate the subcellular localisation of the native
HvWhy1 protein.
References:
(1) Desveaux D, Deprés C, Joyeux A, Subramanian R,
Brisson N (2000) Plant Cell 12:1477-1489
(2) Krause K, Kilbinski I, Mulisch M, Rödiger A, Schäfer
A, Krupinska K (2005) FEBS Lett. 579: 3707-3712
(3) Desveaux D., Allard J., Brisson N., Sygusch J. (2002)
Acta Cryst.D58, 296-298
(4) Yoo H.H., Kwon C., Lee M.M., Chung I.K. (2007)
Plant Journal 49: 442-451
P17: 9
Dual targeting – Organelle specificity of nuclear
encoded proteins
Rödiger A., Baudisch B. and Klösgen R.
Martin-Luther-University Halle-Wittenberg, Germany;
[email protected]
Most mitochondrial and chloroplast proteins are encoded in
the nucleus and synthesised in the cytosol as precursors
carrying signals mediating transport into the target
organelle. Generally, such targeting signals are specific for
a single organelle only, i.e. either mitochondria or
chloroplasts. But more and more proteins are identified that
show dual targeting into both organelles.
In order to identify candidates for dual transport, protein
import experiments are performed with isolated
mitochondria and chloroplasts in single organelle as well as
mixed organelle assays. Such in vitro experiments are
complemented by in vivo analyses in which genes encoding
fluorescent reporter proteins fused to the putative dual
targeting signals are transiently expressed in plant tissue
after particle bombardment. Subsequent fluorescent
microscopy of the transformed tissue allows to determine
the subcellular localisation of the proteins within living
plant cells.
It is the final goal of these experiments to examine the
impact of dual targeting on the functional coordination of
the organelles within the plant cell.
44
POSTER ABSTRACTS
P17: 10
Evolution and Regulation of the Higher Plant
Chloroplast Transcriptome
Stoppel R., Cho W., Geimer S., Lezhneva L.,
Schwenkert S. and Meurer J.
Department Biologie I, Botanik, LMU, Munich, Germany;
[email protected]
Chloroplast mRNA metabolism is integrated into wider
gene regulatory networks. To explore how, we performed a
chloroplast genome-wide and nuclear expression analysis
on wild-type Arabidopsis plants subjected to various
stresses and nuclear mutants affected in chloroplast
functions. Knowledge about this regulation is not only
increasingly relevant for basic research studies but also for
applying transplastomic approaches in agriculturally
important plants. Surprisingly, phytochrome-mediated
effects on plastid gene expression are more extensive and
occur much faster than those on nuclear genes during early
seedling de-etiolation. Plastid genes could be divided into
two oppositely regulated clusters largely congruent with the
targets of nucleus- and plastid-encoded RNA polymerases,
respectively. Chloroplast transcriptomes were classified
into two major groups, comprising mutants preferentially
affected in plastid gene expression and other chloroplast
functions, respectively. Novel nuclear genes putatively
relevant for photosynthesis and mutants impaired in
chloroplast RNA metabolism were identified. Several
newly discovered nuclear genes, CRP135, HCF145,
CRP102, and CRP106, required for cleavage, stability and
splicing of plastid mRNAs are exclusively present in higher
plants. Overall, our data demonstrate that integration of
chloroplast mRNA metabolism into the ontogenetic
program of the plant cell represents a fast evolving process
and was established by recruiting nucleus-encoded factors
to control and coordinate plastid and nuclear gene
expression.
P17: 11
Ferritins – organelle targeting and assembly of iron
storage proteins in plants
Hoffmann M. and Klösgen R.
Institute of Biology, Martin-Luther-University HalleWittenberg, Germany;
[email protected]
Ferritins are iron storage proteins involved in iron
homeostasis, that are found in almost all organisms
including plants, bacteria and mammals. In plants, they are
assumed to be exclusively localised in chloroplasts,
although there is some evidence for the presence of ferritins
in plant mitochondria (Zancani et al., Eur. J. Biochem, 271,
2004).
The nuclear genome of Arabidopsis thaliana, houses four
genes encoding ferritin. In order to analyse organelle
targeting and assembly of these four ferritins, in vitro
import assays with isolated organelles were performed.
Both, single and mixed organelle assays were applied and
the proteins were subsequently analysed by SDS-PAGE
and Blue Native-PAGE respectively. As a complementary
approach, in vivo targeting analyses in which suitable
fluorescent reporter fusions of these ferritins were
transiently expressed in plant cells after particle
bombardment. Recent data of these analyses will be
presented.
P17
P17: 12
From seedling to mature plant: the ups and downs of
organellar genomes
Liere K., Preuten T., Zoschke R. and Börner T.
Humboldt-Universität zu Berlin, Institut für Biologie /
Genetik, Germany; [email protected]
As one of the defining aspects of plants, plastids are present
in virtually all cells. They accomplish important metabolic
functions and exist in different types with specialized roles.
Each plastid in a plant contains identical, circular plastome
copies. In addition to monomeric circles, dimers, trimers
and tetramers exist, as well as linear and more complex
molecules of different sizes.
The genome of plant mitochondria does not occur as a
master circle, but exists in numerous circular and linear
molecules of different sizes. Mitochondria in higher plants
steadily undergo fusion and fission events, thereby
exchanging proteins, RNA and DNA molecules.
Chondromes are not identical in size and content, in fact
DNA contents variegate broadly between individual
mitochondria.
However, little is known about DNA metabolism during
leaf development and aging in the model organism
Arabidopsis. Therefore, we examined nuclear, plastidial
and mitochondrial DNA contents in tissue ranging from 2day old cotyledons to 37-day old senescent rosette leaves.
Analysis of plastidial nucleic acid metabolism revealed
constant DNA levels but distinct RNA levels and
transcription rates during Arabidopsis plant development
and aging. However, chondrome copy numbers varied from
about 40 to 350, thus being notably below the predicted
number of about 500 mitochondria per cell. Our data
suggest differential amplification of subgenomic molecules
in mitochondria and reveal the importance of an integrative
chondriome in higher plant cells.
P17: 13
Group II intron-binding proteins, components of the
putative chloroplast spliceosome in Chlamydomonas
reinhardtii
Glanz S., Balczun C. and Kück U.
Ruhr-Universität Bochum/ LS für Allgemeine und
Molekulare Botanik, German; [email protected]
The unicellular green alga C. reinhardtii is widely used for
analyzing intron-binding proteins that are mainly encoded
by the nuclear genome and are thought to promote the
maturation of chloroplast precursor RNAs. As an example,
the expression of the psaA gene, in particular the transsplicing process of its precursor RNAs was studied. Here,
we present two biochemical approaches that enable the
isolation of two novel nuclear-encoded factors showing
specific binding properties to organelle group II intron
RNA.
In the first approach, a 61-kDa chloroplast RNA-binding
protein was isolated and identified by FPLC
chromatography and mass spectrometry as the chloroplast
heat shock protein Cpn60. Recombinant Cpn60 was used in
RNA electrophoretic mobility shift assays (EMSA) and
these analyses revealed that its ATPase domains mediate
the specific binding of two group II intron RNAs derived
from the homologous psaA gene and the heterologous
mitochondrial LSU rRNA gene. In the second approach,
the yeast three-hybrid system was used to isolate the
chloroplast nucleosome assembly protein-like cNAPL. The
RNA-binding property was demonstrated by EMSA as
mentioned above. The chloroplast localization of cNAPL
was determined by laser scanning confocal fluorescence
microscopy. Phylogenetic analysis showed that no
homologues of cNAPL and its related counterparts are
present in prokaryotic genomes. The function of Cpn60 and
cNAPL as general organelle splicing factors will be
discussed.
P17: 14
Immunological detection of NEP (nuclear encoded RNA
polymerase) in trancriptionally active fractions derived
from barley (H. vulgare) chloroplasts
Melonek J., Schmitz B., Müller L. and Krupinska K.
CAU Kiel, Germany; [email protected]
The transcriptional apparatus of chloroplasts can be
isolated in two biochemical distinguishable fractions (1).
One of them is the transcriptionally active chromosome
(TAC) which is tightly bound to the plastid DNA and
attached to thylakoid and envelope membrane. The other
active fraction referred to as soluble enzyme sRNAP can be
easily released from the plastid DNA by high salt
concentration. While transcriptional activity of the sRNAP
depends on the addition of exogenous DNA, the RNApolymerase in TAC elongates transcripts that have already
been initiated in vivo. The plastid encoded RNA
polymerase (PEP) is detectable in both fractions (2). So far,
the nuclear encoded RNA polymerase (NEP) has not been
detected in these. We were able to immunologically detect
the NEP in a sRNAP fraction isolated from barley
chloroplasts. However, no signal was obtained with highly
purified TAC- extracts.Further attempts to elucidate the
composition of these two chloroplast fractions are
presented. In the case of the TAC, recent investigations on
its protein composition by immunological analyses (3) and
two-dimensional gel electrophoresis are presented. In the
case of sRNAP, developmental- and circadian-depended
changes in transcription pattern of several plastid genes
were observed.
References:1. Kössel et al. (1992) Crit Rev Plant Sci 10:
525- 5582. Krause and Krupinska (2000) Physiol Plant
109: 188-1953. Da Costa e Silva et al. (2004) Plant J 38:
923- 939
P17: 15
In organello analysis of cauliflower and maize
mitochondrial editing
Kempken F. and Bolle N.
Botanisches Institut, Christian-Albrechts-Universität zu
Kiel, Germany; [email protected]
Gene expression in plant mitochondria involves
posttranscriptional events like splicing and editing of the
transcripts. RNA editing in plant mitochondria is a process
that alters the genetic information by mainly C-to-U
exchanges and rare U-to-C exchanges. Yet, little is known
about the biochemistry and the mechanism of RNA editing
in plant mitochondria. To analyse plant mitochondrial RNA
processing we used an established method to introduce
foreign DNA into maize and cauliflower mitochondria. In
organello incubation of the mitochondria in a specific
buffer system allows transcription and processing of the
transcripts. Using this system, we have shown that
transcripts from introduced Arabidopsis thaliana cox2 and
Zea mays cox2 are spliced and edited efficiently in maize
and cauliflower mitochondria. Interestingly, the editing
sites not present in the endogenous cox2 transcripts were
fully edited in the heterologous cox2 transcripts, but no
additional site was edited. Furthermore we introduced point
POSTER ABSTRACTS
45
P17
mutations in the cox2 gene of Arabidopsis thaliana,
creating maize-specific cox2 editing sites in the respective
transcripts. In organello analysis of these transcripts
showed fully editing of the introduced editing sites in
maize mitochondria. Further analyses are necessary to
better understand how recognition specificity of RNA
editing sites works in plant mitochondria.
P17: 18
P17: 16
in vivo silencing screen aiming to obtain molecular
information about structure and regulation of
chloroplast protrutions
Schattat M.1, Hauer R.1, Schornack S.2 and Klösgen R.1
1
Pflanzenphysiologie, Martin Luther Universität Halle
Wittenberg, Germany; 2Genetik, Martin Luther Universität
Halle Wittenberg, Germany;
[email protected]
Detailed analysis of plants expressing chimeric proteins
consisting of chloroplast targeting transit peptides fused to
fluorescent proteins such as GFP led to the (re)discovery
of stromules (stroma filled tubules) which temporarily
protrude from the surface of plastids and which in rare
cases can even connect two individual organelles. They are
enclosed by the outer and inner envelope membrane and
can be of different shape and length. Stromules have been
identified in all plastid types and plant species examined so
far and occur apparently in all cell types. The frequency of
their occurence varies from tissue to tissue, and they are
furthermore highly dynamic structures. In general, they
occur more frequently in cells containing non-green
plastids. By the use of drugs such as cytochalasin and
latrunculin which inhibit actin and tubulin it could be
shown that the formation and inheritance of stromules is
dependent on a functional actin cytoskeleton. On the other
hand, knowledge about the structural components and the
primary function of stromules as well as about the genetic
background of their regulation is still very limited. We have
therefore initiated an in vivo silencing screen aiming to
obtain molecular information about the structure as well as
the regulation of stromules in plant cells. First results of
this approach will be presented.
P17: 17
Insights into plant mitochondrial RNA editing
Bolle N. and Kempken F.
Universität zu Kiel, Bot. Institut, Olshausenstraße 40,
24098 Kiel, Germany; [email protected]
To understand RNA editing systems in higher plants we
study in organello transcription of mitochondrial and
plastid genes, employing a recently established system of
electroporation and in organello incubation of
mitochondria. We introduced the Zea mays and the
Arabidopsis thaliana cox2 genes into cauliflower and
maize mitochondria, respectively, and analysed editing of
the transcripts. Surprisingly, both the mono- and
dicotyledonous cox2 transcripts were efficiently edited in
the mitochondrial in organello systems, even for RNA
editing sites not present in the endogenous cox2 sequences.
Database searches revealed the presence of mono- and
dicotyledonous-specific RNA editing sites. Taken together
our observations support a self-guiding-transcript model for
RNA editing in mitochondria of higher plants.Furthermore
we used the in organello system to analyse RNA editing of
plastid open reading frames in mitochondrial background.
To this end we fused the plastid ndhB and the ycf3 coding
sequences from maize with two different mitochondrial
46
promoter sequences. These constructs were then introduced
into maize and cauliflower mitochondria, and RNA
processing was studied. The transcripts were neither
spliced, nor edited, indicating that organelle-specific
editing factors exist. Currently, the splicing and editing of
chimeric ndhB genes is underway.
POSTER ABSTRACTS
Integration of photosynthetic proteins into the thylakoid
membrane
Sikorski M.1, Piekenhayn S.1, Schuenemann D.2 and
Ossenbühl F.1
1
University Ulm, Germany; 2University Bochum,
During photosynthesis photosystem (PS) II and in
particular the reaction center protein D1 is damaged by
reactive oxygen species. Due to this photoinhibition, D1
has a high turn-over rate. This includes the removal and
degradation of the inactivated D1 and its functional
replacement by a newly synthesized, integrated and folded
D1. The protein SynOxa1p (Slr1471p) has recently been
shown to be required for integration, folding and assembly
of D1 into thylakoid membranes. Co-immunoprecipitation
(CoIP) suggests an interaction of D1 with SynOxa1p. To
identify and characterize a possible direct interaction of D1
with SynOxa1p in more detail we initiated respective
experiments with the yeast split-ubiquitin-system. Assays
with this system indeed identified a direct interaction of D1
with SynOxa1p. To locate the interaction site(s) we
generated D1-fragments covering various regions of the
active D1 protein. The data obtained suggest two putative
interaction sites within the N-terminal half of D1. Since the
results of the split-ubiquitin-system are derived in a
heterologous system (yeast) we set out to verify the data by
analyzing the interaction of D1 with SynOxa1p in
Synechocystis. We therefore isolated polysomes and found
that SynOxa1p co-fractionates with polysomes. CoIPs of
radioactively labeled polysomes of Synechocystis with
antibodies against D1 demonstrated an interaction of
SynOxa1p already with nascent chains of D1. In summary
we conclude that D1 integration into thylakoid membranes
occurs co-translationally with SynOxa1p as essential,
membrane integral chaperone.
P17: 19
Intramembrane proteolysis: mitochondrial rhomboids
of yeast and Arabidopsis
Stohn P.1, Krumpe K.1, Schumacher B.1, Janska H.2 and
Pratje E.1
1
Universität Hamburg, Germany; 2University of Wroclaw,
Poland; [email protected]
Rhomboid proteases are conserved in all kingdoms of
organisms and control a wide range of cellular functions
and developmental processes by intramembrane
proteolysis. They comprise a class of integral membrane
proteins with six or seven transmembrane helices.
In yeast the rhomboid protease Pcp1 is located in the
mitochondrial inner membrane. It catalyses the second step
in the proteolytic processing of cytochrome c peroxidase, a
mitochondrial enzyme that acts as a peroxide scavenger. By
processing its second known substrate Mgm1, a dynaminrelated GTPase, Pcp1 also influences the morphology of
mitochondria.
The amino acid residues contributing to the catalytic sites
are located in different transmembrane domains and are
highly conserved in the rhomboid proteins known to reside
P17
in mitochondria. The proteolytic activity of the Pcp1
rhomboid protein is abolished by deletions of various
transmembrane domains, whereas its integration into the
inner mitochondrial membrane is not affected.
Thirteen rhomboid-like proteins were identified in the
Arabidopsis thaliana databases by sequence comparison.
Putative mitochondrial targeting sequences were predicted
for five of them.
Expression of these five Arabidopsis rhomboid genes in the
yeast pcp1 deletion mutant indicates that these rhomboids
do not recognize the yeast substrate cytochrome c
peroxidase. Our data suggests diversity in substrate
recognition mechanism among mitochondrial rhomboids.
P17: 20
LOCALIZATION OF OPPP ENZYMES USING
FLUORESCENT REPORTER PROTEINS
Meyer T. and von Schaewen A.
Westfälische Wilhelms-Universität Münster, Germany;
[email protected]
We are studying the role of OPPP (oxidative pentosephosphate pathway) enzymes in higher plants that reside in
different cellular compartments and are known to act at the
junction of primary and secondary metabolism. The
complete sequence of OPPP enzymes is found in plastids as
a formal reversion of the Calvin cycle and ensures NADPH
production and phosphorylated sugar intermediates for
anabolic synthesis during the night. There is evidence that
in the cytosol of plant cells only the first 3 oxidative steps,
namely Glucose-6-phosphate-dehydrogenase (G6PDH), 6Phosphoglucono-lactonase
(6PGL),
and
6Phosphogluconate-dehydrogenase (6PGDH) up to Ru5-P
occur (which can be imported into plastids via a XyluloseP-transporter; see Schnarrenberger et al. 1995). Our data
show that the oxidative branch of the OPPP is also present
in microbodies, as suggested previously by biochemical
evidences (Corpas et al. 1998). A bioinformatic database
search of the Arabidopsis genome revealed two OPPP
enzymes with peroxisomal targeting signals (PTS I class) at
their C-termini (Reumann et al. 2004), one 6PGL isoform
(ending -SKL) and one 6PGDH isoform (ending -SKI). To
facilitate co-expression studies, we created various fusions
with flourescent protein variants, and confirmed their
localization experimentally. Among all Arabidopsis
G6PDH isoforms there was none with either obvious Cterminal PTS I or N-terminal PTS II signal. Thus, we
designed constructs in which the fluorescent protein resides
also in the centre of all plastidial predicted G6PD isoforms.
P17: 22
Protein integration into the inner envelope membrane
of chloroplasts
Ladig R., Janssen F., Gutensohn M. and Klösgen R.
Institut für Biologie - Pflanzenphysiologie, MLU HalleWittenberg, Germany; [email protected]
The majority of chloroplast proteins is encoded in the
nucleus and synthesized in the cytosol as precursor proteins
with transit peptides which are responsible for the targeting
of precursor proteins to and into the organelle. While the
translocation of proteins across the envelope membranes
into the stroma and subsequent targeting of proteins to the
thylakoids has been studied very well, little is known about
the insertion of proteins into the inner envelope membrane
of chloroplasts.
Since the inner envelope represents an important
physiological barrier between the organelle and the cytosol,
it contains many membrane proteins involved in the
transport of sugars, lipids, co-factors, ions, etc. Most of
these proteins are polytopic membrane proteins with
multiple membrane spans. The insertion mechanism of
these proteins into the inner envelope of plastids is
essentially unknown. To gain more insight into this topic,
authentic as well as mutated or recombinant inner envelope
proteins are analysed using in vitro import assays in
combination with denaturing SDS-PAGE and native BNPAGE. Among the proteins examined are HP26b, HP45
and
the
triosephosphate/
phosphate translocator
(TPT)
which
exchanges
triosephosphates from the stroma with anorganic phosphate
from the cytosol. Recent data on these analyses will be
presented.
P17: 23
Quantification and Visualisation of organellar DNA in
the diatom Phaeodactylum tricornutum
Materna A., Gruber A., Vugrinec S. and Kroth P.
[email protected]
Mitochondria and plastids evolved by endosymbiotic
processes. The endosymbionts were subsequently reduced
to organelles. Recent mitochondria and plastids contain
genomes which are derived from their ancestral prokaryotic
genomes, meaning that plants and most algae possess three
genomes per cell that have to be maintained, replicated and
inherited individually. We labeled plastid nucleoids in vivo
in the diatom Phaeodactylum tricornutum by fusing the full
length RecA protein to GFP. P. tricornutum plastids
possess either one big or several small nucleoids. The
number and distribution of nucleoids might be connected to
segregation of the plastid genome preceeding plastid
division. To assess the copy numbers of the organellar
genomes, we determined the exact copy number ratios of
plastid- mitochondrial- and nuclear genomes by
quantitative real-time PCR. Per nuclear genome copy,
approx. 69 copies of the plastid genome and approx. 310
copies of the mitochondrial genome are present in P.
tricornutum. Together with the known sequence length of
the respective genomes, it is possible to calculate a
theoretical DNA content per cell, which is consistent with
DNA contents determined in other studies on this
organism. The copy numbers determined in this study also
imply that more than half of the cellular DNA is contained
in the plastids and mitochondria. The two presented new
techniques allow to study the subcellular localisation of
nucleoids inside organelles, as well as their genome
contents.
P17: 24
Regulatory networks for chloroplast gene expression in
Chlamydomonas
Nickelsen J., Elles I. and Schwarz C.
LMU München, Germany; [email protected]
Gene expression in chloroplasts is mainly controlled at the
posttrancriptional level. In the green alga Chlamydomonas
reinhardtii, synthesis of the D2 protein (PsbD), which is
the rate-determining subunit for assembly of photosystem
II, depends on the RNA stability factor Nac2. In addition,
the RNA-binding protein RBP40 has been implicated in
translational control via a U-rich element in the 5´
POSTER ABSTRACTS
47
P17
untranslated region (5ÚTR) of the psbD mRNA. Here, we
report the identification of the RBP40 gene based on mass
spectrometric analysis of its purified product. We show that
RBP40 binds to the psbD 5ÚTR in a Nac2-dependent
fashion both in vitro and in vivo. Molecular
characterization of RBP40 RNAi lines confirmed that
RBP40 specifically affects the initiation of D2 synthesis.
Native PAGE, co-immunoprecipitation and sedimentation
analyses revealed that Nac2 and RBP40 form part of a
complex of 550 kDa that is displaced from the psbD
mRNA prior to polysome assembly. Taken together, the
data indicate that the processes of 5ÚTR-mediated RNA
stabilization and translation initiation are tightly coupled in
C. reinhardtii.
P17: 25
Similarities of the transcriptional systems in
chloroplasts and mitochondria
Bohne A.1, Kühn K.2, Ruf S.3, Liere K.1, Weihe A.1,
Bock R.3 and Börner T.1
1
Institute of Biology/Genetics, Humboldt-University,
10115 Berlin, Germany; 2Plant Energy, University of
Western Australia, Perth 6009 WA, Australia; 3Max Planck
Institute for Molecular Plant Physiology, 14476 Golm,
The transcriptional machineries of plastids and
mitochondria in higher plants exhibit striking similarities.
All mitochondrial genes and part of plastid genes are
transcribed by related phage-type RNA polymerases.
Furthermore, the majority of mitochondrial promoters and a
subset of plastid promoters show a similar structural
organization.
We have established an in vitro transcription system to
examine the abilities of the three Arabidopsis phage-type
RNAPs (RpoTm, RpoTp, and RpoTmp) to synthesize RNA
and to recognize organellar promoters. All three RpoT
genes were shown to encode transcriptionally active
RNAPs. RpoTmp displayed no significant promoter
specificity, whereas RpoTm and RpoTp were able to
accurately initiate transcription from overlapping subsets of
mitochondrial and plastidial promoters.
Furthermore we show that the mitochondrial atpA promoter
is recognized by plastid RNA polymerases in vitro and in
vivo. The RNA polymerase AtRpoTp, an enzyme localized
exclusively to plastids, was found to recognize the
mitochondrial atpA promoter in in vitro assays suggesting
the possibility that mitochondrial promoters might function
as well in plastids. We have, therefore, generated
transplastomic tobacco plants harboring in their chloroplast
genome the atpA promoter fused to the coding region of the
bacterial nptII gene. The chimeric nptII gene was found to
be efficiently transcribed in chloroplasts. Mapping of the 5’
ends of the nptII transcripts revealed correct recognition of
the atpA promoter by the chloroplast transcription
machinery.
P17: 26
Stepwise degradation of a xenobiotic glutathione
conjugate in the vacuoles of barley
Schröder P., Huber C. and Andres S.
GSF Forschungszentrum Neuherberg, Germany;
[email protected]
Plants as sessile organisms have to rely on a potent
detoxification system for organic xenobiotics and
pesticides. Numerous phase I and phase II enzymes and
genes have been identified in crops and weeds, and
48
POSTER ABSTRACTS
detoxification via the glutathione (GSH) dependent
pathway has been well established. The term storage
excretion has been coined for phase III, the transfer and
accumulation of glutathione conjugates (GS-X) in the
vacuole. This concept, reaching back to the initial
observations of xenobiotic metabolism, assumes the lack of
excretion systems in plants. However, tissue culture studies
point to rapid turnover of glutathione conjugates, resulting
in the transient accumulation of the related cysteine
conjugates.
In barley, the degradation of GS-X is clearly initiated by
vacuolar peptidases. These enzymes have been reported to
occur in relative abundance and are responsible for the
nonspecific C-terminal cleavage of oligopeptides. In
contrast, in Arabidopsis and tomato, the catabolism of GSH
and the cleavage of GS-X has been shown to be initiated by
g-Glutamyl-transpeptidase, catalyzing the transfer of Nterminal Glu from dipeptides and tripeptides – amongst
them also GSH and GS-X, to water or other acceptor amino
acids, hence leading to a new amide bond with N-terminal
g-linked Glu. We demonstrate that barley possesses both
pathways for the degradation of GS-X and that the resulting
product is even further metabolized.
Possible differences between barley and dicot experimental
systems are critically discussed.
P17: 27
Stress-induced alterations in the patterns of soluble
chloroplast proteins from leaves and callus of sugar beet
Reschke S., Lehnhardt L., Pufe H., Baumann I., Haebel
S. and Baumann G.
Universität Potsdam, Germany; [email protected]
Green callus must be cultivated at low light intensities to
avoid photodestruction. We looked for alterations in the
composition of soluble chloroplast proteins as indicators of
stress (light: 100 klx; heat: 45 °C). Soluble proteins were
separated by 2D-PAGE into up to 160 spots; significant
quantitative differences were detectable for about 5 % of
the spots. We could not find general stress indicators but
specific alterations for special stress conditions. Upon 1
and 2 hrs illumination of isolated callus chloroplasts the
most striking effect was a 2-6 fold increase of proteins
with [kDa; pI] (35; 4.9), (22; 5.0), (14; 4.1), (13; 4.1).
These proteins remained unchanged in light-stressed intact
callus, but here 8 other proteins are elevated (1.7 - 2.4fold). On the other hand, the (13; 4.1)-spot will also
increase when leaves or isolated chloroplasts from leaves
are illuminated or when callus is exposed to heat stress. A
(19.5; 5.1)-protein will continously decrease when callus or
leaves are exposed to heat stress for 1-3 hrs. This decrease
is most pronounced in callus (after 3 hrs 9 % of the control;
leaves: 59 %). This protein is unaffected by strong light.
According to MALDI-TOF analysis a protein of (72.5; 4.4)
is tentatively designated as Hsp 70. In the control the
amount of this spot was 1.3 % in leaves, but 3.2 % in
callus. After heat treatment there is an increase up to 2.8 %
in leaves, while the high content in callus remains
unchanged. One of the spots which are reduced at high
temperatures was identified as RUBISCO activase.
P17
P17: 28
Stress-inducible and constitutive phosphoinositide pools
have distinctive fatty acid patterns in Arabidopsis
thaliana
König S., Mosblech A. and Heilmann I.
[email protected]
Function and development of eukaryotic cells require tight
control of physiological processes. Numerous cellular
processes are regulated by phosphoinositides (PIs) which
interact with proteins or mediate release of second
messengers. Emerging evidence suggests that different
regulatory or signaling functions of PIs may be orchestrated
by the establishment of distinct subcellular pools; the
principles underlying pool-formation are, however, not
understood. Arabidopsis plants exhibit transient increases
in phosphorylated PIs with hyperosmotic stress, providing
a model for comparing constitutive and stress-inducible PI
pools. Using a combination of thin-layer-chromatography
and gas-chromatography, phospholipids from stressed and
non-stressed Arabidopsis were analyzed for their associated
fatty acids. Under non-stress conditions structural
phospholipids and phosphatidylinositol contained 50-70
mol% polyunsaturated fatty acids (PUFA), whereas
phosphorylated PIs were more saturated (10-20 mol%
PUFA). With hyperosmotic stress phosphorylated PIs with
up to 70 mol% PUFA were formed that differed from
constitutive species and coincided with a transient loss in
unsaturated phosphatidylinositol. The patterns indicate
inducible turnover of an unsaturated phosphatidylinositol
pool, which accumulates under standard conditions and is
primed for phosphorylation upon stimulation. Metabolic
analysis of wild type and transgenic plants disturbed in PI
metabolism suggests that, in contrast to saturated species,
unsaturated phosphorylated PIs are channeled towards
second messenger-production.
P17: 29
SynOxa1p is essential for co-translational integration of
D1 into thylakoid membrane
Sikorski M.1, Piekenhayn S.1, Schünemann D.2 and
Ossenbühl F.1
1
Universität Ulm, Molekulare Botanik, Germany; 2RuhrUniversität-Bochum, Germany; [email protected]
The membrane embedded PSII reaction centre protein D1
is known for its rapid decay in the light. The damaged
proteins have to be replaced by newly synthesized D1. A
member of the Alb3/YidC/Oxa1 protein family, the
membrane integral protein SynOxa1p in Synechocystis sp.
PCC6803, is involved in the integration, folding and
assembly of D1. To characterize the mode of interaction
between D1 and SynOxa1p, we initiated experiments with
the yeast split-ubiquitin system. In these assays we found a
direct interaction between SynOxa1p and the full length
D1. In further experiments we identified the interacting
region(s) in the N-terminal part of D1 within the first
transmembrane domain and the first luminal loop. To
investigate the time of the initial contact between
SynOxa1p and D1, we assayed the nascent D1 in isolated
polysomes from Synechocystis for interaction with
SynOxa1p. SynOxa1p is present in the polysomal fraction
by western blot analysis. In CoIPs of radiolabeled
polysomes with D1- and SynOxa1p-specific antibodies,
respectively, we detected bands with a molecular weight
that corresponds to translation intermediates of D1. The
presence of SynOxa1p in both CoIPs was clearly visible in
a western blot with a SynOxa1p-specific antibody which
suggests an early interaction of SynOxa1p with nascent
chains of D1. We conclude that D1 integration into PSII
and the thylakoid membranes occurs co-translationally with
SynOxa1p as an essential chaperone.
P17: 30
Targeting of plasma and vacuolar membrane localized
members of the TPK channel family
Dunkel M., Latz A., Becker D. and Hedrich R.
University of Würzburg, Germany; [email protected]
The vacuole represents a pivotal plant organelle for
management of ion homeostasis, storage of proteins and
solutes, as well as deposition of cytotoxic compounds. Ion
channels, pumps, and carriers in the vacuolar membrane
provide for ionic and metabolic homeostasis between this
storage organelle and the cytoplasm. TPK1, 2, 3, and 5,
members of the tandem-pore potassium channel family of
Arabidopsis thaliana, may contribute to the cellular
potassium homeostasis as they reside in the vacuolar
membrane. Another member of this family, TPK4, is a
plasma membrane K+-channel, instead (Becker et al.,
2004). Based on chimera between TPK1 and TPK4 we
searched for channel domains involved in the trafficking
process. Using fluorescent protein tags and confocal laser
scanning microscopy we discovered that TPK1 cytoplasmic
C-terminus is critically involved in ER as well as Golgi
sorting steps. Following site-directed mutagenesis we could
identify a diacidic motif (DXE) within the core CT
necessary for ER-export. TPK3 and TPK4 use other
trafficking mechanisms as they do not contain a diacidic
signal like TPK1. In contrast to animal counterparts 14-3-3
binding site of TPK1 was found essential for channel
activation but not sorting to the vacuole.
Becker, D., et al. (2004) AtTPK4, an Arabidopsis tandempore K+ channel, poised to control the pollen membrane
voltage in a pH- and Ca2+-dependent manner. PNAS 101,
15621-15626
P17: 31
Tat transport and spontaneous insertion of nuclear
encoded thylakoid proteins
Hanner P. and Schinke A.
Pflanzenphysiologie, Martin-Luther-Universität HalleWittenberg, Germany; [email protected]
Most thylakoid proteins are nuclear encoded and
synthesized in the cytosol as precursor proteins with transit
peptides mediating transport across the chloroplast
envelope. Subsequent transport into the thylakoid system
follows one of four distinct transport pathways operating at
the thylakoid membrane.
Two of these four pathways are of particular interest
because
of
their
unusual
mechanism.
The “spontaneous” membrane insertion pathway, which is
apparently the major aspect for bitope thylakoid proteins
like CFoII operates independently from NTPs, stromal
factors, membrane potential or even a proteinaceous
translocase
within
the
thylakoid
membrane.
The Tat (twin arginine translocation) pathway likewise
operates independently of NTPs or stromal factors, but
needs a translocase within the thylakoid membrane
consisting of the three subunits TatA, TatB and TatC.
Remarkably, transport by this pathway is still initiated by
the direct insertion of the Tat substrate into the lipid
POSTER ABSTRACTS
49
P17
bilayer. The most remarkable feature of the transport by the
Tat pathway is its property to translocate folded proteins.
How this is facilitated is analysed by using EGFP model
subtrates, which we use after refolding and purification for
in vitro experiments to compare the competition behavior
of folded and unfolded substrates. To investigate the
spontaneous insertion of proteins into the thylakoid
membrane, we use in vitro insertion experiments of
modified proteins in artificial membrane systems like
liposomes.
P17: 32
The basal apparatus subproteome of Chlamydomonas
reinhardtii
Brachhold K. and Melkonian M.
Universität Köln/Botanisches Institut, Germany;
[email protected]
The basal apparatus of the unicellular green alga
Chlamydomonas reinhardtii consists of the two flagellabearing basal bodies, two probasal bodies and fibres and
microtubules associated with the former. As the basal
bodies constitute the ultrastructural and functional
equivalent of the centrioles found in animal centrosomes
these organelles have been subjected to studies considering
their function and protein composition.Highly purified
preparations of basal apparatus were subjected to mass
spectrometry using MudPIT (multidimensional protein
identification technology) and gel-based methods with ESIMS/MS analyses. A core set of 35 putative novel basal
body proteins in addition to known basal body proteins was
identified. To further analyze several of the new proteins
partial cDNAs were cloned. A comparison of these cDNAs
with the respective gene models of the Chlamydomonas
database revealed major differences showing that many of
the models have not been assembled correctly. The cDNAs
were expressed in E. coli and the recombinant proteins used
to generate polyclonal antibodies in rabbits. The antibodies
were used to verify localization of the antigens to the basal
apparatus. The identification of a core set of basal
body/centriolar proteins now allows functional analysis
using an RNAi approach.
P17: 33
The crucial role of metabolite transporters in the
establishment of chloroplasts by endosymbiosis
Linka M.1, Tyra H.2, Bhattacharya D.2 and Weber A.1
1
Institute for Plant Biochemistry, Heinrich-HeineUniversity Duesseldorf; 2Roy J. Carver Center for
Comparative Genomics, University of Iowa;
[email protected]
The three major lineages of photosynthetic eukaryotes - red
algae, green algae/land plants, and glaucophytes originated through a single primary endosymbiosis between
a non-photosynthetic primitive eukaryote and a
cyanobacterium. Gene transfer from the cyanobacterial
genome to the nucleus and the establishment of a
retargeting system for the nuclear encoded proteins,
resulted in a massive genome reduction and eliminated the
symbiont’s autonomy. However, these steps do not
satisfactorily answer the question what the initial benefit
was in the early formation of the endosymbiosis. We
hypothesize that the insertion of host solute transporters
into the cyanobacterial plasma membrane was an early and
critical step in forming a permanent symbiosis by
establishing a metabolic link between host and
endosymbiont. To understand the role and evolution of the
50
POSTER ABSTRACTS
plastid transporter repertoire we initiated a comparative
analysis of membrane proteins from distantly related
photosynthetic organisms using ~130 annotated plastid
inner
envelope
membrane
transporters
from
Arabidopsis thaliana as a query. The host profits in
particular by the export of sugar-phosphates derived from
cyanobacterial carbon fixation. The corresponding protein
is absent in prokaryotes, but highly conserved in
photosynthetic eukaryotes. Phylogenetic analysis supports a
single origin from an existing endomembrane hosttranslocator. To verify the conserved transport activity in
all three major lineages we analyzed the transport
specificity of the homologous proteins from the ancient red
alga Galdieria sulphuraria.
P17: 34
The DYW subgroup of PPR proteins: Correlation to
RNA editing in plant organelles?
Rüdinger M., Polsakiewicz M. and Knoop V.
Universität Bonn, IZMB, AG Molekulare Evolution,
The genes of the recently recognized RNA binding
pentatricopeptide repeat (PPR) proteins form one of the
largest gene families in angiosperms with about 450
members in Arabidopsis. Genetic and functional data
support their involvement in organellar RNA processing
events including the still enigmatic process of RNA editing
(pyrimidine exchanges) in mitochondrial and chloroplast
transcripts. In our studies we investigate the phylogenetic
distribution of PPR protein genes with specific conserved
carboxyterminal extensions (E, E+ and DYW domains) in
land plants. We focussed on their distribution within
liverworts, the basal clade of land plants, given that RNA
editing seems to be conspicuously absent in the subclass of
complex thalloid (marchantiid) liverworts. We have
identified PPR protein genes on genomic and transcript
levels in jungermanniid liverworts and also in
Haplomitrium, a genus with an extremely high rate of RNA
editing sites, which is placed basal-most in the liverwort
phylogeny. However, we were unable to identify these
genes in a wide sampling of complex thalloid
Marchantiidae, perfectly congruent with the occurrence of
RNA editing in the first land plants. This correlation
suggests that members of the DYW subgroup of PPR
proteins indeed play at least an important role in
recognition of specific RNA editing sites in organelle
RNAs.
P17: 35
The mitochondrial ABC-type transporter ATM3
represents a crosspoint between Mo- and ironhomeostasis
Teschner J.1, Lachmann N.1, Selbach K.1, Balk J.2,
Mendel R.1 and Bittner F.1
1
Department of Plant Biology, TU Braunschweig,
Germany; 2Department of Plant Sciences, University of
Cambridge, UK; [email protected]
In all eukaryotic molybdenum (Mo)-containing enzymes
Mo is complexed by a pterin, thus forming the
molybdenum cofactor (Moco) which represents the
catalytic site of these enzymes. The first step of Moco
synthesis is the conversion from GTP to cPMP catalysed by
the iron-sulfur cluster ([Fe-S])-dependent Cnx2. In the next
step, cPMP is converted into molybdopterin (MPT) before
active Moco is generated. In total extracts of the A. thaliana
atm3-ko mutant sta1, which is deficient in the
P17
mitochondrial ABC-transporter ATM3 that exports [Fe-S]
from mitochondria into the cytosol, the amounts of MPT
and Moco are strongly reduced whereas cPMP accumulates
up to 6-fold. In purified mitochondria both, wildtype and
mutants, accumulate cPMP. While wildtype mitochondria
show a 2-fold accumulation, mitochondria of sta1 mutants
represent a more than 15-fold accumulation, indicating that
the [Fe-S]-dependent formation of cPMP is localized in
mitochondria and that obviously the export of cPMP into
the cytosol is affected by the sta1-mutation. Interestingly,
the activities of the cytosolic Mo-enzymes aldehyde
oxidase (AO), a key enzyme of ABA-biosynthesis, and
xanthine dehydrogenase (XDH), involved in purine
degradation, are nearly abolished. In contrast, the activity
of nitrate reductase (NR) is reduced only by 50%. This is
explained by the fact that in addition to Moco, AO and
XDH also require [Fe-S], whereas NR does not. As both,
the supply of cytosolic [Fe-S] and the synthesis of Moco
depend on mitochondria, the ATM3 transporter represents a
crosspoint between Mo- and iron-homeostasis.
P17: 36
The RNA editing efficiency of several sites differs
between ecotypes in Arabidopsis thaliana
mitochondriaZehrmann A., van der Merwe J.,
Verbitskiy D., Brennicke A. and Takenaka M.
University Ulm, Molecular botany, Germany;
[email protected]
RNA editing in flowering plant mitochondria changes more
than 400 nucleotide identities from C to U. Most of these
sites are conserved between different plant species, but
quite a few are species specific and present in one plant and
not the other. We have initiated a survey of the variation of
RNA editing sites between different ecotypes of
Arabidopsis thaliana. When comparing 400 editing sites
between the ecotypes Columbia, Landsberg erecta and
C24, we find seven sites which are edited in 100 % of the
mRNA population of one ecotype, but are altered in only
about 50 % of the transcripts of another ecotype. Three of
these ecotype-specific partial editings events are in silent
codon positions, while four are involved in changing the
encoded amino acid identity. Furthermore we find a
number of editing sites which differ in the plant lines
analysed here from the results reported for the tissue
culture line of Arabidopsis thaliana ecotype C24. Twelve
novel sites are identified in the leaves of young plants and
conversely 50 sites are not detected. This degree of
variation between plants and tissue cultures as well as
between different ecotypes shows that RNA editing sites
are very dynamic and can change rapidly particularly in
their penetration of the steady state mRNA population.
P17: 37
Transcription and RNA processing in plant
mitochondria are independent processes
Hinrichsen I., Bolle N. and Kempken F.
Universität Kiel, Bot.Institut, Ohlshausenstr.40, 24098
transcribed regions like introns. The mechanism of RNA
editing in plant mitochondria is still largely unknown.
To analyse splicing and editing we used an established
system which consists of electroporation of plant
mitochondria and in organello incubation. RT-PCR and
sequencing were used to evaluate editing and splicing.
In previous analyses we have shown that the cox2 gene of
maize and Arabidopsis thaliana introduced into
heterologous mitochondria was transcribed, and the
transcripts were efficiently spliced and edited. We were
now interested in the association of transcription and the
processing machinery in plant mitochondria. We
introduced an in vitro transcript of the Arabidopsis thaliana
cox2 gene into mitochondria of maize and cauliflower. The
introduced in vitro transcript was correctly spliced and
edited in organello at all editing sites analysed. Our
observations show that the process of editing and splicing
is not directly connected to transcription in plant
mitochondria.
Currently several other constructs are evaluated for their
processing in organello to analyse the connection of
transcription, splicing and editing.
P17: 38
Transcription of chloroplast genes: phage-type RNA
polymerases in Arabidopsis and their promoters
Swiatecka-Hagenbruch M., Hedtke B., Liere K. and
Börner T.
Humboldt-Universität zu Berlin, Institut für
Biologie/Genetik, Germany; [email protected]
Plastids evolved from a cyanobacterial ancestor and have
retained their own genome and a gene expression system.
Nevertheless they require nuclear gene products for
biogenesis and function. Accordingly, transcription of
plastid genes in higher plants is due to a bacterial-type
multi-subunit RNA polymerase (PEP) recognizing
sigma70-type promoters with -10 and -35 regions and a
nuclear-encoded phage-type RNA polymerase (NEP)
transcribing from promoters with different architecture. In
Arabidopsis, a small nuclear gene family encodes
chloroplast as well as mitochondrial phage-type RNA
polymerases: RpoTp and RpoTm, which are targeted to
plastids and mitochondria and RpoTmp, which is found in
both organelles (Hedtke et al., 2000).
To investigate the individual roles of RpoTp and RpoTmp
in transcription of plastid genes we have analyzed the
utilization of NEP and PEP promoters in Arabidopsis plants
with introduced copies of the RpoT cDNAs under control
of the CaMV promoter. Multiple RpoTp overexpression
was found to correlate with a decreased transcription of the
rpoB gene from the NEP promoter class I and of the psbA
gene from the PEP promoter, whereas the transcription of
the clpP gene from the NEP promoter class II was not
negatively affected.
To learn about promoter specificities in plastid
transcription Arabidopsis albino plants with ribosomedeficient plastids were generated (Zubko & Day, 1998).
These plants were used for mapping of transcription
initiation sites of selected plastid genes.
Mitochondrial transcripts of plants are processed by
different mechanism like intron splicing and RNA editing.
Editing is a post-transcriptional process in higher plant
mitochondria which is characterised by C-to-U and
sometimes U-to-C conversions at specific sites. There exist
up to 500 editing sites in plant mitochondria and nearly all
transcripts of peptide coding genes are affected by editing.
In addition there are also editing sites in non-coding
POSTER ABSTRACTS
51
P17/P18
P17: 39
tRNase Z proteins in Arabidopsis thaliana
Canino G. and Marchfelder A.
Universität Ulm, Germany; [email protected]
Transfer RNAs (tRNA) play an important role in protein
translation delivering the amino acids to the ribosome.
tRNAs are synthesised as precursor molecules containing
5´ and 3´ extensions and sometimes also introns. In
Eukaryotes and Archaea the 5´ processing event is
catalyzed by the well-characterised enzyme RNase P. Much
less is known about the RNase P counterpart for 3´
processing, tRNase Z. tRNase Z proteins exist in two
forms: a short one (280-360 amino acids long) which is
found in Archaea, Bacteria and Eukaryotes, and a long one
which is found only in Eukaryotes (750-930 amino acids
long). In Eukaryotes, tRNase Z catalyzes the
endonucleolytic removal of pre-tRNA 3´ extension,
generating a tRNA ready for CCA addition. Arabidopsis
thaliana has 4 different tRNase Z genes, the highest
number found in one organism up to now. In silico and in
vivo analysis suggest a different cellular localisation of
these proteins. In vitro analysis shows that these proteins
can actively process pre-tRNAs. While the knock out
mutant for AthZ2 is not viable, the single knock out of the
other homologous proteins does not show any evident
phenotype. The lack of a phenotype in the absence of one
tRNase Z can be explained by a compensative role of the
remaining proteins. The generation of tRNase Z double
knock outs and detailed molecular analysis of them are
planned to understand the biological functions of these
enzymes in A. thaliana.
P18: PHOTOSYNTHESIS
AND ASSIMILATION
P18: 1
Pectate Lyases, Plasmodesmata and Phloem Unloading
in Arabidopsis thaliana
Gerlitz N., Werner D. and Stadler R.
Friedrich-Alexander-University of Erlangen-Nürnberg,
Plasmodesmata form symplastic connections between plant
cells. Development, structure and regulation of
plasmodesmata are poorly understood. We investigated
phloem unloading into developing seeds of Arabidopsis.
We showed that functional plasmodesmata develop at the
phloem ending in developing seeds right after flower
opening. In developing seeds, phloem mobile fluorescent
tracers are unloaded symplastically only after flower
opening. To monitor plasmodesmata directly, we used a
transgenic plasmodesmata marker line (35Sp:MP17-GFP).
In the phloem unloading area in seeds we detected
plasmodesmata only in open flowers, not in buds. To
investigate the role of cell wall modifying enzymes during
this developmental stage we addressed the function of
putative pectate lyases in plasmodesmata formation.
Pectate lyases catalyze degradation of pectin which is an
early step in cell wall degradation. We analyzed four genes
coding for putative pectate lyases, which were predicted to
be expressed in developing seeds. Reporter gene analyses
detected promoter activity in the phloem unloading area of
developing seeds. T-DNA-insertion mutants were crossed
52
POSTER ABSTRACTS
with AtSUC2p:GFP plants to introduce the GREEN
FLUORESCENT PROTEIN as a phloem mobile tracer,
which is synthesized in companion cells and traffics in the
phloem sap towards sink tissues. Three of the four mutants
showed a similar phenotype: short pods with a decreased
number of seeds per pod and delayed phloem unloading of
GFP. Our results suggest a distinct function of pectate
lyases during plasmodesmata formation
P18: 2
14-3-3 proteins meet glycolysis
Jaspert N.1, Weckermann K.1, Piotrowski M.2 and
Oecking C.1
1
ZMBP Plant Physiology, Germany; 2Lehrstuhl für
Pflanzenphysiologie, Ruhr-Universität Bochum, Germany;
[email protected]
Members of the eukaryotic 14-3-3 protein family have been
implicated in the regulation of distinct biological processes
by protein-protein interactions. Most notably, 14-3-3
proteins bind to pS/pT motifs in a sequence specific
manner. While several hundred 14-3-3 interacting partners
are known in animals, the knowledge about plant target
proteins is marginal. We therefore established a proteomic
approach to identify novel plant target proteins. This led to
the identification of 14-3-3 target proteins involved in
stress responses and metabolism, among those the
glycolytic enzyme enolase. Recent findings have shown
that the Arabidopsis enolase LOS2 is bifunctional in that it
additionally functions as a transcription factor required for
the expression of cold responsive genes (Lee et al., 2002).
Accordingly, a GFP fusion of LOS2 is localized in the
cytoplasm as well as the nucleus. Interestingly, “BiFC”analysis indicates that the interaction between 14-3-3 and
LOS2 is restricted to the cytoplasm, suggesting that 14-3-3
binding sequesters LOS2 in this compartment. With the
aim of analysing the in vivo relevance of this interaction, a
los2 knock-out was identified, which shows a severe
dwarfish phenotype. This is intriguing taking into account
that Arabidopsis expresses 2 additional enolases one of
which shows a subcellular localization comparable to
LOS2. Complementation of the phenotype will be analysed
by expression of the wild-type versus a non 14-3-3
interacting mutant variant of LOS2.
P18: 3
A Stereo Imaging System for Measuring Structural
Parameters of Plant Canopies
Biskup B., Scharr H., Schurr U. and Rascher U.
Forschungszentrum Jülich GmbH, Germany; [email protected]
Plants constantly adapt their leaf orientation to maintain
radiation use efficiency under varying intensity and
incidence direction of sunlight. Various methods exist for
measuring structural canopy parameters such as leaf angle
distribution. Direct methods tend to be labour-intensive,
however, while indirect methods usually give statistical
information on the level of stands rather than of individual
leaves. Here, we present a binocular stereo system that
allows 3D reconstruction of small to medium sized
canopies on the level of single leaves under field
conditions. Leaf orientation is computed with automated
processes using modern, well-established stereo matching
and segmentation techniques adapted for the properties of
plant canopies, providing high spatial and temporal
resolution. We demonstrate the applicability of our
approach in three case studies: (1) The dihedral leaflet
P18
angle of an individual soybean leaf was tracked to monitor
leaf movement; (2) Drought stress was diagnosed in
soybean by quantifying changes in the zenith leaflet angle
distribution; (3) The diurnal course of the zenith leaf angle
distribution of a closed soybean canopy was measured.
Elevated CO2 (Soybean free air concentration enrichment
facility; SoyFACE) showed no effect on canopy structure,
indicating that increased biomass gain under elevated CO2
is due to upregulation of leaf photosynthesis. Our system
has useful applications, e.g. in studying the impact of
canopy structure on light penetration and on photosynthetic
efficiency.
P18: 4
Making the connections - the role of intracellular
metabolite transport in photosynthesis and
photorespiration
Weber A.1, Linka M.1,2, Gagneul D.1, Bräutigam A.1,2
and Linka N.1
1
Heinrich-Heine-Universität Düsseldorf, Germany;
2
Graduate Program in Genetics, Michigan State University,
East Lansing, USA; [email protected]
Eukaryotic cells are most fascinating because of their high
degree of compartmentation. This is particularly true for
plant cells, due to the presence of chloroplasts,
photosynthetic organelles of endosymbiotic origin that can
be traced back to a single cyanobacterial ancestor. The
photosynthetic organelle (plastid) in red, green, and
glaucophyte algae (Plantae) likely had a single origin from
a cyanobacterial endosymbiosis. This ancient (ca. 1 to 1.5
billion years ago) event was followed by the transfer of
genetic material from the endosymbiont to the nuclear
genome of the host, the evolution of a plastidic protein
import apparatus, and of targeting sequences directing
nucleus-encoded proteins to the plastid. Plastids are major
hubs in the metabolic network of plant cells, their
metabolism being heavily intertwined with that of the
cytosol and of other organelles. Solute transport across the
plastid envelope by metabolite transporters is key to
integrating plastid metabolism with that of other cellular
compartments.
Using genomics, proteomics, and bioinformatics analysis of
transcriptomics datasets, we have identified several novel
solute transporters in chloroplasts, peroxisomes, and
mitochondria that are involved in intracellular trafficking of
photosynthetic and photorespiratory intermediates and end
products. We will present functional data obtained with
recombinant, reconstituted transporter proteins and we will
show detailed physiological analyses of transgenic plants
lacking particular transporter functions.
P18: 5
Adaptation of photosynthetic electron transport (PET)
to CAM metabolism in Mesembryanthemum
crystallinum and its impact on plastid gene
transcription
Niewiadomska E.1, Bilger W.2, Miszalski Z.1,3 and
Krupinska K.2
1
Institute of Plant Physiology Polish Academy of Sciences,
Krakow, Poland; 2Institute of Botany Kiel University, Kiel,
Germany; 3Institute of Botany Pedagogical Academy,
Krakow, Poland; [email protected]
In the halophytic plant M. crystallinum, a shift from C3 to
CAM metabolism occurs as a response to drought or
salinity treatment. This was accompanied by a decrease in
maximal PSII efficiency (Fv/Fm) after the induction of
CAM, most pronounced at the end of the dark period. Thus,
suggesting that CAM performance may affect the
efficiency of PSII in the dark phase, whilst, PET can be
adjusted during the light period. We hypothesize that either
the efficiency of PSI increases or that alternative electron
sinks are activated in CAM. To verify this hypothesis, PSI
efficiency was analyzed. CAM plants at the end of the day
had a significantly increased maximal and effective PSI
efficiency in comparison to C3 plants. These data indicate
that in CAM plants the balance between PSII and PSI may
change during the day, a result of which is an increased
capacity of PSI or PSI-associated electron sinks at the end
of the light period. In order to investigate whether this
adjustment of PET be regulated at the level of plastid
transcription, run-on transcripts were hybridized to DNA
probes representing several photosynthesis related genes. In
CAM-induced plants the relative transcription rate of
photosystem II associated genes (psbA, psbD) was higher
in comparison to those of photosystem I associated genes
(psaA/B operon). The indication of more oxidized
plastoquinone pool in CAM was given by the the faster
decay of PSII-derived fluorescence. We hypothesize that a
dramatic change in the redox state of PQ pool have an
important regulatory function in adaptation to CAM
metabolism.
P18: 6
Anatomical investigations on stomata: Preliminary
studies for the reconstruction of atmospheric carbon
dioxide.
Grein M.
University of Tuebingen, Germany; [email protected]
Stomata have attracted considerable interest as a CO2 proxy
for past climates especially within the context of the current
anthropogenically induced rise of atmospheric carbon
dioxide. It has often been observed that plants change the
stomatal density of their leaves inversely with atmospheric
CO2 in order to optimize photosynthesis by maximizing
assimilation and minimizing transpiration through open
stomata. Knowledge of palaeoatmospheric CO2 and its
change is crucial for exploring the coupling of global
climate change and atmospheric CO2.
A mechanistic approach was developed (see contribution of
W. Konrad and A. Roth-Nebelsick) in order to analyze the
variation of stomatal density induced by CO2 change. The
model works on the evolutionary time scale. The approach
consists of three submodels coupling 1) the process of
diffusion through both the epidermis and the plant tissue, 2)
the biochemical process of photosynthesis and 3) an
optimisation principle relating carbon gain and water loss.
The model is tested by using anatomical, biochemical and
ecophysiological data of extant plants. In this contribution,
preliminary results of various extant species are presented.
P18: 7
Biological functions of isoprene: Some plants like it hot,
some don’t
Schnitzler J.
Forschungszentrum Karlsruhe IMK-IFU, Germany; [email protected]
The physiological role of isoprene emission in plants is a
matter of debate. One of the most propagated hypotheses is
the protection of leaf metabolic processes against thermal
and oxidative stress. The underlying physiological
POSTER ABSTRACTS
53
P18
mechanisms are largely unknown. To test function(s) of
isoprene, we constructed Grey poplar lines, in which gene
expression of isoprene synthase (ISPS) was knocked down
and Arabidopsis constitutively over-expressing ISPS. Gas
exchange studies applying transient heat cycles (up to
40°C) showed distinct differences in thermal sensitivity
between both species:Non-isoprene-emitting poplars were
reduced in net assimilation and ETR during heat cycles but
not in the absence of stress. The decrease in photochemical
efficiency was inversely correlated with the increase in heat
dissipation of absorbed light energy measured as NPQ. In
Arabidopsis, transient temperature stress had no negative
effect on net assimilation of WT and isoprene-emitting
plants, indicating that Arabidopsis doesn’t need isoprene as
a protection against thermal stress. However, isopreneemitting rosettes showed transiently enhanced growth rates
under moderate thermal stress. In summary it becomes
clear that in poplar isoprene emission positively influenced
photosynthetic electron transport and energy dissipation
keeping net assimilation stable under transient thermal
stress. In Arabidopsis, even if isoprene emission is not
involved in transient protection of net assimilation,
isoprene formation may retain growth or coordinated
vegetative development under a moderate temperature
increase.
P18: 8
CHANGES IN PHOTOSYNTHESIS, GROWTH AND
YIELD OF GRAPEVINES GROWN IN ELEVATED
CO2: A 3-YEAR FIELD STUDY
Correia C., Moreira C., Bacelar E., Gonçalves B.,
Martins R., Ferreira H., Cunha J., Falco V. and Pereira
J.
University of Trás-os-Montes e Alto Douro, Portugal;
[email protected]
Grapevines of a common Portuguese cultivar, Touriga
Franca, were grown in open-top chambers at the ambient
and at an elevated (500 mmol mol-1) CO2 concentration.
Higher CO2 increased total yield, ranging from 27% in
2005 to 50% in 2004 and 2006, and pruning weight, mainly
in 2005 (58%). Must and wine quality were not
significantly affected by elevated CO2. Grape sugar
concentration at ripening was stimulated by rising CO2
levels, only in 2005, while there were no differences in
titrable acidity, tartaric and malic acid concentrations.
Moreover, with the exception of isoamyl acetate that
decreased under elevated CO2, no effects of CO2 were
detected in the other important aroma compounds of wines.
Gas exchange measurements indicated that elevated CO2
enhanced net photosynthetic rate and decreased stomatal
conductance, leading to greater intrinsic water use
efficiency. The A/Ci curves demonstrated that maximum
carboxylation rate of Rubisco (Vcmax) and light-saturated
rate of electron transport (Jmax) were similar, suggesting
that there was no downward acclimation of photosynthetic
capacity in elevated CO2. Analysis of leaf metabolites
showed that starch content was higher under enhanced
CO2, whereas soluble sugars and phenolic compounds
concentration were raised by CO2 in 2004 and 2006,
respectively. Furthermore, no effects of CO2 were observed
on photosynthetic pigments and soluble proteins content.
Thus, in the absence of environmental stresses, grapevines
would perform well under rising atmospheric CO2
concentration as predicted for this century.
54
POSTER ABSTRACTS
P18: 9
Changes in the regulation of photosynthesis for nitrogen
fixation during acclimation to different irradiances in
Trichodesmium
Seibert S.1 and Küpper H.1,2
1
Budejovice, Czech Republic; [email protected]
We explored interactions between photosynthesis and
nitrogen-fixation under different irradiance conditions in
the
filamentous,
non-heterocystous,
diazotrophic
cyanobacterium Trichodesmium IMS101. In general, in
Trichodesmium nitrogen fixation and photosynthesis occur
at the same time in the same cells. Single-cell spatially and
spectrally resolved fluorescence kinetic measurements of
single cells revealed that changes in photosynthetic activity
during the diel activity cycle and during acclimation to high
irradiance (HL) were related to differential (un)coupling of
phycobilisomes to/from photosystems, changing the
effective cross-section of PS II. Further, HL increased the
number and prolonged the time period of the occurrence of
“bright II” cells with uncoupled phycobilisomes, which
seemed to be related to apoptotic cell death and to the
fragmentation of Trichodesmium filaments. These cells
show a more than three times higher dark adapted basic
chlorophyll fluorescence F0 over a certain time. In low
irradiance, bright II cells and fluorescence quenching cells
did not occur; only the non-diazotrophic “normal F0” cells
and the bright I cells related to nitrogen fixation were
observed. Further, HL acclimation involved a decrease of
Chl and light-harvesting carotenoids and an increase in βcarotene like carotenoids involved in light protection.
Phycobilisome content per cell, in contrast, remained
constant, confirming that their contribution to light
harvesting is regulated by reversible coupling instead of
changes in expression level.
P18: 10
Characterization of the oligomeric antenna of the
diatom P. tricornutum
Lepetit B.1, Volke D.2, Szabó M.3, Hoffmann R.2, Garab
G.3, Wilhelm C.1 and Goss R.1
1
Institute of Biology I, Plant Physiology, University of
Leipzig; 2Institute for Bioanalytical Chemistry, University
of Leipzig; 3Institute of Plant Biology, Biological Research
Center, Szeged; [email protected]
The photosynthetic antenna system of diatoms contains
fucoxanthin chlorophyll a/c binding proteins (FCPs), which
exhibit high homology to the LHCs of vascular plants.
Recent reports have indicated that the FCPs exist in an
oligomeric state. To gain further information about FCP
oligomerization we performed a detailed study of the
antenna organization of the diatom P. tricornutum.
Solubilization of thylakoids with different concentrations of
the detergent n-dodecyl β-D-maltoside (DM) in
combination with sucrose density centrifugation and
gelfiltration yielded two FCP complexes with different
oligomerization states. At low detergent concentrations we
found an oligomeric complex which was termed FCPo, at
higher DM concentrations an FCP complex with a lower
oligomerization state was observed. Calculation of the
molecular mass of these two complexes by gelfiltration
showed that the FCP complex is trimeric, whereas the
FCPo consists of either hexamers or two associated trimers.
Spectroscopic characterization of both FCP complexes
P18
revealed that the FCPo most likely represents the native
state of the peripheral antenna. The identity of the FCP
proteins was confirmed by MS/MS, which further allowed
the assignation of the FCPs to their respective genes. Our
data also show that the peripheral antenna contains the
main part of the xanthophyll cycle pigments diadinoxanthin
and diatoxanthin, but that a small pool is additionally
bound to the photosystem core fractions. This indicates the
existence of a xanthophyll binding protein tightly
associated with the photosystems.
P18: 11
Characterization of the putative iron sulfur protein
IdiC (ORF5) in Synechococcus elongatus PCC 7942
Michel K., Pietsch D. and Pistorius E.
Universität Bielefeld, Fakultät für Biologie, Molekulare
Zellphysiologie, G; [email protected]
The gene idiC is part of the iron-responsive idiB operon of
S. elongatus PCC 7942 and encodes a protein with a
putative transmembrane helix. IdiC belongs to the
thioredoxin-like ferredoxin family. IdiC has similarity to
NuoE of the E. coli NDH-1 complex. IdiC expression
increase under iron starvation and also in the late growth
phase, representing growth conditions, which favor
photosynthetic cyclic and respiratory electron transport
over photosynthetic linear electron transport from water to
NADP+. Insertional inactivation of idiC generated
merodiploid mutants. Thus, IdiC seems to be an essential
protein for the viability of S. elongatus under the used
experimental conditions. Comparative analyses WT and
mutant showed that MuD had a lower growth rate,
chlorophyll content, and photosynthetic O2 evolving
activity with bicarbonate as electron acceptor than WT.
Immunoblot analyses also showed that in MuD, when
grown under iron limitation, the amount of the proteins
IdiC and IdiB was greatly reduced as compared to WT. As
a consequence of the reduction of the transcription factor
IdiB, IdiA and IrpA expression were also decreased. In
addition, the IsiA protein concentration was lower in MuD
than in WT, although the isiA mRNA was equally high in
MuD and WT. Another major difference was the lower
expression of the ferredoxin:NADP+ oxidoreductase in
mutant MuD under iron limitation compared to WT. A
possible function of the protein IdiC in cyclic electron
transport around photosystem I and/or in respiratory
electron transport will be discussed.
P18: 12
Characterization of TSP9 RNAi lines
Krech K., Kleine T. and Strand Å.
Umeå Plant Science Centre, Department of Plant
Physiology; [email protected]
TSP9 (thylakoid soluble protein, 9 kDA) is a plant
specific, nuclear encoded protein which is imported into the
chloroplast but with still unknown function . TSP9 was
found to be released from the spinach thylakoid membrane
upon light treatment in. Together with recent localization
studies which showed that TSP9 is most abundant in grana
stacks and interacting strongly with LHCII, it was
suggested that it is involved in determining the LHCII
affinity towards the photosystems and possibly playing a
role in state transition.
We investigated three independent Arabidopsis TSP9
RNAi-lines, where the repression of TSP9 transcript varies
between 40 and 80% compared to wild type. The knock
down level was confirmed also at the protein level using
Western blotting with a TSP9 specific antibody.
Furthermore, the transgenic lines were characterized after
treatment with three different light intensities, 100 (LL),
500 (ML) and 1,000 µmol m-2 s-1 (HL). Interestingly, the
transgenic lines differ in anthocyanin content following
exposure to ML and HL compared to the wild type but not
in chlorophyll content. No differences in maximum
quantum yield for PSII (Fv/Fm) could be shown for ML but
in HL the TSP9 RNAi lines clearly demonstrate a light
sensitive phenotype. The chlorophyll fluorescence data are
not different in the RNAi lines compared to the wild type
upon increasing light intensities. These data indicate, that it
is unlikely that TSP9 has an important role in state
transition. More likely, TSP9 is involved in plastid-tonucleus communication.
P18: 13
DNA microarray analysis of an IdiC-mutant of
Synechococcus elongatus
Nodop A.
Universität Bielefeld, Abteilung für Molekulare
Zellphysiologie, Germany; [email protected]
We applied the DNA microarray technology to the
unicellular cyanobacterium Synechococcus elongatus PCC
7942 being a model organism for oxygenic photosynthesis.
An interesting topic in S. elongatus research is the
adaptation to limiting nutrients, e.g. Fe. Besides
optimization of Fe acquisition systems, S. elongatus
specifically modifies its electron transport chain under Fe
limitation by enhanced expression of two proteins, IdiA
and IsiA. IdiA protects the acceptor side of photosystem
(PS) II, while IsiA has been assigned multiple functions
including the formation of a membrane-integral lightharvesting antenna around trimeric PS I complexes. In this
talk I will report on a comparative DNA microarray
analysis between S. elongatus WT and an IdiC
Synechococcus mutant grown under Fe-sufficient or Fedeficient conditions. The IdiC protein is encoded by orf5
being part of the Fe-responsive idiB operon. IdiB is the
transcriptional regulator of IdiA expression The IdiC
protein belongs to the thioredoxin-like [2Fe-2S] ferredoxin
family. Moreover, IdiC has similarity to NuoE of the E.
coli NDH-1 complex. IdiC expression increases under Felimitation and also in the late growth phase. These growth
conditions favor photosynthetic cyclic and respiratory
electron transport over photosynthetic linear electron
transport from water to NADP+. Attempts to insertionally
inactivate the idiC gene generated merodiploid mutants
with a strongly reduced IdiC content but no IdiC-free
mutant. Thus, IdiC seems to be an essential protein for the
viability of S. elongatus under experimental conditions.
P18: 14
Effect of sink manipulation on C assimilation and C
allocation of barley plants (Hordeum vulgare L.) during
generative phase
Beschow H., Egle K. and Merbach W.
Martin-Luther-University Halle-Wittenberg, Institute of
Agricultural and Nutritional Sciences, Professorship Plant
Nutrition, Germany; [email protected]
To study the mechanism of substance transport within
barley plants the ear was manipulated during 5 days before
feeding the flag leaf with 14CO2. The manipulation of the
sink strength of the ear included ear darkening, application
of cytokinin onto the ear and partial removal of the ear.The
flag leaf was fed with 14CO2 over 2 h in special leaf
POSTER ABSTRACTS
55
P18
cuvettes. 24 h later the plants were harvested and divided
into ear, flag leaf, internodes above and under flag leaf and
other leaves. The 14C radioactivity was measured in these
plant parts. The suppression of ear photosynthesis by ear
darkening enhanced the transport of 14C from the flag leaf
into the ear. But ear removal decreased this transport.
Cytokinin spraying onto the ear has increased slightly but
not significantly the transport of 14C from the flag leaf into
the ear.According to the differences in the transport of 14C
ear darkening and cytokinin spraying onto the ear increased
the 14C radioactivity in the ear by 100% while removal of
half or 2/3 of the ear reduced it drastically by 80% in
comparison to the control plant without manipulation.
Simultaneously chlorophyll contents in the flag leaf was
significantly higher in plants treated with cytokinin as
compared to control plants: 2.96 and 1.69 mg g-1 fresh
weight respectively. Apparently cytokinin avoided the
degradation of chlorophyll in leaves and might delay the
photosynthesis activity for sustaining C source during grain
filling.
P18: 15
Expression of a plastidic G6PD isoform in the cytosol
accelerates defence responses in tobacco
Scharte J.1, Schön H.1, Mezher Z.2, Weis E.1 and von
Schaewen A.2
1
Plant Physiology, Institute for Botany, WWU Münster,
Germany; 2Molecular Physiology, Institute for Botany,
WWU Münster, Germany; [email protected]
Following pathogen attack, ROS production in the apoplast
(oxidative burst) contributes to direct killing of pathogens
and cell-wall fortification, finally leading to cell death. In
plant cells, NADPH oxidases (driven by carbohydrate
consuming, NADPH generating reactions in the cytosol,
like the G6PD reaction) are considered to be the main
source for apoplastic ROS generation. Since recuperation
from imbalances in intracellular redox states largely relies
on NADPH provision, stress responses are intimately
linked to the nutritional state of a cell.
To test the effects of elevated NADPH availability upon
pathogen-challenge, we generated transgenic tobacco plants
that express a modified plastidic G6PD isoform from
Arabidopsis (P2 class, Ki > Km [NADPH]) in the cytosol. In
the susceptible Nicotiana tabacum cultivar Xanthi,
transgenic cP2 lines with highest cytosolic P2 mRNA and
protein levels developed hypersensitive lesions reminiscent
of the resistant cultivar Samsun NN after infiltration of
Phytophthora nicotianae zoospores. Also, the oxidative
burst and defence-induced changes in photosynthetic and
metabolic parameters (source/sink transition) are
comparable to the resistant cultivar.
Interference of Glucosamin-6-P (G6PD inhibitor) and DPI
(NADPH oxidase inhibitor) with ROS production and
formation of hypersensitive lesions indicated that after
elicitation, NADPH oxidase at the plasma membrane
benefits from elevated NADPH availability in the cytosol,
allowing oxidative burst and downstream signalling and
finally leading to hypersensitive cell death and efficient
plant defence.
P18: 16
Glucan, water dikinase (GWD) activity enhances
breakdown of leaf starch by chloroplastic ß-amylases
Edner C. and Ritte G.
Institute of Biochemistry and Biology, University of
Potsdam, Germany; [email protected]
56
POSTER ABSTRACTS
Transitory starch is accumulated in chloroplasts throughout
the day and is degraded in the subsequent night. Starch
granules contain phosphate bound to the C6- or C3-position
of glucosyl residues. Starch phosphorylation is catalyzed by
the enzymes glucan, water dikinase (GWD) and
phosphoglucan, water dikinase (PWD). Arabidopsis
mutants lacking GWD or PWD are impaired in proper
starch breakdown and exhibit significantly increased leaf
starch contents with the phenotype of the GWD-deficient
plants being more severe.
To explore the link between phosphorylation and
breakdown of starch we searched for starch degrading
enzymes from Arabidopsis whose activities are affected by
glucan phosphorylation. Candidate proteins were enriched
from leaf extracts by consecutive chromatographic steps
and identified using MS. Among other known starchrelated proteins, the debranching enzyme isoamylase 3
(ISA3) and ß-amylase 1 (BAM1) were detected, which are
both localized in plastids.
Experiments using purified recombinant enzymes showed
that BAM1 activity increased about twofold if the starch
granules were simultaneously phosphorylated by
recombinant potato GWD. This effect was also observed
with BAM3, another chloroplastic BAM isoform. Mixing
BAM and isoamylase significantly enhanced granule
degradation, which was further increased in the presence of
GWD and ATP. ß-amylolytic attack on the granules in turn
considerably stimulated the GWD-catalyzed starch
phosphorylation. The interdependent activities of GWD
and BAM offer an explanation for the starch excess
phenotype of GWD-deficient plants.
P18: 17
Hybrid complexes from biological and synthetic
materials for light-harvesting and charge separation
applications
Gundlach K.1, Grundmann G.2, Wolfgang E.2, Peneva
K.3, Müllen K.3, Basché T.2 and Paulsen H.1
1
Institut für Allgemeine Botanik, Mainz, Germany; 2Institut
für Physikalische Chemie, Mainz, Germany; 3Max Planck
Institut für Polymerforschung, Mainz, Germany;
[email protected]
Light harvesting chlorophyll a/b complex (LHCIIb) is a
major component of the photosynthetic apparatus in higher
plants. It non-covalently binds 8 chlorophyll a, 6
chlorophyll b and 4 carotinoids. These pigments serve to
harvest light energy and to transfer it to the photosynthetic
reaction centers. LHCIIb exhibits an astonishing ability to
assemble in vitro from the denatured, bacterially expressed
apoprotein and plant pigments.
We want to utilize the light-harvesting function of LHCIIb
in organic/inorganic/biological hyprid complexes. To this
end, we bind it to organic rylene dyes and inorganic
semiconductor nanocrystals. Our aim is to analyse and
optimise both the chemical and optical coupling between
these components.
P18: 18
Identification and Kinetic Properties of Glycerate
Kinase from Rice, Yeast and Nostoc
Bartsch O., Hagemann M. and Bauwe H.
University of Rostock, Institute of Biological Sciences;
[email protected]
The recently identified glycerate kinase (GLYK) of the
model plant Arabidopsis thaliana catalyzes the final
reaction of photorespiratory C2 cycle. Phylogenetic
P18
analyses revealed that the Arabidopsis GLYK is prototypic
for a new class of plant glycerate kinases which also
comprises homologs from fungi and cyanobacteria. We
have now analysed kinetic properties of putative GLYKs
from the plant Oryza sativa, the yeast Saccharomyces
cerevisiae, and the cyanobacterium Nostoc sp. PCC 7120.
These proteins and Arabidopsis GLYK were overexpressed
in E. coli and purified using a fused His-tag. All four
purified proteins showed strong glycerate 3-kinase activity
and did not accept any other substrate for phosphorylation
than D-glycerate. Kinetic properties of recombinant
Arabidopsis GLYK were similar to the native protein. The
same was found for the recombinant GLYK from rice.
Yeast and Nostoc GLYK showed an about 2-fold higher
affinity to glycerate compared to the plant GLYKs. Affinity
towards ATP, the second GLYK substrate, was much
higher for Nostoc GLYK in comparison with the other
three examined enzymes. The structural reason for these
differences and their metabolic meanings remain to be
investigated. Summarizing, these data confirm that the
putative GLYKs from plants, fungi and cyanobacteria are
indeed D-glycerate 3-kinases. While the plant and possibly
cyanobacterial GLYKs are involved in the photorespiratory
C2 cycle, it is not clear in which metabolic pathway the
fungal GLYK participates.
St (Hesse, Germany; Naumann et al. 2007) showed an
almost tenfold higher EC50 value of 3.0 µM. Carotenoids
were inhibited at very similar effective concentrations as
chlorophyll (0.6 µM and 3.4 µM, respectively). Toward
Hg2+ these two clones are also the most sensitive and most
tolerant wild strains, respectively, out of 25 from all over
the world according to the biomonitoring test (ISO 20079).
In almost all clones (23 out of 25) growth parameters on
the basis of fresh weight were the most sensitive indicating
the regulation of the water content as an important target of
Hg2+ toxicity.
Ref.: Naumann B, Eberius M, Appenroth K-J (2007)
Growth rate based dose-response relationships and ECvalues of ten heavy metals using the duckweed growth
inhibition test (ISO 20079) with Lemna minor St. J Plant
Physiol, in press
P18: 19
The role of photosynthesis during plant defence is
discussed controversially. On the one hand, light energy
could be used to create ROS and, thereby, facilitate the
hypersensitive reaction (HR). On the other hand, the
photosynthetic metabolism is assumed to compete with
carbohydrate-consuming pathways involved in defence
and, thus, could even impede defence. Such competing
reactions are, e.g., NADPH-generating cytosolic glucose-6phosphate dehydrogenase (cG6PDH), which is thought to
support ROS generation by the plasmalemma NADPHoxidase.
We demonstrate, that 1-6 hours after infection of leaves of
resistant tobacco (Nicotiana tabacum cv. SNN) with
Phytophthora nicotianae, CO2-uptake, the photosynthetic
electron transport and the export of photoassimilates
collapse, before respiration, cG6PDH-activity and ROSgeneration strongly increase and cell death occurs. Our
current studies reveal that the appearance of hypersensitive
lesions is clearly delayed in the light, compared to leaves
infected in the dark.
These observations suggest that defence is impeded by the
photosynthetic metabolism and, therefore, a breakdown of
photosynthesis is a prerequisite for the onset of defencesupporting metabolic reactions, such as cG6PDH-activity.
Also, the obstruction of photosynthesis in plants infected in
the light could contribute to the formation of intracellular
ROS, which, in turn, initiates light-driven HR. The timecourse and pattern of ROS production is notably altered in
plants infected in the dark. Therefore it is likely that
different pathways initiate the HR in the light or in the
dark.
Identification of a cytosolic hydroxypyruvate reductase
acting in the photorespiratory cycle
Timm S. and Bauwe H.
Universität Rostock, Germany; [email protected]
The conversion of 3-hydroxypyruvate (3HP) to D-glycerate
is an important step in the photorespiratory glycolate cycle.
It is generally assumed that this reaction is catalyzed
exclusively by the peroxisomal enzyme NADH:3HP
reductase (HPR1). On the other hand, involvement of an
extraperoxisomal NADPH-dependent 3HP reductase was
also suggested (Kleczkowski et al. 1988). We have purified
this alternative 3HP-reducing enzyme, HPR2, from HPR1deficient Arabidopsis mutants and identified the encoding
gene by mass spectrometric protein sequencing. In order to
verify its biochemical function, the ORF was overexpressed in E. coli. The recombinant enzyme shows high
HPR activity in the presence of NADPH, but lower activity
with NADH. Similar to HPR1-deficient plants, HPR2
knockout mutants grow normally in photorespiratory
conditions. The relative contributions of HPR1 and HPR2
to photorespiratory metabolism will be discussed.
P18: 20
Influence of mercury on the photosynthetic apparatus
depends on the clonal sensitivity in Lemna minor L.
Appenroth K. and Thomas S.
University of Jena, Institute of Plant Physiology, Germany;
[email protected]
Application of Hg2+ to the duckweed Lemna minor resulted
in decreased levels of photosynthetic pigments both in adult
plants and in fronds developing during the seven-days test.
In stronger light the toxic effects were stronger than in
weaker light. Therefore, formation of reactive oxygen
species seems to play a dominating role as molecular
mechanism of the toxicity of Hg2+. Toxicity depends on the
specific clone of Lemna minor. Clone L02 (Thuringia,
Germany) showed a 50 % inhibition (EC50) of the
chlorophyll content at 0.4 µM, whereas the standard clone
P18: 21
Light and photosynthesis - Antagonists or facilitators of
the resistance of tobacco leaves against Phytophthora
nicotianae?
Schön H., Scharte J., Schmitz-Thom I., Essmann J. and
Weis E.
Institut für Botanik, WWU-Münster, Germany;
[email protected]
P18: 22
Light screening of anthocyanins in leaves of Berberis
thunbergii
Nichelmann L. and Bilger W.
Botanical Institute, CAU Kiel, Germany;
[email protected]
Plants have to cope with the antagonism of light harvesting
to drive their metabolism on one side and of protecting
themselves against excessive light energy, which has the
POSTER ABSTRACTS
57
P18
potential to damage photosensitive structures, on the other
side. Anthocyanins may attenuate light in leaves because of
their absorbance and their specific localisation in the
epidermis or upper palisade parenchyma. If anthocyanins
shield photosynthetically active radiation (PAR) an
acclimatisation of the photosynthetic apparatus to a
permanent decrease of photon flux density should take
place. To test this hypothesis, plants of Berberis thunbergii
and Berberis thunbergii atropurpurea with anthocyanic
leaves were grown under identical light conditions in a low
light (30 µmol m-2 s-1), in a medium light (130 µmol m-2 s1
) and in a high light (500 µmol m-2 s-1) environment in
climate chambers. The screening of PAR by anthocyanins
was quantified by chlorophyll fluorescence measurements
and correlated well with light limited oxygen evolution.
Shade acclimation of the photosynthetic apparatus was
assessed by photosynthetic pigment contents (chl a/b ratio
and xanthophyll cycle pool size) and the ultrastructure of
the chloroplasts. The data show that a considerable fraction
of PAR is screened from the photosynthetic apparatus,
resulting in shade acclimation.
P18: 23
Light Stress Proteins in the diatom Phaeodactylum
tricornutum
Ng Chin Yue S., Vugrinec S., Kroth P. and Lavaud J.
Universität Konstanz, Germany; [email protected]
Diatoms are important photoautotrophic eukaryotes widely
distributed in all marine and freshwater ecosystems. Light
fluctuations in their underwater environment can be very
high. To maintain an optimal photosynthesis in a
permanently changing light regime, diatoms have evolved a
number of regulatory mechanisms. The photoprotective
NPQ (non-photochemical chlorophyll fluorescence
quenching) process allows the cells to safely dissipate the
energy absorbed in excess during light stress. Xanthophyll
pigments and specific light-harvesting complex (LHC)
polypeptides are necessary for the NPQ mechanism. In
cyanobacteria hlips (high light induced protein), which are
members of the elip (early light induced protein) family
were found to play a role in the high light acclimation of
the cells.
Five members of the elip family were found in
Phaeodactylum tricornutum: 1 elip, 3 hlips and 1 sep
(stress enhanced protein). We studied the gene expression
of all five genes under different light intensities and at
different illumination times. First results show that the elips
are indeed overexpressed under high light. This suggests
that they might play a role in the light stress acclimation of
the diatoms.
P18: 24
Molecular aspects of proton/electron and metabolite
supply for chloroplast hydrogenase activity in green
algae
Beckmann J., Doebbe A. and Kruse O.
Universität Bielefeld, AG Algenbiotechnologie, Germany;
[email protected]
Oxygenic photosynthetic organisms use solar energy to
split water (H2O) into protons (H+), electrons (e-), and
oxygen. A select group of photosynthetic microorganisms,
including the green algae Chlamydomonas reinhardtii, has
evolved the additional ability to redirect the derived H+ and
e- to drive hydrogen (H2) production via the chloroplast
hydrogenases HydA1 and HydA2 (H2ase). This process
58
POSTER ABSTRACTS
occurs under anaerobic conditions and provides a
biological basis for solar-driven H2 production.
The aim of this project is to define key molecular
mechanisms controlling photon, proton (H+) and electron
(e-) flow during photosynthetic H2 production in the green
algae C. reinhardtii. The program consists of further
modules and builds on the high H2 producing mutant (~ 2%
photon conversion efficiency). Two of the goals are the
identification of key targets of metabolic fluxes for solar to
hydrogen conversion by GC-mass spectrometry and the
characterisation of protein levels by quantification with
LC-MS/MS. An additional strategy is to improve biomass
production with unicellular micro algae and to combine
solar-driven biomass and Bio-H2 production with the
technical development of an economically profitable algal
photo-bioreactor. This Solar Bio-H2 research program will
incorporate improvements with the aim of achieving solar
energy to H2 conversion efficiencies of up to 10 %.
P18: 25
Physiological effects of long-term response (LTR) to
light quality gradients in Arabidopsis thaliana
Dietzel L., Wagner R., Bräutigam K. and Pfannschmidt
T.
FSU Jena, Germany; [email protected]
Acclimation to different light quality gradients is of great
importance especially in dense plant populations. Using a
light system favouring excitation of PSI or PSII,
respectively, we mimick such light gradients. As long-term
response (LTR) an adjustment of photosynthetic
stoichiometry occurs that has been suggested to adjust the
photosynthetic
apparatus
and
consequently
its
photosynthetical performance to the prevailing conditions.
This process involves perception of the light stimulus
probably by the thylakoid kinase STN7, a signal
transduction cascade and adjustment of plastid as well as
nuclear gene expression.
The LTR process is known for several years, but the benefit
for plant survival and reproduction has never been shown
before. To attain insights in physiological processes
occurring during LTR, we documented plant morphology,
determined chlorophyll fluorescence parameter, chloroplast
ultrastructure and thylakoid membrane phosphorylation.
The real benefit of the LTR on the level of reproduction
and plant survival was estimated by comparing WT and the
stn7 mutant (which is defective in LTR) under long-term as
well as under short-term shifts.
Acclimated plants showed better photosynthetic
performance than non acclimated plants. Furthermore, nonacclimated plants exhibited higher steady state NPQ than
plants acclimated to the light sources.
Our investigations demonstrated for the first time the real
beneficial effect of the LTR for plant survival and
reproduction.
P18: 27
RNAi MEDIATED REPRESSION OF CELL WALL
INVERTASE IMPAIRES DEFENCE REACTIONS IN
TOBACCO
Essmann J., Schön H., Schmitz-Thom I., Weis E. and
Scharte J.
Institut für Botanik, Westfälische Wilhelms-Universität
Münster, Germany; [email protected]
Cell wall invertase (cwINV), the key enzyme of the
apoplastic phloem unloading pathway, generates metabolic
signals known to effect various processes of primary
P18
metabolism and defence. The induction of cwINV by
various stresses indicates a coordinated regulation of plant
source/sink relations and the response to pathogens.
Defence reactions require metabolites, energy and reducing
equivalents. In photoautotrophic cells sugar-consuming
pathways are tuned down in favour of photosynthesis.
Photosynthates are rapidly exported. Thus, source cells are
not well suited for defence and require a strategy to retain
soluble carbohydrates.
To elucidate the role of cwINV as a precondition and/or
concomitant of a successful defence, we generated tobacco
plants with constitutive repression of two cwINV isoforms
(SNN::RNAi cwINV). Compared to the resistant cultivar
SamsunNN, there is no remarkable change in the
phenotype of the transgenic plants, but source leaves
exhibit impaired defence reactions after infection with the
Phytophthora nicotianae: a rapid increase in cwINV
activity and the establishment of a high sugar state are
absent, callose deposition and oxidative burst are
alleviated. In addition, repression of cwInv seems to make
a resistant cultivar much more susceptible.
We postulate that the shift towards a non-assimilatory,
carbohydrate consuming “sink-type metabolism”, leading
to hypersensitive cell death, is at least an essential
integrated part of a successful plant defence and necessarily
requires the induction of cwINV activity.
P18: 28
Significance of molecular crowding in grana
membranes
Haferkamp S.1, Mullineaux C.2, van Amerongen H.3,
Haase W.4 and Kirchhoff H.1
1
Institute of Botany, WWU Muenster, Germany;
2
Department of Biological Science,Queen Mary University
London,Great Britain; 3Department of Biophysics,
Wageningen UR, The Netherlands; 4Structural Biology,
MPI of Biophysics, Frankfurt a.M., Germany; [email protected]
Grana membranes are crowded by photosystem (PS) II and
its antenna system (LHCII). The significance of this high
protein packing for the supramolecular arrangement of PSII
and LHCII as well as its effect on the light-harvesting
function and the stability of the PSII-supercomplex (PSIILHCII-dimer) is poorly understood. We developed a
procedure which enables a controlled dilution of the protein
density in isolated grana membranes (BBY) by fusion with
unilamellar liposomes consisting of native lipids. Density
gradient centrifugation, electron microscopy, lipid analysis
and fluorescence lifetime imaging microscopy visualise the
incorporation of lipids and the molecular protein
organisation. Spectroscopic analyses of the diluted
membranes indicate a stepwise breakdown of the extended
supramolecular network between PSII and LHCII.
Detachment of LHCIIs correlates almost linearly with the
lipid/chlorophyll ratio, indicating weak interaction between
LHCII and PSII. In contrast the quantum yield of PSII
photochemistry, the connectivity between PSIIα and the
PSIIα to β conversion are apparent only when the protein
density is lowered below a critical threshold. The interplay
between weak and strong protein interactions, becoming
manifest in there differential dependency on protein density
could reflect a compromise between the flexibility of the
protein arrangement and a high efficiency of light
utilization. Molecular crowding in grana membranes in
combination with weakly interacting antenna complexes
seems to ensure an effective energy transfer.
P18: 29
Spectrally & spatially resolved microscopic
measurements of Chl and non-Chl fluorescence kinetics
provide new insights into photosynthesis & abiotic
stress
Küpper H.1,2, Leitenmaier B.1, Parameswaran A.1,
Seibert S.1, Šetlík I.2,3 and Trtílek M.4
1
Budejovice, Czech Republic; 3Microbiological Institute,
ASCR, Třeboň, Czech Republic; 4Faculty of Biol Sciences
& Institute of Physical Biology, Brno, Czech Rep.;
[email protected]
We developed a novel fluorescence kinetic microscope that
allows for simultaneous spectrally and spatially resolved
fluorescence kinetic measurements.
Applied to the Cd/Zn hyperaccumulator Thlaspi
caerulescens, it revealed that in healthy plants, maximal
PSII efficiency (Fv/Fm) was homogeneous from 650790 nm, suggesting that in healthy T. caerulescens all Chls
fluorescing at room temperature are PSII-associated. Cd
toxicity reduced Fv/Fm and ΦPSII stronger at 670-740nm
compared to >740nm and <670nm, but enhanced
nonphotochemical quenching mainly <690nm. These
spectral distributions of Cd-effects show that Cd inhibits at
least two different targets in/around PSII. Differential
effects of Cd-stress on photochemical vs. nonphotochemical parameters further indicated that Cd inhibits
the photosynthetic light reactions more than the Calvin
cycle. Finally, spatial heterogeneity of photosynthesis and
metal accumulation was found in Cd-stressed leaves; it
disappeared upon acclimation.
Application of this technique to the non-heterocystous
diazotrophic cyanobacterium Trichodesmium revealed that
changes in photosynthetic activity were related to
differential (un)coupling of phycobilisomes to/from
photosystems, changing the effective cross-section of PSII
and photosystem connectivity. Further, we found that
phycobilisomes can be so closely coupled to PSII that their
fluorescence emission exhibits strong photochemical and
weak non-photochemical quenching, opening a new way
for studying energy transfer within phycobilisomes and
towards the PSII reaction centre.
P18: 31
The biomass production in acidic environment: A direct
comparison of C. acidophila growing at pH 2,65 and 6,5
Langner U.
University of Leipzig, Germany; [email protected]
Coal mining lakes can be very acidic reaching pH values
down to 2. However, even under such acidic conditions the
primary production can be relatively high leading to
significant chlorophyll concentrations in the lakes.
Chlamydomonas acidophila, isolated from an acidic lake,
was analysed at pH 2,65 and 6,5 to understand, how the
cells can grow efficiently under such low pH. For
comparison C. reinhardtii was grown under identical
conditions at pH 6,5. Chl a in vivo fluorometry was
combined with gas exchange measurements to quantify
photosynthetic efficiency. The biomass was quantified and
analysed with the help of FT-IR (Fourier transformation
infrared) spectroscopy to determine the macromolecular
composition of the biomass. With this setup it was possible
to quantify a complete balance from absorbed photons to
the unit carbon in biomass. The results show that in the
POSTER ABSTRACTS
59
P18/P19
acidic environment C. acidophila has a higher growth rate
compared to pH 6,5. This can be explained by the fact that
under acidic conditions the ratio of assimilated carbon per
harvested photon is increased and less energy is wasted for
alternative electron cycling and respiration. A comparison
between C. reinhardtii and C. acidophila reveals a second
new fact: the more the growth is limited the less reduced is
the newly formed biomass reflected by an increased
carbohydrate to protein ratio.
P18: 32
The impact of photosynthetic redox signals in
chloroplast-to-nucleus communication and metabolic
acclimation
Bräutigam K.1, Biehl A.2, Schauer N.3, Oliver S.3, Fernie
A.3, Geigenberger P.3, Leister D.4 and Pfannschmidt T.1
1
Institute of Plant Physiology, University of Jena,
Germany; 2Max Planck Institute for Plant Breeding
Research, Cologne; 3Max Planck Institute for Molecular
Plant Physiology, Golm; 4Faculty of Biology, Department
Biology I, LMU Munich; [email protected]
Photosynthetic signals generated upon environmental
changes can influence plastid as well as nuclear gene
expression, thus photosynthesis contributes to the
regulatory crosstalk between the nucleus und the
chloroplast of a plant cell. Here, we focus on redox signals
which originate from the photosynthetic electron transport
chain. To reproducably generate such redox signals under
non-stress conditions, A. thaliana plants were shifted
between light sources which preferentially excite either
photosystem I or photosystem II. Such changes in incident
light quality induce uneven excitation of the photosystems
and alter the redox state of the plastoquinone pool. These
redox changes in turn trigger short-term and long-term
acclimation responses like state transition or adjustment of
photosystem stochiometry. To investigate the impact of
such photosynthetic redox signals, RNA was isolated from
plants shifted between the photosystem-specific light
sources. Subsequent array analysis allowed to identify more
than 100 redox-regulated nuclear genes. In addition, the
velocity of chloroplast-to-nucleus signalling was examined.
The observed difference in the overall expression patterns
during acclimation to an oxidation and a reduction signal
might indicate different metabolic states of the plant cells.
This was confirmed by analyzing levels of various
metabolites in response to an oxidation and reduction
signal, respectively. Linking transcipt patterns with
metabolic levels suggests a close connection of redox
signalling and metabolic control.
P18: 33
The Sep3 and Sep4 proteins of Arabidopsis thaliana
associate with the light harvesting antenna
Lohscheider J., Andersson U., Huesgen P. and Adamska
I.
Universität Konstanz, Germany; [email protected]
The Stress-enhanced proteins (Seps) are part of the
Chlorophyll (Chl) a/b-binding super family (CAB) of
proteins in plants. In Arabidopsis thaliana, 5 members have
been identified so far. Seps are predicted to share specific
characteristics with the Lhc proteins of the photosystem I
(PSI) and photosystem II (PSII) antenna complexes,
including three-dimensional structure, a chloroplast
60
POSTER ABSTRACTS
targeting sequence, and Chl binding motifs. However, Seps
contain only two transmembrane helices and are therefore
expected to act as dimers in order to bind Chl.
Among the five SEP genes, Sep3 and Sep4 are very similar
with 67% identity on the nucleotide level and approx. 80%
identity on protein level. We managed to raise specific
antisera against both proteins. Using these antibodies, we
obtained preliminary data indicating an association of these
proteins with the Lhc antenna.
P19: PHYTOHORMONES –
METABOLISM AND
FUNCTION
P19: 1
In vitro germination and growth of petunia (Petunia
hybrida) male gametophyte: endogenous
phytohormonal level and effects of exogenous
phytohormones
Zakharova E., Minkina Y., Timofeeva G., Andreev I.
and Kovaleva L.
Institute of Plant Physiology, RAS, Russian Federation;
[email protected]
The participation of phytohormones (IAA, ABA, GA and
cytokinins) and flavonols (quercetin and kaempferol) in
regulation and growth of male gametophyte was shown. In
vitro germination and growth of petunia male gametophyte
were accompanied by an increase in hormone and flavonol
contents.Their greatest stimulatory effect was recorded at
10-12M. Pollen germination was stimulated mainly by GA3
and ABA, whereas the elongation of pollen tubes by GA3.
Fluridon, an inhibitor of ABA synthesis, and paclobutrazol,
an inhibitor of GA synthesis, lowered to a various degree
the rate of pollen germination and pollen tube growth,
whereas 2-(4-chlorophenoxy)-2-methylpropionic acid, an
inhibitor of IAA transport, inhibited them completely. For
the first time, phytohormones were shown to take part in
cytoplasmic pH (pHc) regulation in germinating male
gametophyte.
P19: 2
Analytical and biochemical studies on the melatonin
synthesis in Viola plants
Kim Y., Oh Y. and Park* W.
Bk21 Graduate Program for RNA Biology, Department of
(Republic of); [email protected]
More than 50 Viola species commonly distribute in Korea
and have been utilized in traditional medicine, e.g., Viola
mandshurica. However, active ingredients of curing effects
of the plant extracts are still unknown. Because Viola plants
are used for curing diverse symptoms of diseases, there
may be multiple components that reveal medicinal
activities. Among the probable many chemicals, we noticed
melatonin that was known to exist in high amount in Viola
mandshurica. Melatonin (N-acetyl-5-methoxytryptamine)
is a neurohormone that corrects circadian rhythm in
animals. It is primarily synthesized from tryptophan via
four steps of biochemical reactions mainly in the
mammalian pineal gland. Interestingly, the indoleamine
hormone has been discovered also from some higher plants,
P19
e.g., St. John's wort. However, the biosynthesis and
function of phyto-melatonin still remains largely unknown.
In study, we are analyzing melatonin in Viola plants by
applying HPLC and GC-MS, and investigating the possible
precursors, intermediates and the enzymes involved in
melatonin biosynthesis. Ultimately, the goal of this work is
to elucidate the role of melatonin in Viola plants and open
possibilities for practical application. [This work was
supported by the Korea Research Foundation Grant funded
y the Korean Government (MOEHRD) (KRF-2006-331C00258)]
in our department showed that six member out of the
predicted family are plastidic enzymes. Some of these
putative lipases show dramatic changes in their RNA level
after wounding or coronatine treatment, stimuli where
Jasmonate is the key signal. (M. Jünger 2006). Based on
this experiments we are interested in to study the function
of this proteins and their putative role in oxylipin
biosynthesis. Therefore we use a GST-fusion expression
system on one hand and Arabidopsis RNAi-mutant lines on
the other. Here we report the biochemical characterization
of a DAD1-like phospholipase encoded by the gene
At1g05800 and their mutant.
P19: 3
P19: 5
Auxin promotes the activities of aldehyde oxidases in
maize (Zea mays) roots.
Oh Y., Cho Y., Lee Y., Hwang I. and Park* W.
(Republic of); [email protected]
Aldehyde oxidase (EC 1.2.3.1) has been suggested to
catalyze the final step of Trp-dependent IAA (indole-3acetic acid) biosynthesis and ABA production. In
Arabidopsis, aldehyde oxidase has been investigated
mainly as the ABA synthesizing enzyme, and the function
of the enzyme in auxin biosynthesis still remain unclear. In
an effort to verify the function of aldehyde oxidases related
to the synthesis of IAA and ABA, we found the stimulatory
effect of auxin, when applied to the growing plants, on
aldehyde oxidase activities in assays based on the activity
staining of the enzyme, i.e., zymogram, with indole-3carboxyaldehyde as a substrate on a native native-PAGE
gel. The effects of exogenously applied auxins do not seem
to be stress-responses following chemical treatment,
because inactive auxin homologue 2-NAA did now
stimulate aldehyde oxidase activities at physiological
concentrations. The increased activities were explained by
increased transcription and translation aldehyde oxidase
genes. We are currently measuring the level of IAA and
ABA in the samples treated with auxin to observe the
relationship between the increased enzyme activities and
the two hormone levels by HPLC and GC-MS.
P19: 4
Characterisation of a plastidic DAD1-like lipase
Ellinger D., Cin H., Schmidt S. and Kubigsteltig I.
Department of Plant Physiology, Ruhr-Universität
The oxylipin biosynthesis pathway starting with linolenic
acid and their corresponding enzymes are well known and
have been studied in detail. But until now it is unknown
where the starting substrates come from. A high amount of
lipids from chloroplast membranes contain linolenic acid or
other intermediates of the oxylipin biosynthesis pathway
(Stelmach et al. 2001). It seems obvious that there exist one
or more lipases releasing the fatty acids from the membrane
lipids in response to a stimuli leading to oxylipin
biosynthesis. The plastidic phospholipase DAD1 is such an
enzyme playing an important role in Jasmonate
biosynthesis during flowering processes (Ishiguro et al.
2001). The Arabidopsis thaliana mutant dad1 (defective in
anther dehiscence) shows defects in anther dehiscence,
pollen maturation and has reduced Jasmonate level in the
flower buds. Based on amino acid homologies further
DAD1-like proteins have been predicted. Previous studies
CHARACZERIZATION OF LOSS-OF-FUNCTION
MUTANTS OF CYTOKININ DEHYDROGENASE
GENES IN ARABIDOPSIS THALIANA
Bartrina I., Werner T. and Schmülling T.
Institute of Biology/Applied Genetics, Freie Universität
Berlin, Germany; [email protected]
The inactivation of cytokinins is catalyzed by cytokinin
oxidases/dehydrogenases (CKX). To assign functions to
each individual AtCKX gene of Arabidopsis, we isolated 13
homozygous insertional mutants of six of the seven genes.
Knockouts of single AtCKX genes showed minimal
consequences for plant development, indicating functional
redundancy. To overcome this problem, insertion lines
were systematically crossed to produce double and multiple
knockout mutants. Specific allel combination caused the
formation of larger and more active inflorescence
meristems, which led to an increased rate of flower
primordia initiation and flower production. The flowers
were bigger and had often an increased number of floral
organs, which indicated an enhanced activity of the floral
meristem. The gynoecia of these mutants were significantly
increased in size, contained more ovules and the developed
siliques were longer and produced more seeds. Our results
indicate that a sub-group of CKX genes probably acts as a
negative regulator of cell division activity during
developmental processes linked to generative growth.
P19: 6
Comparison of early, root-borne signals in maize
subjected to chilling or drought
Asch F.1 and Janowiak F.2
1
Universität Hohenheim, Stuttgart, Germany; 2Institute of
Plant Physiology, Polish Academy of Sciences, Krakow,
Pl; [email protected]
Plants often are subjected to root-borne stresses such as
drought or chilling influencing the plants’ water relations.
Stress symptom expression can be modified by air humidity
(rH). Roots convey stress via signal cascades to the leaves
inducing reductions in transpiration, comprising changes in
xylem [ABA], xylem pH and leaf water potential.
Depending on stress type, its timing and severity, plant
reactions to stress vary. Thus, composition pattern of signal
chains (SP) should also vary. We studied SP and plant
reactions to stress for the first 8h of partial root chilling
(PRC) and drying in 3 maize varieties in a split root system.
The lower root part (55%) was chilled at 8°C or exposed to
ambient air. In 30min intervals plants were sampled for
stomatal conductance (gs), chlorophyll fluorescence (CFl),
and xylem sap. The SP (xylem [ABA], xylem pH, water
potential) differed significantly between chilling and
drought, whereas the physiological reactions (gs, CFl) to
SP differed among the cultivars. We also studied the
POSTER ABSTRACTS
61
P19
influence of rH on SP induced by PRC, in the same set-up.
The additional stress of low rH modified SP and
physiological reactions only in the sensitive cultivar. Under
both rH, we observed transient ABA peaks and oscillating
xylem pH, but under low rH the ABA peak was 2.5 fold
higher and about 6h earlier, than under high rH. Xylem pH
oscillated (5.8 to 6.3) under high rH, independent of the
chilling treatment, but under low rH the chilling treatment
always had a pH of 0.5 units below control. Roles of SP in
regulating leaf physiological behavior are discussed.
P19: 7
Cross-talk of inositol-containing phospholipids and
oxylipin signaling during the wounding response of
Mosblech A., König S. and Heilmann I.
[email protected]
Various biochemical signals have been implicated in
wound signaling of Arabidopsis, including jasmonate (JA)
and Ca2+. Here we report on cross-talk of JA with
phosphoinositide (PI) signals not previously implicated in
plant wound-responses. Within 30 min of mechanical
wounding of Arabidopsis rosette leaves the levels of
inositol 1,4,5-trisphosphate (InsP3), increased from 2.9 ±
0.4 to 12.7 ± 3.0 nmol g-1 fresh weight. Concomitantly, the
levels of the lipid precursors also decreased transiently,
followed by resynthesis after 30-60 min of stimulation, as
evident by transiently increased PIP-kinase activity in vitro.
Raised InsP3 levels after wounding coincided with JA
increases over the first hours of stimulation. To address
cross-talk of JA and PIs, the dynamics of JA and InsP3
were monitored after wounding of wild type plants, dde2-2
mutant plants deficient in the synthesis of cyclic oxylipins
including JA, and of plants expressing a human type I
inositolpolyphosphate 5-phophatase, exhibiting reduced
InsP3 and PI levels. In dde2-2 plants no increase in InsP3
was observed upon wounding, indicating JA was required
for InsP3-formation. In InsP 5-ptase plants woundinginduced JA production terminated prematurely, suggesting
PIs are necessary for sustained JA formation. Monitoring of
transcript levels for wounding-inducible genes indicate that
PIs mediate JA-dependent induction of gene expression. In
addition to biochemical and gene expression data,
caterpillar feeding performance tests support an essential
and previously undescribed role for the PI-system in plant
defense.
P19: 8
Distribution and activity of cytokinins in Physcomitrella
Fernández Núñez M.1, Blaschke H.1, Novak O.2, Strnad
M.2, Motyka V.3 and von Schwartzenberg K.1
1
Biocentre Klein Flottbek, University Hamburg,
Ohnhorststr. 18, D-22609 Hamb; 2Laboratory of Growth
Regulators, Palacký University & Institute of Experime;
3
Institute of Experimental Botany, Academy of Sciences of
the Czech Republic; [email protected]
Cytokinins are well known plant growth regulators
involved in various developmental processes. We report on
cytokinin profiling of the bryophyte Physcomitrella. Using
UPLC-MS/MS we analysed 40 cytokinins in tissue and
culture
media.
Intracellular
Cis-zeatin-riboside-Oglucoside,
N6-(Δ2-isopentenyl)adenosine-5´monophosphate (iPRMP) and trans-zeatinriboside-Oglucoside were the most abundant cytokinins. In addition,
the aromatic- Cks N6-benzyladenosine (BAR), N6-
62
POSTER ABSTRACTS
benzyladenine (BA), meta- and ortho-topolin (mT, oT)
were detected. Unexpectedly, the most abundant
extracellular cytokinin was the nucleotide iPRMP. The
effects on the cytokinin distribution due to overexpression
of cytokinin oxidase/dehydrogenase (CKX) gene from
Arabidopsis (AtCKX2) were assessed. In cultures of CKXtransformed plants pronounced reductions in the
extracellular concentrations of N6-(Δ2-isopentenyl)adenine
(iP) and N6-(Δ2-isopentenyl)adenosine (iPR) were found,
although their intracellular cytokinin concentrations were
slightly affected. In vitro and in vivo measured CKX
activity was shown to be strongly increased in the
transformants. Major phenotypic changes observed in the
CKX-overexpressing plants included reduced and retarded
budding and abnormal protonema cells. In bud induction
bioassays with Physcomitrella wild type from 14 tested
cytokinins only iP, tZ, BA, BAR, iPR, tZR, mT, DHZ, oT
showed an effect. According to the results on wild type and
CKX transgenics we suggest that extracellular iP and iPR
are the main cytokinins responsible for bud induction in
Physcomitrella.
P19: 9
First Steps towards Development of Synthetic Promoter
to detect Jasmonic acid
Hossain M. and Hause B.
Leibniz Institute of Plant Biochemistry, Halle/Saale,
Creation of synthetic promoter with defined jasmonic acid
(JA) response elements will be useful to modulate plant
responses toward specific developmental, biotic and/or
abiotic cues as well as in cell- and tissue-specific detection
of JA. Allene oxide cyclase (AOC) plays an important role
in the biosynthesis of JA and its genes are highly
responsive to JA. Promoters of all four Arabidopsis
thaliana AOCs have been fused upstream of βglucuronidase (GUS) to analyze them in Arabidopsis
protoplasts. AtAOC1-4::GUS fusions conferred GUS
activity but failed to respond to JA. Additionally, two
synthetic promoters containing GCC-box and Jasmonate
and Elicitor Responsive Element (JERE) have been used
and caused high GUS activity but again no induction after
JA-treatment. These results revealed that protoplasts
isolated from Arabidopsis cell culture are not suitable to
study JA-induced gene expression transiently. Therefore,
promoter deletions generated from AtAOC3 promoter,
showing the highest GUS activity among the AtAOC
promoters, have to be used for stable transformation of
Arabidopsis. To test the effectiveness of deletions,
protoplasts have been transformed with eight different
deletions fused to GUS. It appeared that one JA-responsive
element might be present between deletion 6 and 7, and
another between deletion 7 and 8. To locate the position of
element(s) precisely, further deletions have been generated
and tested. Besides this, the respective promoter::GUS
fusions have been cloned into the binary vector pBINPLUS
for Agrobacterium-mediated stable transformation of
plants.
P19: 10
Functional and structural properties of Arabidopsis
amidase 1
Neu D., Lehmann T., Elleuche S. and Pollmann S.
Ruhr-Universität Bochum, Germany; [email protected]
Amidase 1 (AMI1) is a specific indole-3-acetamide (IAM)
hydrolase from Arabidopsis thaliana. The enzyme is
P19
capable of converting IAM into the plant hormone indole3-acetic acid (IAA). Thus it may contribute to the still not
completely elucidated de novo biosythesis of this major
auxin. AMI1 can be classified as a member of the so called
amidase signature family, an enzyme family sharing a
glycine and serine rich stretch of about 50-130 conserved
amino acids, the name-giving amidase signature. Members
of this family are found widespread in nature, catalyzing a
diverse range of enzymatic reactions. The crystal structure
of a fatty acid amide hydrolase from rat and of a bacterial
malonamidase revealed an unusual Ser-cisSer-Lys catalytic
triad, replacing the assumption of an Asp-Ser-Cys active
site. We addressed the question for catalytic relevant amino
acids in AMI1 by examining the influence of chosen single
amino acid mutations and chemical modification of active
site residues on substrate conversion of heterologously
expressed enzyme. Our data suggests a similar mechanism
for amide hydrolysis to the compared enzymes.
In contrast the influence of Ser137 on substrate conversion
is higher than that of Ser113, the matching residue to the
covalently bound serines of the known amidases.
Furthermore we show that AMI1 lacks the intrinsic
bifunctionality of other family members. Where other
amidases show in addition to the hydrolysis of amides an
esterase or peptidase activity, AMI1 does not exhibit such a
secondary catalytic property.
P19: 11
Interaction between auxin and cytokinin in the cell cycle
regulation
Hartig K., Beck E. and Fuchsberger K.
university of Bayreuth, Germany; [email protected]
Auxin and cytokinins to be considered as the essential
hormones in respect to the plant cell division, however the
understanding of their interaction is being still under cover.
Working with tobacco BY-2 cells enables synchronization
of the cell cycle and therefore offers the possibility to
detect phase-specific effects and regulation. BY-2 cells
represent meristematic root cells, which means their cell
division depends like a root on the external supply with
auxin, but is autotrophic in respect to cytokinin. Auxin
depletion on the one side results in a accumulation of cells
at the G2/M transition, which could be compensate by a
parallel application of cytokinin. On the other side artificial
enhanced cytokinin levels also induce G2/M arrest, could
be compensate by a parallel application of auxin. This
findings suggests that auxin is able to influence cytokinin
biosynthesis as well as cytokinin degradation. The
consequences
of
over
expressed
cytokinin
oxidase/dehydrogenase (AtCKX4) in tobacco BY-2 cells
showing that there must be a feed-back regulation from
cytokinin to the auxin metabolism too. Beside decreased
endogenous cytokinin levels, this cells are characterized by
enhanced endogenous auxin levels and by a modified
response to extern supplied auxin. Moreover this cells
showing a higher cell division activity, accompanied by a
stronger cell polarity, and a suppressed cell elongation. The
presented results demonstrate that the interaction between
auxin and cytokinins in the cell cycle regulation takes place
on the level of hormone metabolism.
P19: 12
Jasmonates in cut side shoots from Petunia hybrida
Lischewski S. and Hause B.
IPB Halle, Germany; [email protected]
The vegetative propagation of ornamental plants is
economically important. A great part of such plants are
produced by cutting lateral side shoots from stock plants.
By this procedure plant is wounded and a wound response
is caused in the harvested side shoots. Due to the fact that
jasmonates are known as central mediator of the plant
response against wounding, we analysed the jasmonate
biosynthesis in cuttings of P. hybrida.
Jasmonates are products of the octadecanoid pathway. A
key enzyme of this pathway is the allene oxide cyclase
(AOC). The cDNA coding for PhAOC consists of 946 bp
and codes for a protein of about 26 kDa, which contains a
putative signal peptide cleavage side. Because of its high
similarity to tomato AOC (LeAOC), we tested an antibody
raised against LeAOC via immuno blot showing that the
LeAOC antibody is able to recognize the PhAOC. By the
use of an immuno cytological approach it has been shown
that the PhAOC is localized in plastids of vascular tissue.
Immuno blot analyses demonstrated that the PhAOC levels
are increased transiently in cuttings after harvesting. This
increase was accompanied by increased transcript
accumulation of the PhAOC as revealed by real-time RTPCR. Moreover, the accumulation of jasmonic acid (JA)
and oxo-phytodienoic acid (OPDA) were monitored in
different parts of cuttings. JA increased transiently in
leaves and stems, whereas OPDA increased transiently in
stems of cuttings only. The putative function of jasmonates
in the formation of adventitious roots as a prerequisite for
vegetative production of plants will be discussed.
P19: 13
Reactive oxylipins inhibit cell division and growth and
induce their own detoxification
Berger S., Müller S., Dückershoff K. and Müller M.
Universität Würzburg, Germany; [email protected]
The enzymatically formed oxylipins jasmonic acid (JA)
and 12-oxo-phytodienoic acid (OPDA) are important
signalling compounds involved in plant development and
stress responses. Phytoprostanes are non-enzymatically
formed oxylipins with structural similarity to OPDA and
unknown function. Microarray analyses revealed that
phytoprostanes induced the expression of genes related to
detoxification, stress responses and secondary metabolism
and repressed genes related to cell division and growth. In
agreement with gene regulation, treatment with
phytoprostanes and OPDA inhibited cell division and root
growth. Gene regulation by different phytoprostanes and by
OPDA was highly similar but showed only low similarity
to gene regulation by JA.
OPDA and some phytoprostanes contain a reactive
carbonyl structure. The up-regulation of genes related to
detoxification by these oxylipins suggests that the encoded
proteins could be involved in detoxification of reactive
compounds including phytoprostanes and OPDA.
Heterologous
expression
revealed
that
indeed
phytoprostanes and OPDA comprise substrates for these
enzymes. The products of these reactions were detected in
planta.
To identify signal transduction mechanisms mediating the
response to oxylipins, promoter regions of induced genes
were analysed and shown to contain binding sites for TGA
transcription factors with high frequency. Induction of
several genes by OPDA and phytoprostanes was decreased
in knock out mutants in these transcription factors. These
results indicate that TGA transcription factors are involved
in oxylipin signalling.
POSTER ABSTRACTS
63
P19
P19: 14
Regulation of plastid transcription: cytokinin effects
Hertel S.
Humboldt University of Berlin, Institute for
Biology/Genetics, Germany; [email protected]
Cytokinins are involved in many developmental processes
during plant growth, such as in the control of chloroplast
biogenesis and function of young seedlings. However, it is
not yet understood how this phytohormone unfolds its
effect on plastids. At least in part, responses of plastids to
cytokinin may result from inducing the expression of
nuclear genes encoding chloroplast proteins. Furthermore,
since plastids possess their own genome and expression
machinery, cytokinin may also directly affect the
expression
of
plastid
genes
at
all
levels.
We are studying the effect of cytokinin on transcription of
chloroplast genes and nuclear-gene encoded components
involved in plastid transcription in Arabidopsis and
tobacco.
The seedlings were treated with cytokinin for 15, 120 and
180 min. Transcriptional changes of plastid-encoded genes
were analyzed using run-on assays. The investigation
revealed the most pronounced effect of cytokinin on plastid
gene transcription 120 min after hormonal treatment. We
also analyzed the accumulation of respective transcripts
from chloroplast RNA polymerases by quantitative realtime RT-PCR. All tested genes (e.g. RpoTp, RpoTm,
RpoB) were rapidly upregulated in their transcript
abundance after hormonal application. Our data
demonstrate effects of cytokinin on chloroplast gene
expression at the level of transcription and transcript
accumulation. Interestingly, the cytokinin-induced increase
in transcript levels preceded the stimulation of
transcription.
P19: 15
Regulatory network for auxin-controlled developmental
programs in Physcomitrella patens involving miR 160,
PpARF1 and PpGH3-2
Seumel G., Baar K., Reski R. and Frank W.
University of Freiburg, Germany;
[email protected]
In Physcomitrella patens knowledge about specific
members of the auxin signal transduction pathway is still
missing. ARFs present a class of transcription factors
which interact with IAA proteins. Released from the IAA
proteins in response to auxin they act as positive or
negative regulators of early auxin response genes
(e.g.GH3). In Arabidopsis, ARF10, 16 and 17 are regulated
by miRNA160. Recently, homologs of miR160 were
identified in Physcomitrella which target two mRNAs
encoding ARF proteins. Furthermore, miR160 expression
levels are stimulated by auxin suggesting a direct role in the
auxin response. For the functional analysis of one of the
ARF genes (PpARF1) the miR160 binding site within the
ARF coding sequence was mutated and used to generate
PpARF1 mutant lines by means of homologous
recombination. The mutation of the miR160 binding site
abolished the cleavage of the PpARF1 mRNA which was
accompanied by elevated PpARF1 mRNA levels.
Furthermore, we observed elevated mRNA levels of the
gene PpGH3-2 encoding an auxin conjugating enzyme
suggesting PpGH3-2 to be a direct target of PpARF1. The
PpARF1 mutants show phenotypic deviations including
enhanced branching of protonema filaments. Measurements
64
POSTER ABSTRACTS
of endogenous auxin levels in PpARF1 mutants and wildtype plants are on the way. Based on our data we propose a
regulatory network involving miR160, PpARF1 and
PpGH3-2 controlling auxin-regulated development in
Physcomitrella.
This work was supported by the Landesstiftung BadenWürttemberg and by the BMBF (Freiburg Initiative for
Systems Biology).
P19: 16
Role of nitrilase for the biosynthesis of auxin in rice
(Oryza sativa).
Lee Y.1, Oh Y.1, Hwang I.1, Kriechbaumer V.2,
Glawischnig E.2 and Park* W.1
1
(Republic of); 2Lehrstuhl fuer Genetik, Technische
Universitaet Muenchen, Am Hochanger 8, D;
[email protected]
Indole-3-acetic acid (IAA) is the major natural auxin and
regulates diverse developmental processes including rootand shoot-patterning as well as cell elongation. IAA has
been suggested to be synthesized at least partly from
indole-3-acetonitrile (IAN) via the reaction catalyzed by
nitrilases (EC 3.5.5.1) in Arabidopsis and maize. In rice,
there are two genes of nitrilases on the chromosome 2,
OsNIT1 and OsNIT2, whose functions have not been
elucidated. The inhibition of rice root elongation by
exogenously applied IAN indicated an active conversion of
IAN to IAA, suggesting action of nitrilases. The expression
of both rice nitrilases was detected by RT-PCR, and was
most abundant in the root tip and leaves. The distribution of
nitrilase proteins observed by Western analysis appeared
with the same pattern of nitrilase transcripts. In addition,
endogenous nitrilase enzyme activities were observed in an
assay measuring the produced IAA form IAN based on
reverse-phase C18 HPLC. However, the in vitro activity of
recombinant OsNIT1 and OsNIT2 enzymes were not
observed in bacterial crude extracts containing
heterologously expressd proteins. Purified fractions using
Ni-NTA columns did not show any activity, either. We will
discuss the possibilities that can explain current problems.
P19: 17
The biosynthesis of indole-3-acetic acid (IAA) via an
indole-3-acetamide hydrolase (AMI1) in Arabidopsis
thaliana
Lehmann T., Neu D. and Pollmann S.
Ruhr Universität Bochum, Germany; [email protected]
Indole-3-acetic acid (IAA) is the major representative of
the phytohormone group of auxins. Although a broad range
of knowledge about physiological and molecular
mechanisms of IAA-action was observed in the past, our
understanding of IAA-biosynthesis remains fragmentary.
Up to date, there is only one completely unraveled pathway
for IAA-biosynthesis which is utilized by plant associated
bacteria like Agrobacterium or Pseudomonas. There, the
proteinogenic amino acid L-tryptophan (L-Trp) is
converted to indole-3-acetamide (IAM) via a tryptophan-2monooxygenase (iaaM). Afterwards IAA is synthesized by
a hydrolysis of IAM utilizing an IAM hydrolase (iaaH).
It was thought that this pathway is restricted to bacteria, but
we were able to detect endogenous IAM in sterile grown
seedlings of Arabidopsis. Furthermore, we could identify
P19/P20
and overexpress an IAM hydrolase (AMI1) from A.
thaliana capable of converting IAM to IAA in vitro.
By cloning GFP fusion constructs and using the technique
of Confocal Laser Scanning Microscopy we were able to
show that AMI1 is localized in the cytoplasm, thus, in the
putative location of IAA-synthesis. In addition we showed
by using RT-PCR and by detection of protein-levels using
an AMI1-antibody that AMI1 is highly expressed in
inflorescences, young leaves and siliques. Hence, in tissues
with meristematic activity and places with the highest IAA
contents, as judged by GC-MS MS experiments.
P19: 18
The effect of low atmospheric moisture on abscisic acid
accumulation in woodland herbs
Lendzion J.1, Ratzinger A.2, Karlovsky P.2 and
Leuschner C.1
1
Plant Ecology, University of Göttingen, Germany;
2
Molecular Phytopathology, University of Göttingen;
[email protected]
Abscisic acid (ABA) is known to control plant growth and
leaf development under soil drought. Besides the effect of
soil drought on plant growth and leaf development, it has
been reported that high levels of the water vapor saturation
deficit of the air (vpd) have similar negative influences as
low soil moisture. Nevertheless, there has been no research
focusing on the question if ABA is also accumulated in
plants grown under high vpd levels but ample soil moisture.
We tested the hypothesis that high vpd levels increase ABA
in plants, independently from soil moisture, by
experimentally exposing two woodland herb species
(Mercurialis perennis and Stachys sylvatica) to variable
vpd levels in climate chambers with hydroponic cultures.
We measured ABA accumulation in leaves and roots,
biomass production, leaf development and water relations
at different times of the experiment.
In both woodland herb species the concentration of ABA in
leaves and roots was higher in plants grown under elevated
vpd levels than in plants grown under low vpd levels.
Plants (of both species) grown in dry air treatments showed
a significantly lower biomass production as well as a
reduced leaf area and leaf number. Our result implies that
ABA was involved in the regulation of growth and leaf
development in the two investigated herb species. The
accumulation of ABA in this study was induced by an
atmospheric water deficit, and not by a soil water deficit,
which indicates that elevated vpd levels can produce stress
for plants that depend on high air humidity, and this
independently from soil moisture.
P19: 19
The GH3-gene family of Arabidopsis thaliana: Auxin
and the obligate pathogen Plasmodiophora brassicae
Horn C., Siemens J. and Ludwig-Müller J.
TU Dresden, Germany; [email protected]
The GH3-gene family might play a role in clubroot disease
development caused by Plasmodiophora brassicae. Some
of these family members conjugate auxin by adenylation
with an amino acid and showed an upregulation during
clubroot infection as determined by microarray and RTPCR. No differences could be detected between wildtype
and single KO-mutant plants of highly regulated GH3genes in their susceptibility to the pathogen. Therefore,
single KO-lines were crossed in different combinations but
in the F2 populations no homozygous double KO-lines
could be detected, indicating important general functions of
GH3 genes. Furthermore the single KO-mutants were
treated with different IAA concentrations and their root
growth was measured. From 3 of this mutants the conjugate
content was determined via GC/MS-technique. A more
defined control of regulation is intended to be achieved by
antisense constructs, which were made for the two most
upregulated GH3-genes to specifically repress the
expression of GH3-genes in infected roots. Expression of
the antisense constructs is controlled by two root specific
promoters which were tested with a reporter gene fusion
showing induced gene expression during clubroot infection.
The testing and characterisation of the transformants is in
progress. With a pathogenesis-inverse control of auxin
homeostasis it is expected to produce an unspecific
resistance against the obligate parasite which could also be
transferred into rapeseed and cabbage.
P20: PLANT GENOMICS
P20: 1
Cell type specific analysis of the response of Arabidopsis
thaliana to oxygen deficiency stress
Mustroph A., Zanetti E., Branco-Price C. and BaileySerres J.
University of California Riverside, United States of
America; [email protected]
As multicellular organisms plants consist of differentiated
cell types. Gene expression varies between cell types of
individual organs under normal conditions; the response to
environmental stress at the cell-specific level is poorly
characterized. Gene expression is often monitored by
profiling steady-state mRNA content. However, cell-type
specific patterns of gene expression are obscured when
RNA is isolated from homogenates of multicellular organs.
Moreover, the assessment of total mRNA content provides
no information on the amount of the transcript that is
associated with ribosomes. We have developed a method to
isolate cell-type specific mRNA populations from crude
cell extracts of Arabidopsis thaliana. The use of transgenic
Arabidopsis plants that express a His6-FLAG epitopetagged ribosomal protein under different cell-type specific
promoters enables the isolation of polysomes by
immunoprecipitation with anti-FLAG antibodies and
therefore the enrichment of specifically translated mRNA.
With this method, we observed the rapid and dynamic
response of Arabidopsis seedlings to oxygen deficiency.
Polysomal mRNAs from different cell types were extracted
by immunoprecipitation from root and shoot tissue and
used in microarray hybridizations. This approach has
exposed a set of core genes which are induced in all cell
types, as well as cell-type specific mRNAs. The core
response group includes genes encoding enzymes important
for metabolic processes that sustain cellular homeostasis.
(Supported by funds from the NSF; DAAD for A.M.)
P20: 2
Characterization of WRKY transcription factors in
barley (Hordeum vulgare)
Mangelsen E.1, Kilian J.2, Kolukisaoglu Ü.3, Harter K.2,
Jansson C.1 and Wanke D.2
1
Dept. of Plant Biology and Forest Genetics, SLU Uppsala;
2
ZMBP, Dept. of Plant Physiology, Tuebingen University;
3
CELISCA, Center for life science automation, Rostock;
[email protected]
POSTER ABSTRACTS
65
P20
WRKY proteins constitute a family of zinc-finger
transcription factors that are characterized by a conserved
~60 amino acids spanning DNA-binding domain, the
WRKY-domain. Based on structural features, WRKY
proteins can be divided into three major groups and
subgroups. Phylogenetic analysis revealed a monophyletic
rigin from basal eukaryotes and enormous radiation events
in higher plants, which might account for their enrolment in
adaptation to biotic and abiotic stresses. Yet, there have
been 72 and 81 WRKY genes identified for the model plant
species Arabidopsis thaliana and Oryza sativa,
respectively. For the cereal crop barley, three WRKY
proteins have been described so far. Hence, we have to
assume that the majority of barley WRKY proteins
remained uncharacterized until now. Using the publicly
available sequence information, we identified a minimum
number of 45 barley WRKY (HvWRKY) proteins.
Comparative phylogenetic analysis of HvWRKYs and
WRKY proteins from Arabidopsis and rice identified
clusters of orthologous and paralogous WRKY proteins for
all three major groups. Strict clusters of only rice and
barley WRKY proteins indicate a monocot-specific
radiation for some of the subgroups. We used publicly
available microarray datasets to monitor gene expression
for the 20 barley WRKY genes. Based on this data we
conclude HvWRKYs being involved in both, plant
development and response to biotic stresses. We are
currently performing in situ hybridizations to further
investigate the localization of transcripts of a subset of
barley WRKY genes on a sub-organ level.
P20: 3
Functional characterisation of ABS and AGL63 in
Erdmann R.
The development of whorls out of the floral shoot meristem
in Arabidopsis is guided by different floral organ identity
genes. The outer whorl forming leave like structures called
sepals is determined by A-class genes. The second whorl
consisting of usually attractively coloured petals is due to
the combined activity of A-, B- and E-class genes. The
third whorl is specified by B-, C-class and E-class genes
expression leading to the formation of stamen. The fourth
whorl forms the female reproductive organ. Carpels are
specified by the expression of D- and E-class genes. B, C,
D and E class genes are all transcription factors belonging
to the MIKC-type subfamily of MADS-box genes.
Expression studies prove that genes with putative combined
C/D function are specifically expressed for reproduction
and the putative B function genes are restricted to the male
reproductive organ. A sister clade of B genes, termed
Bsister (Bs), were reported by Becker et al. 2002.
Expression studies revealed that Bs genes are mainly
transcribed in female reproductive organs (ovules and
carpels). Analysis of the abs knock out mutant showed an
altered seed pigmentation and endothelium malformation.
The relatively mild phenotype of the abs mutant led to the
hypothesis that there might be another gene acting
redundantly to ABS. One good candidate is AGL63, the
gene most closely related to ABS. However, AGL63 shows
deletions in the K and C domain and we can show that it is
rather weakly expressed. We aim to establish if AGL63 is a
pseudogene or if it has function and possibly acts
redundantly to ABS.
66
POSTER ABSTRACTS
P20: 4
Functional Specificity of 14-3-3 Proteins?
Rauch S., Gross-Hardt R. and Oecking C.
Uni Tübingen/ZMBP Pflanzenphysiologie, Germany;
[email protected]
The 14-3-3 proteins constitute a family of highly conserved
proteins present in all eukaryots. They form dimers that can
interact in a phosphorylation dependent manner with
cellular proteins thereby modifying them in different ways
e.g. enzymatic activity, localization. In mammals, there are
at least seven isoforms, two have been identified in yeast
and Drosophila and up to 15 isoforms are present in plants.
In Arabidopsis 13 expressed isoforms can be divided into
two major phylogenetic groups, the ε and the non-ε group.
Interestingly, phylogenetic analyses reveal that animal ε
members as well as yeast isoforms cluster together with the
plant ε isoforms, but the non-ε groups are distinct from
each other. This indicates that ε developed before the split
into major kingdoms, while the non-ε groups have
developed independently, possibly fulfilling organism
specific functions. Analyses of T-DNA insertion lines from
Arabidopsis revealed a 14-3-3ε mutant with a severe
phenotype. Only heterozygous mutants could be isolated
and they show a sterility of approx. 60% while the wild
type has a sterility rate of approx. 12%. This indicates that
the transition of the mutated gene through one of the
gametophytes is impaired. Further investigation suggests
that the development of the female gametophyte is arrested
at the first haploid stage. These results collectively imply
that 14-3-3ε might be responsible for the regulation of
fundamental enzymes present in all eukaryotic organisms
and is therefore essential for cell survival.
P20: 5
Gender determination in aspen (Populus tremula L.)
Pakull B., Markussen T. and Fladung M.
Bundesforschungsanatalt für Forst- und Holzwirtschaft,
Gender determination in aspen (Populus tremula L.) :Finemapping of sex-correlated markers, identification and
characterization of sex-determining genes
In the last 20 years a large number of genetically modified
trees have been produced. The commercialisation of e.g.
transgenic poplar is on the way in many countries.
However, the poplar species are dioecious and thus obligate
outcrossers. For future plantation forestry not only clones
but also sexual derived progenies of transgenic poplar will
be used as plant material.To avoid undesired gene flow the
identification of gender before the tree will naturally start
to flower after 6-10 years, will be helpful in either biosafety
matters or sterility research. In an ongoing search for sexcorrelated molecular markers (AFLPs and SSRs) a single
locus correlating to gender (“G-locus”) in Populus was
mapped on linkage group 5 of a preliminary consensus map
of P. tremula x P. tremuloides. Using SSRs for aligning the
gained data with other genetic maps of the genus Populus,
some of them with a sex-correlated region mapped on LG
XIX (P. tremula: Meyer et al. submitted; P. nigra: Gaudet
et al. 2006 and P. trichocarpa: www.populusgenome.org)
will hopefully support this search. Final aim is the
screening of an already constructed BAC-library of the
male parent and the construction and characterization of a
BAC-Contig containing the sex-correlated region, that will
hopefully lead to the identification of potential sexdetermining genes and the development of sex-specific
molecular markers.
P20
P20: 6
Genetic interactions of N-glycosylation mutants cgl1
(complex glycan 1) and stt3a (staurosporin and
temperature-sensitive 3a) in Arabidopsis thaliana
Frank J.1, Rips S.1, Kaulfürst-Soboll H.1, Koiwa H.2 and
von Schaewen A.1
1
Westfälische Wilhelms-Universität Münster, Germany;
2
Vegetable and Fruit Improvement Center, A&M
University Texas, USA; [email protected]
We have compared three Arabidopsis complex glycan
(cgl1) mutants and report on their genetic interaction with
stt3a. A catalytic subunit of Oligosaccharyltransferase
(STT3a) controls in the ER lumen the transfer of core Nglycans to nascent secretory proteins. Arabidopsis cgl1
mutants C5 and C6 lack N-Acetyl-Glucosaminyltransferase
I (GnTI) activity in the Golgi and are unable to form
complex glycans (von Schaewen et al., 1993).
For C5 we confirmed a second N-glycosylation site created
by a point mutation (Strasser et al., 2005). For C6 we newly
established that a point mutation shifts the 3’-splice site of
one intron, which results in alternative splicing and causes
frame shifts. For cgl1-T we show that a single T-DNA copy
resides in intron 11, which also abolishes complex glycan
formation.
Introgression of the stt3a-2 allele, known to mediate
infrequent glycosylation of secreted proteins in Arabidopsis
(Koiwa et al., 2003), restored complex glycan formation in
C5 stt3a-2 but not in C6 stt3a-2 or cgl1-T stt3a-2.
Therefore, synergistic effects of combining the two Nglycosylation mutants were observed for C6 stt3a-2 and
cgl1-T stt3a-2 only, as revealed by root growth assays. Our
analyses show that only the two newly characterized C6
and cgl1-T are true cgl1-null mutants.
P20: 7
Isolation of Benzenoid Methyltransferases from
different Solanaceae leads to new insights in evolution
of genes involved in floral scent production
Krohn K., Hippauf F., Feike J. and Piechulla B.
University of Rostock, Department of Biological Sciences,
Biochemistry; [email protected]
Benzenoid carboxyl MT catalyze esterification for
synthesis of volatile compounds using SAM as methyl
donor and SA and/or BA as methyl acceptor. Important
products (MeBA, MeSA) are known to serve as pollinator
attractants in many plants and MeSA is involved in
pathogen defence.
Two types of benzenoid C-MTs can be distinguished by
sequence comparison and biochemical characterization.
SAMT-type has a high catalytic activity with SA and
amino acids of the catalytic pocket are highly conserved.
The BAMT-type exhibits similar Km values for both
substrates and in planta higher efficiency with BA. The less
conserved amino acids important for substrate recognition
differ from the SAMT-type. Site directed mutagenesis was
used to alter amino acids of active pocket, e.g. Met 158 to
His, Met 218 to Leu, Leu 234 to Trp. Specific acitvities and
substrate spectra of the mutant proteins turned out that Met
158 to His is important for SA/BA discrimination, while
Ser 344 to Phe opens the active pocket for larger substrates.
The emission of MeSA and MeBA from flowers is
resricted to only a few members within the Solanaceae and
so it seems to be an evolutionary young trait. Both
benzenoid MT types could be isolated from Solanaceae
flowers, SAMT type from Datura wrightii and BAMT from
Nicotiana suaveolens. To learn more about the origin of
respective genes, benzenoid-MTs of different Nicotiana
species and Cestrum nocturnum were isolated.
Phylogenetic trees were constructed, enzymes were
biochemically characterized and the active pocket was
related to the enzyme’s function.
P20: 8
Regulation of gene expression in roots of cabbage
varieties differing in root hair growth under Pdeficiency
Bremer M. and Schenk M.
Institute of Plant Nutrition, Leibniz University Hannover,
Plants respond to low phosphorus with adaptive changes in
biochemical and molecular mechanisms and in root
morphology. In Ethopian mustard (Brassica carinata)
different phosphorus efficiency was attributed to longer
root hairs in the P-efficient cultivar. The presented study
aims to identify differences in the gene expression of two
cabbage varieties under P-deficiency by means of
Suppression Subtractive Hybridization (SSH). This method
resulted in a subtracted cDNA library with differentially
expressed genes. The resulting gene sequences were
verified for differential expression by semi-quantitative
RT-PCR with gene-specific primers and specified by
corresponding homologous sequences in databases.
Another approach was the use of whole genome
microarrays of Arabidopsis thaliana. The taxonomic
relationship enabled the hybridization of Brassica carinata
cDNA to sequences of this completely studied plant.
Differentially expressed sequences revealed genes involved
in cell wall synthesis and cell extension that were
upregulated in the P-efficient cultivar compared to the more
inefficient cultivar during P deprivation. Sequences with a
higher expression in the inefficient variety had similarities
to cell wall proteins and to genes that are responsible for
determining the epidermal cell pattern. The effect of these
genes on root hair elongation under P-deficiency is
discussed.
P20: 9
The 14-3-3 family: diversity versus redundancy
Weckermann K. and Oecking C.
ZMBP Pflanzenphysiologie, Germany;
[email protected]
Members of the eukaryotic 14-3-3 family are highly
conserved proteins that are involved in the regulation of
several signal-transduction pathways by protein-protein
interactions. They bind to pS/pT motifs in a sequence
specific manner thereby inducing a change in the activity
state of the respective target protein. Arabidopsis has
thirteen 14-3-3 genes which can be divided into two major
phylogenetic groups, the epsilon and the non-epsilon group,
the latter consisting of three subgroups. The amino acid
residues involved in binding of the phosphorylated
consensus motif are highly conserved among all isoforms,
which would suggest that they exhibit similar functional
properties. However, the N- and C-termini are nearly
unique to each isoform. Consequently, the question arises
as whether particular 14-3-3 isoforms have distinct
biological functions. Expression of genomic 14-3-3:GFP
fusions in Arabidopsis revealed tissue-specific expression
patterns for some of the genes analyzed. However, the
expression of the majority of the isoforms occurs in neither
a tissue-specific nor developmentally regulated manner.
POSTER ABSTRACTS
67
P20/P21
Thus differences in expression patterns seem not to
contribute to possible isoform specificity. Furthermore,
transgenic lines which allow ethanol-inducible RNAi based
gene silencing of all 14-3-3 members constituting one
phylogenetic subgroup were analyzed. According to our
results, 14-3-3 isoforms belonging to different subgroups or
groups show certain specificity.
P20: 10
The AtGenExpress wounding experiment: Expression
changes during wounding stress reveal the involvement
of three mayor transcription factor families
Wanke D., Kilian J., Berendzen K. and Harter K.
ZMBP-Plant physiology, Tuebingen University, Auf der
Morgenstelle 1,Germany; [email protected]
Mechanical wounding of a plant leaf is known to induce
several signaling cascades to respond towards the water
loss on the one hand and the potential threat of a pathogen
infection on the other. The destruction of the plant tissue
has to be repaired, the uncontrolled water loss and ion
leakage must be stopped and a sound defense network of
partially preformed disease resistance factors have to be
activated.
The use of specific synthetic promoter-reporter gene
constructs supports an involvement of several different
signaling cascades triggering an concerted wounding
response. Transcription factors mediate these expression
changes by binding to their cognate cis-regulatory element
in order to integrate the incoming signals. By analyzing the
transcriptome after wounding, we could clearly distinguish
an early and late phase of response. Moreover, the wound
signal is transduced from the leaf (where the treatment was
performed) to the untreated roots, where a similar set of
genes was regulated with a delayed responsiveness.
Hierarchical clustering of the regulated genes resulted in
sets of genes involved in the early and late phase response,
which are enriched for transcription factors of the bZIP-,
WRKY- and AP2/EREBP-transcription factor families.
Accordingly, binding sites of these factors were frequently
detected in the upstream sequences of the responsive genes.
P20: 11
The plant specific BPC/BBR family of GAGA-repeat
Binding proteins
Hohenstatt M.1, Hummel S.1, Kilian J.1, Kolukisaoglu
Ü.2, Berendzen K.1, Harter K.1 and Wanke D.1
1
ZMBP-Pflanzenphysiologie, Universität Tübingen, Auf
der Morgenstelle 1, 720; 2CELISCA (Center for Life
Science Automation), Friedrich-Barnewitz-Strasse 8;
[email protected]
BPC/BBR proteins comprise a novel class of transcription
factors that are confined to the plant kingdom. They have
recently been identified as essential key-regulators of
homeobox gene expression in barley.
BPC/BBR-proteins have been identified due to their
specific binding to a conserved element with its simple
sequence repeat consensus of (GA/TC)7 or higher. BBR
proteins have properties of animal GAGA-binding factors,
but they exhibit no sequence homologies to Trl and Psq of
Drosophila, which encode functionally analogous proteins.
So far three distinct regions could be identified common to
most BPC/BBR proteins: An N-terminal putative activation
domain, a NLS and a highly conserved domain at its Cterminus, which mediates DNA-binding.
68
POSTER ABSTRACTS
By structural means, the protein family can be subdivided
into two groups based upon their N-terminal domain.
Similarly, phylogenetic analysis based solely on the DNAbinding domain sequence strongly supports the division
into two distinct groups.
The basic DNA-binding domain, a 90 amino acid region, is
structured as a typical zinc-finger-like motif putatively
comprising two ß-sheets followed by an a-helix. A full
genome target site analysis of putative binding motifs
suggest a role in regulating other transcriptional regulators
or auxin related genes.
P21: PLANT INVASIONS
P21: 1
Feral oilseed rape in northern Germany: Persistence,
gene flow & hybridisation
Elling B., Müller M. and Neuffer B.
Uni Osnabrück, Germany; [email protected]
One of the most important sources for neophytes are plants
escaping from cultivation such as oilseed rape (Brassica
napus L.). Feral oilseed rape populations are frequently
found in ruderal habitats and can co-occur with several
close relatives such as B. rapa, B. oleracea, Raphanus,
Sinapis, Diplotaxis. Since 2004 feral Brassica populations
and the associated cruciferous flora have been monitored in
the area of Osnabrück (Lower Saxony, Germany). The aim
of the study is to reveal whether feral populations are
persisting and if gene flow between cultivated varieties,
feral populations and close relatives takes place with a
special focus on local conditions. Oilseed rape is an
amphidiploid hybrid and originated from the diploid
parental species turnip rape (B. rapa) and cabbage (B.
oleracea). Hybridisations between oilseed rape and turnip
rape are well known. In our study evidence of hybridisation
was provided by molecular (AFLPs, micosatellites) and
cytological analysis of a mixed population of both species.
Apart from ‘normal’ diploid B. rapa, several tetraploid
turnip rape populations were detected in the area under
investigation. To date, the crossing potential of these
tetraploid varieties with oilseed rape is virtually unknown
and a main objective of the present study. Feral populations
can serve as stepping stones for gene flow from cultivated
plants into close relatives and therefore promote the spread
of (trans-)genes into natural populations. Studying gene
flow is therefore a crucial aspect of the risk assessment of
transgenetic oilseed rape.
P21: 2
The worst aquatic weed worldwide – the beautiful water
hyacinth Eichhornia crassipes
Parolin P.1, Rudolph B.1 and Bartels S.2
1
Biozentrum Klein Flottbek, Univ. Hamburg, Germany;
2
Max-Planck-Institut für Evolutionsbiologie;
[email protected]
The water hyacinth Eichhornia crassipes (Mart.) Solms is
an aquatic floating plant in freshwater lakes and streams. Its
native range is the Amazon basin, but nowadays it is
introduced in most warm countries, first to decorate ponds
and gardens, but then it escaped into local environments
and has thus spread to more than 50 countries on five
continents. Nowadays, the water hyacinth is one of the
worst weeds in the world. Some cite the species as the
worst aquatic weed worldwide. Several introduction events
P22
are described in the literature and internet such as the rapid
spread out from a botanical garden in Java followed by a
fast invasion of parts of tropical Asia, an introduction to
Africa in 1880 and North America four years later. In the
present study, we analysed the genetic diversity of
populations in its native range and of invasive populations
worldwide, collected in South America (Argentina, Brazil,
Colombia, Peru, Uruguay), Asia (China, India, Laos),
Africa (Rep. Niger) and Europe (Germany). For
comparisons, the closely related co-occurring less invasive
E. azurea is analysed. Molecular analyses were carried out
using molecular markers such as AFLP and cpRFLPs from
237 individuals representing 17 populations worldwide.
Reproducible PCR products were integrated into a 1-0
matrix. From this matrix genetic distance trees were
estimated using PAUP*4.0b10. The UPGMA as well as
Neighbor Joining tree showed several independent
introductions worldwide, confirming worldwide weed
reports which postulate different sites and origins of
introductions.
P22: PLANT PATHOGENS
P22: 1
Factors responsible for HR formation in tobacco plants
challenged with avirulent bacteria (Pseudomonas
syringae)
Kapuganti J. and Kaiser W.
Julius-von-Sachs-Institute, University of Wuerzburg,
There has been increasing evidence that nitric oxide (NO)
plays a central role in plant-pathogen interactions. Vast
numbers of studies into the roles of NO focus on its effect
in promoting the hypersensitive response, but knowledge
about other factors besides NO which may affect bacterial
growth in the host are limited. Infiltration of avirulent
Pseudomonas syringae p.v. phaseolicola into tobacco
leaves of nitrite-reductase antisense transformants (which
produces high nitric oxide levels) leads to a more rapid and
severe HR compared to wild type. Similarily, growing
plants on ammonium as the sole N-source, which prevents
NO synthesis, delayed lesion formation. Weak and slow
lesion formation was expectedly correlated with high
bacterial growth. This might point to the classical role of
NO in the HR. However, we also analyzed apoplastic sugar
and amino acid levels, which were much higher in plants
grown on ammonium compared to nitrate-grown plants.
Thus, levels of organic nutrients in the host leaf apoplast
might also affect bacterial growth. Indeed, preliminary data
indicate that flushing ammonium-grown leaves with NO
does not affect bacterial growth. We are now also
determining H2O2 and salicylic acid levels and PR gene
expression in these plants to elucidate factors affecting this
incompatible plant-pathogen interaction.
P22: 2
Analysis of genes involved in Hs1pro1-mediated
resistance responses in the nematode (Heterodera
schachtii) resistant sugar beet (Beta vulgaris) by SSH
library
Menkhaus J., Ye W. and Cai D.
Molecular Phytopathology, Christian-AlbrechtsUniversität, Kiel, Germany; [email protected]
The Hs1pro1-locus confers resistance to the beet cyst
nematode Heterodera schachtii in sugar beet. To obtain
genes which are involved in the Hs1pro-1-mediated
resistance response suppressive subtractive hybridisation
(SSH) sequence tag libraries were constructed. Roots of
resistant and susceptible beets were harvested 3, 6 and 12
days after nematode infection and RNA isolated from
pooled roots. For up-regulated genes a forward and for
down-regulated genes a reverse subtractive EST library
was constructed. In total, 1166 ESTs from the forward- and
242 from the reverse-library were obtained, which
represent 368 and 105 unique genes respectively. Sequence
annotation revealed most of the ESTs as molecules with
known function on the NCBI database. From the forward
library 73% could be classified into various functional
groups including protein-synthesis (19%), cell rescue and
defense (17%), metabolism (14%), protein-destination
(5%), cellular transport (5 %), signal transduction (5%),
transcription (4%), cell division (2%), energy (2%) and
cellular organisation (0%). From the reverse library a
similar distribution of putative functional classes of
annotated ESTs was observed but with totally different
gene sets. By SSH technology more than 40 genes from the
forward library gave high homology to genes which are
already known to be involved in plant defence responses
including e.g. stress- and defense related proteins and
defensins indicating the complexity of the Hs1pro-1
resistance mechanism. Molecular characterization and
functional identification of genes are in progress.
P22: 3
Defense against Sclerotinia sclerotiorum in Arabidopsis
is dependent on JA, SA, ethylene, and ABA signaling
Guo X. and Stotz H.
Department of Horticulture, Oregon State University,
Corvallis, Oregon, USA; [email protected]
Genotypic differences in susceptibility of Arabidopsis
thaliana to Sclerotinia sclerotiorum have not been reported
due to the extreme susceptibility of this cruciferous plant.
To overcome this limitation, we have established
inoculation conditions that enable evaluation of differences
in susceptibility to S. sclerotiorum among Arabidopsis
mutants and ecotypes. Two coi1 mutant alleles conferred
hypersusceptibility to S. sclerotiorum. The plant defensin
gene PDF1.2 was no longer induced after challenging the
coi1-2 mutant with S. sclerotiorum. The npr1 and ein2
mutants were also hypersusceptible to S. sclerotiorum.
Induction of PDF1.2 and the pathogenesis-related gene
PR1 was reduced in ein2 and npr1 mutants, respectively.
Hypersusceptibility of coi1-2, ein2, and npr1 mutants to S.
sclerotiorum was not correlated with oxalate sensitivity.
Actigard, a commercial formulation of the systemic
acquired resistance inducer benzothiadiazole, reduced
susceptibility to S. sclerotiorum. Oxalate inhibited
pathogen- and abscisic acid-induced ROS production.
Oxalate production was associated with superoxide
formation during infection of Arabidopsis by S.
sclerotiorum. Hypersusceptibility to S. sclerotiorum of
abi1 and abi2 mutants was correlated with sensitivity to
oxalate and wilting.
POSTER ABSTRACTS
69
P22
expression data and possible functions of regulated proteins
will be discussed.
P22: 4
Analysis of fungal and bacterial populations in intact
and destroyed thatched roofs
Stockmeyer K.1, Schmitz-Streit R.2, Streit W.3 and
Kempken F.1
1
Abteilung Botanische Genetik und Molekularbiologie,
CAU Kiel; 2Institut für Allgemeine Mikrobiologie,
Christian-Albrechts-Universität Kiel; 3Abteilung für
Mikrobiologie, Biozentrum Klein Flottbek, Universität
Hamburg; [email protected]
Until the beginning of the 1980ths thatched roofs exhibited
a durability of about 35 years. In Northern Germany these
roofs are being destroyed increasingly and rapidly since the
last ten up to fifteen years through microorganisms and
today some of them already have to be covered new after a
few years. The reasons of this fast and dramatic reed
destruction are not yet understood. Certainly this problem
is complex and conditioned upon multiple factors. The
microbial degradation through fungal and bacterial
cellulases can be due to many factors such as modified reed
qualities and higher average temperatures.In order to
estimate the extent and nature of this problem, as a first
step we set out to analyse the fungal and bacterial
populations from a chosen number of roofs. During this
investigation the microbial populations from still intact and
damaged roofs will be compared. As the identification of
fungal and bacterial species under morphological aspects is
difficult and often even impossible, rDNA-sequences will
be amplified and sequenced employing universal primers.
Sequence comparisons with known species finally allows
for identification of the bacterial and fungal species found
in the samples.
P22: 5
Changes in European beech (Fagus sylvatica) gene
expression following infection with the root pathogen
Phytophthora citricola
Schlink K. and Vâlcu C.
Technische Universität München, Germany;
[email protected]
Pathogen induced changes in gene expression patterns are
investigated on transcript and proteome level in European
beech (Fagus sylvatica) seedlings infected with the
oomycete root pathogen Phytophthora citricola which
induces
root
necrosis
and
plant
wilting.
The plant defence response is analyzed locally (roots) and
systemically (leaves) at different stages of infection. The
experimental setup of infection experiments involves in
vitro infection of seedlings as well as infections in soil.
Within the first system we investigate both local and
systemic response to pathogen infection while the latter
experiments are used for the study of systemic response
under conditions close to the natural ones.
Transcript expression is analyzed based on a subtractive
cDNA library from infected roots using a multiplex custom
array system (ImaGenes, Berlin). And protein expression
patterns are characterized by means of two-dimensional
electrophoresis. For identification of protein spots that
respond to the pathogen infection mass spectrometry is
used.
More than one hundred beech protein spots were found to
exhibit significant changes in their expression levels
following infection with Phytophthora citricola,
approximately 75% of them up-regulated and 25% downregulated. The comparison of proteomic results to transcript
70
POSTER ABSTRACTS
P22: 6
Current diversity studies on plant pathogenic
cercosporoid hyphomycetes
Kirschner R.
Department of Mycology, Institute for Ecology, Evolution
& Diversity, J.W. Goethe-University, Germany;
[email protected]
Among phytopathogenic fungi, asexually sporulating fungi
(Fungi Imperfecti) show a high diversity similar to that of
rust fungi and mildews and cause comparable losses in
agriculture. Species of Cercospora and similar plant
pathogenic Fungi Imperfecti with relationship to sexual
Mycosphaerella spp. (Ascomycota) are called cercosporoid
hyphomycetes. A general pattern of geographical
distribution of genera can be proposed.
Though several hundreds of species are described in
cercosporoid hyphomycetes, our studies on these fungi in
Germany, Panama, and Taiwan show that we are still at the
beginning of understanding their diversity. Many new
species and geographical records mainly of the genera
Passalora, Pseudocercospora, and Stenella are still to be
described, especially in tropical countries. Our deficiency
of knowledge is evident by the fact that many species of
cercosporoid hyphomycetes are first reported on introduced
plants as their hosts, but unknown in areas of original
distribution of the hosts.
Morphologically differentiated appressoria and haustoria
are usually absent in cercosporoid hyphomycetes, but
recently a complex appressorium was found in the type
species of Cercosporella in Germany. First records of some
species for Germany in the Botanical Garden of
Frankfurt/M illustrate the need of diversity studies even in
Central Europe.
P22: 7
Interspecific recombinants from dual infection of
sunflower with Plasmopara halstedii and P.
angustiterminalis
Spring O., Hammer T., Tscheschner H. and Zipper R.
University of Hohenheim, Germany; [email protected]
Dual infections with genetically homogenous strains of the
sunflower downy mildew pathogen Plasmopara halstedii
recently resulted in mitotic derived recombinant offspring
showing phenotypic characteristics of both parental strains
[Spring & Zipper 2006]. Single sporangium lines of a
Metalaxyl-tolerant isolate of P. halstedii were now used for
dual infection in interspecific combination with P.
angustiterminalis, the downy mildew pathogen of
Xanthium strumarium [Komjati et al. 2007], which is
infective to highly resistant sunflower genotypes as
well. The infections led to asexually formed sporangia
which gave rise to a new phenotype combining the
characteristics of the parental strains. The new phenotype
showed the metalaxyl-tolerance of one parent and virulence
behaviour characteristic of the other. These features were
inherited and did not occur spontaneously when parental
strains were propagated separately. DNA fingerprints
showed characteristic differences between the patterns of
both the parental strains and the new phenotype. The latter
showed DNA pattern of P. halstedii with an additional
amplicon specific for P. angustiterminalis. DNA
sequencing in the recombinant phenotype confirmed its
P22
origin from P. halstedii and the identity of the additional
fragment with the homologous amplification product from
P. angustiterminalis. This is the first evidence for genetic
recombination through parasexual events in dual infections
of sunflower and Xanthium downy mildew pathogens.
P22: 8
Detection of putative biotic factors involved in the
dieback disease of sissoo (Dalbergia sissoo Roxb.) in
Bangladesh
Valdez N.1, Vogel S.1, Tantau H.1, Hoque I.2 and
Mühlbach H.1
1
University of Hamburg, Biocenter Klein Flottbek,
Germany; 2University of Dhaka, Department of Botany,
Bangladesh; [email protected]
Dalbergia sissoo Roxb. (sissoo, Indian Rosewood) is one
of the most important timber in South Asia. In recent years
Dalbergia sissoo has been severely affected by the so
called dieback disease. The dieback of sissoo is a
devastating disease occurring in Bangladesh as well as in
India, Nepal, Pakistan, and Afghanistan. The typical
symptoms of this disease are described as leaf necroses,
wilting, successive thinning of the crown, stag-headedness
and trunk lesions. Affected trees usually die within several
months. Fungi, bacteria and insects were reported to be
associated with the dieback syndrome, but the causal
agent(s) have not yet been identified. Our studies are
focused on the molecular detection of the putative causal
biotic agent(s) of the disease, including viruses, viroids,
bacteria, phytoplasms and fungi. Here we present results
from our approach to detect bacteria associated with
affected sissoo trees, using PCR analyses with conserved
rDNA primer pairs and sequencing. These studies revealed
the association of two genera of phytopathogenic bacteria,
namely Pseudomonas and Pantoea, with dieback of sissoo.
Using hypersensitive response (HR) assays on
Chenopodium quinoa, Nicotiana tabaccum cv Xanthi and
Solanum lycopersicum the phytopathogenic potential of the
bacterial isolates could be confirmed.
P22: 9
Lipid transfer proteins and their role during clubroot
disease
Jülke S. and Ludwig-Müller J.
TU-Dresden, FR Biologie, Inst. f. Botanik, Germany;
[email protected]
The obligate biotrophic protist Plasmodiophora brassicae
causes the clubroot disease which is the most damaging
within the Brassicaceae.
We have analysed the host gene expression during the
disease development using the ATH1 Affymetrix 22K
microarray. A high percentage of genes from the „seed
storage/proteinase inhibitor/lipid transfer protein“ family
were differentially expressed during disease development.
We have chosen the ten strongest differentially regulated
LTP-genes for further investigations.
Because of the histological observation that all
developmental stages of P. brassicae contain lipid droplets
and many reports indicating that lipid transfer proteins are
not only involved in „metabolic lipid transfer“ but also in
plant defence reactions against pathogens, it is very likely
that they play an important role during disease
development. They are therefore a major target to generate
clubroot resistant plants.
To confirm our microarray data we have analysed the host
gene expression at different time points during disease
development using RT-PCR.
In order to counteract the naturally occurring regulation in
infected roots we have generated transgenic Arabidopsis
thaliana plants which overexpress or silence one of the
differentially expressed LTP genes. In addition, we are
analysing ltp knockout-lines and the generated transgenic
Arabidopsis plants with regard to their phenotype, changes
in gene expression of the other LTP-family members and
disease development.
We will be also investigating the antimicrobial activity of
selected LTPs.
P22: 10
Developmental processes during sporulation of
sunflower downy mildew, Plasmopara halstedii
Hammer T., Selzer P. and Spring O.
Universität Hohenheim, Institut für Botanik (210),
The oomycete Plasmopara halstedii, the causal agent of
sunflower downy mildew, propagates by oospores and
asexually formed sporangia. The sporangia are attached to
branched sporangiophores emerging through the stomata of
the host plant. Only little is known yet about developmental
processes during sporulation of P. halstedii and particularly
on the karyological situation in sporangia. For many
experiments, however, genetically homogeneous strains of
the pathogen are required and it is crucial to know whether
they can be obtained from single sporangium infections or
whether the zoospores of a sporangium may have
heterokaryotic origin. Therefore, we investigated
sporangiophore formation and the movement of nuclei
during sporangium development of P. halstedii.
Microscopy revealed the time frame of sporangiophore
formation which ends with the expulsion of sporangia.
Movement of nuclei and formation of septa was monitored
using fluorescence dyes.
P22: 11
Distribution of Erwinia amylovora in susceptible and
resistant Malus domestica cultivars and in presence of
the bacterial antagonist Pseudomonas fluorescens Bk3
Schmoock S. and Gau A.
Leibniz Universität Hannover, Germany;
[email protected]
Fire blight, caused by the bacterium E. amylovora, is one of
the most destructive diseases for apple and pear trees.
In this study, the distribution of the pathogen on susceptible
and resistant M. domestica cultivars, and in presence of the
bacterium P. fluorescens Bk3, was investigated. Also the
performance of the commercially used strain P. fluorescens
A506 (Blight Ban A506) against E. amylovora was
compared to that of P. fluorescens Bk3 in dual culture tests.
Using a luciferase-marked E. amylovora strain, it was
possible to observe the pathogen on agarplates or in plants
with CCD-cameras in a non-destructive way.
The investigations revealed that on resistant M. domestica
cultivars, the bioluminescence of E. amylovora remained at
the site of infection and abated after a few days, while the
plants didn't show signs of fire blight. Otherwise on
susceptible cultivars, the pathogen invaded rapidly leaf
stalks and stem, and the plants had typical disease
symptoms.
The bacterial antagonists P. fluorescens A506 and Bk3
were able to inactivate E. amylovora on agarplates, which
POSTER ABSTRACTS
71
P22
was visible by the reduction of the bioluminescence to an
undetectable level within few days. P. fluorescens Bk3
could also control fire blight on plant level, if the fire blight
susceptible cultivar M. domestica Holsteiner Cox was
pretreated with the antagonist. The pathogen wasn't able to
spread, and the plants remained healthy.
The pre-treatment of M. domestica with the antagonist P.
fluorescens Bk3 seems to be a promising alternative to the
frequent application of antibiotics to commercial orchards.
P22: 12
Expansins and endo-1,4-β-glucanases are involved in
cell wall modifications in nematode induced syncytia
Wieczorek K.1, Hofmann J.1, Blöchl A.2, Szakasits D.1,
Bohlmann H.1, Cosgrove D.3, Kreil D.1 and Grundler F.1
1
University of Natural Resources and Applied Life
Sciences, Vienna; 2University of Vienna, Vienna;
3
Pennsylvania State University, University Park,
Pennsylvania; [email protected]
Root parasitism of the cyst nematode Heterodera schachtii
is characterised by the formation of syncytial feeding
structures. They are formed by the fusion of root cells
accompanied by local cell wall degradation and
hypertrophy. In this study we tested if wall-loosening
proteins, expansins and endo-1,4-β-glucanases (EGases),
are upregulated during syncytium formation in roots of
Arabidopsis. We screened a syncytium-specific cDNA
library for all known expansins and EGases. Expression of
ten expansins and seven EGases was detected in syncytia.
For AtEXPA1, -3, -4, -6, -10, -15 and -16 these results were
confirmed with promoter::GUS lines. sqRT-PCR showed
that AtEXPA3, -6, -8, -10 and -16 are upregulated in
syncytia and are not present in control roots. By use of
semi-quantitative and quantitative studies the upregulation
of seven EGases in syncytia was confirmed. Two of these
genes, AtCel2 and KOR3, are shoot-specific but show high
expression in syncytia at different developmental stages.
Treatments with sucrose, GA3 and NAA also induced their
upregulation in roots, but other hormones resulted in only
minor effects. As AtCel2 is related to degradation of the
cell wall matrix, we analysed the hemicellulose content in
syncytia. The measured values resembled the expression
pattern of AtCel2. In kor3 and cel2 T-DNA mutants an
impairment of growth conditions for nematodes could be
found. We conclude that syncytium formation involves the
specific upregulation of different expansin and endo-1,4-βglucanases, which take part in the cell growth and wall
disassembly in syncytia.
P22: 13
Fungal glycolipids are targets of plant antimicrobial
peptides
Warnecke D.1, Zäuner S.1, Albrecht S.1, Ternes P.1,
Hillig I.1, Wobbe T.1, Thevissen K.2, Zähringer U.3,
Heinz E.1 and Sperling P.1
1
Biocenter Klein Flottbek, University of Hamburg,
Germany; 2Centre of Microbial & Plant Genetics,
University of Leuven, Belgium; 3Research Center Borstel,
Lab group Immunochemistry, Borstel, Germany;
[email protected]
Glucosylceramides (GlcCer) are membrane lipids and
represent the unique glycosphingolipids which plants, fungi
and animals have in common. On the other hand, fungal
GlcCer shows a number of structural features that
distinguishes it from those found in mammals and plants.
72
POSTER ABSTRACTS
Recently, we have shown that fungal GlcCers act as targets
for plant antimicrobial peptides (defensins). The growth of
yeasts (e.g. Pichia pastoris) and of phytopathogenic fungi
was inhibited by RsAFP2, an antifungal peptide isolated
from radish seeds (Raphanus sativus). Genetically
manipulated strains, which lack GlcCer, showed resistance
towards the defensin.
The aim of this study is to elucidate the structural features
of fungal GlcCer, which are important for the interaction
with the antifungal defensin and for subsequent inhibition
of cell growth. Therefore, we cloned all genes and
characterized the corresponding enzymes which are
involved in the introduction of functional groups into
fungal GlcCer. Subsequently, knock-out mutants of P.
pastoris and pathogenic fungi have been generated to
obtain strains with unusual structural features of GlcCer.
Phenotypes and resistance/sensitivity of these mutants
towards the plant defensin will be reported.
P22: 14
Identification of expressed genes involved in Fusarium
head blight resistance of winter wheat by cDNA-AFLP
analysis
Mikolajewski S.1, Diethelm M.1, Wagner C.2, Hartl L.1,
Friedt W.2 and Schweizer G.1
1
Bayerische Landesanstalt für Landwirtschaft, Germany;
2
Justus-Liebig-Universität Giessen, Germany;
[email protected]
Fusarium head blight (FHB), mainly caused by Fusarium
graminearum and F. culmorum is a widespread and
destructive disease of wheat leading to drastic losses in
yield and quality due to mycotoxin contamination.
Although by mapping and QTL approaches several
chromosomal regions with quantitative effects on FHB
resistance have been identified, the underlying resistance
genes and their actual function are still unknown. The
objectives of this project are to identify and characterize
expressed genes involved in the host-pathogen interaction
against FHB, their validation by integration into the
existing QTL maps, and the development of functional
molecular markers to support breeding strategies regarding
Fusarium resistance. While the project part at the
University of Giessen is dealing with a bioinformatics
based candidate gene approach, the main focus at the LfL is
the analysis of Fusarium-induced differential gene
expression using cDNA-AFLP technique, an efficient and
sensitive method to display and compare whole transcript
profiles of inducible characters. As plant material initially
the parents of the segregating FHB mapping populations of
winter wheat Dream (res.) x Lynx (sus.) as well as G16-92
(res.) x Hussar (sus.) have been chosen. First results have
shown differential TDFs (transcript derived fragments)
after inoculation with Fusarium in resistant varieties as
well as TDFs indicating retarded gene expression in the
susceptible cultivars.
P22: 15
In vivo determination of spatial and temporal dynamics
of plant pathogen interactions by multifluorescence
imaging
Roitsch T., Hupp S., Bonfig K. and Schreiber U.
Universität Würzburg, Germany; [email protected]
The infection of plant tissues by pathogens is a highly
dynamic process in relation to the responses of the plant
and of the pathogen. However, the analyses by molecular,
P22
biochemical and microbiological methods is limitted by the
distructive nature and the requirement to integrate over a
certain area. To overcome these limitations, the method of
fluorescence imaging has been used to analyse the infection
of Arabidopsis thaliana by Pseudomonas syringae. A
commercially available chlorophyll fluorescence imaging
system has been upgraded so that it became possible to also
determine GFP and plant phenolics. Chlorophyll
fluorescence imaging proved to be highly senstive and
allowed to detect effects on photosynthesis prior symptom
development and to visualize heterogeneous responses. P.
syringae DC3000 was transformed with a constitutively
and stongly expressed GFP for noninvasive monitoring and
fluorescence emission was shown to corelate with the
bacterial number. It was possible to visualize both the
proliferation of the bacteria and the heterogenous
distribution within the infected region by imaging the GFP
fluorescence. UV-excited fluorescence imaging allowed to
visualize the accumulation of phenolic compounds as a
defence response and an indicator of secondary product
formation. The present study demonstrates that it is
possible to monitor and compare spatial and temporal
dynamics of the response of primary metabolism and
defence responses of the plant and the proliferation and
spread of the pathogens within the same sample.
P22: 16
Inhibition of fungal growth by the extracellular protein
fraction from the antagonistic bacterium Pseudomonas
fluorescens Bk3
Hossain M.1, Piotrowski M.2 and Gau A.3
1
Ashtown Food Research Centre, Ashtown, Dublin 15,
Ireland; 2Lehrstuhl für Pflanzenphysiologie, RuhrUniversität Bochum, D-44780 Bochum; 3Institut für
Botanik, Leibniz Universität Hannover, D-30419
Hannover; [email protected]
In previous studies the direct antagonistic effect of
Pseudomonas fluorescens Bk3 on conidial germination of
Venturia inaequalis, the causal agent of apple scab, have
been shown in dual culture tests. The present study
confirmed the inhibitory effect on the conidial germination
of V. inaequalis by using living whole cells, extracellular
protein fraction and individual proteins.
The bacterial suspension from growth in M9 minimal
medium with asparagine as the sole nitrogen and carbon
source and the supernatant showed up to 100% inhibition
of conidial germination after pre-incubation. Since the
supernatant contained at least 10 major proteins they were
separated on SDS-PAGE, extracted from the gel and
subsequently re-natured with guanidine. After re-naturation
individual proteins were applied on the conidia of V.
inaequalis to see their impact on the conidial germination.
Out of these 10 proteins 3 showed inhibitory effects (20-42
%). De novo sequencing of these 3 proteins were carried
out by ESI Q-ToF mass spectrometry and they were
identified as extracellular solute-binding protein,
extracellular alkaline metalloprotease and peptidoglycanassociated lipoprotein. A proteolytic activity in the
extracellular protein fraction could be detected with activity
staining using casein as a substrate. The hydrolyzing effect
is related to the identified extracellular alkaline
metalloprotease.
P22: 17
Role of genes involved in lipid transfer and desaturation
in crown gall formation
Klinkenberg J., Hedrich R. and Deeken R.
University of Würzburg, Julius-von-Sachs-Institute, Botany
I; [email protected]
Plant tumours, also referred to as crown galls, are induced
upon T-DNA integration into the plant genome by
oncogenic strains of Agrobacterium tumefaciens. Full
genome microarrays (22K) have revealed that crown galls
of Arabidopsis thaliana show dramatic changes in gene
expression. Among the strongest deregulated genes were
those encoding a stearoyl-acyl–carrier-protein desaturase
(S-ACP-Des) and two lipid transfer proteins (LTP). SACP-Desaturases catalyze a key step in biosynthesis of
unsaturated fatty acids of which SSI2 was shown to
modulate defence signalling pathways by altering the ratio
of saturated to unsaturated fatty acids. LTPs bind and
transfer lipids, such as fatty acids, and have antimicrobial
activity. Interestingly, dir1, a LTP-mutant, was affected in
establishing systemic acquired resistance. The aim of our
studies is, to unravel the potential role of these genes in
transformation of Arabidopsis by Agrobacterium, tumour
development and a potential functional connection between
LTP2 and S-ACP-Des. In a first approach, potential
regulators of transcription, according to the situation in
crown gall tumours, have been analysed. Up to now, auxin
and oxygen deficiency were found to be strong regulators
of gene activity. Further on we will show if the bacterial
pathogen itself or the integrated T-DNA influences LTP/SACP-DES expression. Tissue-specific and subcellular
localisation studies, in addition to loss of function analyses
will increase our understanding of the role of lipids in
pathogen-plant interactions, which we will discuss on the
meeting.
P22: 18
Sensitive and rapid detection of Alternaria fungi in
wheat using polymerase chain reaction
Langenkämper G., Hofmann A., Masloff S. and Zörb C.
Bundesforschungsanstalt für Ernährung und Lebensmittel,
Detmold, Germany; [email protected]
Alternaria species can cause important plant diseases and
can produce mycotoxins in infected plants that are
potentially harmful to humans and animals. Alternaria
toxins that have been detected in unprocessed wheat grains
include alternariol, alternariol monomethyl ether,
altenuene, altertoxins and tenuazonic acid. A polymerase
chain reaction (PCR) assay was developed for the detection
of Alternaria fungi DNA in wheat. Primers were designed
to amplify a 366 bp fragment of a single copy Alternaria
alternata endoxylanase. Endoxylanase primers did not
amplify DNA in Saccharomyces cerevisiae, several
Fusarium species, Claviceps purpurea, Penicillium sp.,
Aspergillus ochraceus, Cladosporium sp., and Triticum
aestivum, DNA fragments of the expected size were
obtained in A. alternata, A. dauci, Ulocladium sp., and
Phoma sp. These four taxa were denoted Alternaria group.
Using PCR, DNA of the Alternaria group was detected in
72 of 85 wheat samples. Real time PCR was performed to
quantify DNA of the Alternaria group in wheat. In 18
wheat samples analysed, the DNA concentration of the
Alternaria group ranged from 1.3 x 106 to 4.9 x 109 haploid
A. alternata genomes per g whole wheat meal. Species of
Alternaria as well as some of Ulocladium and Phoma can
produce different mycotoxins. The proposed real-time
POSTER ABSTRACTS
73
P22
PCR-system would allow a rapid and sensitive
quantification of fungal DNA of the Alternaria group,
including mycotoxin producing species. The main
application is to screen a large amount of wheat samples
simultaneously.
P22: 19
Stage specific investigation of gene expression during
clubroot disease using ‚Laser microdissection and
pressure catapulting’ (LMPC)
Schuller A.1, Kehr J.2 and Ludwig-Müller J.1
1
TU-Dresden, Institute of Botany, Germany; 2Max Planck
Institute for Molecular Plant Physiology, Golm, Germany;
[email protected]
accumulated as a carbohydrate buffer to compensate
changing solute uptake by the nematode and as long-term
storage during juvenile development.
P22: 21
The compatible and the incompatible interaction
between Arabidopsis thaliana and Plasmodiophora
brassicae.
Rehn F.1, Arbeiter A.2, Galfe N.1, Mukherjee O.1,
Reinhardt S.1 and Siemens J.1
1
Technische Universität Dresden, Germany; 2Freie
Universität Berlin, Germany; [email protected]
Obligate biotrophic plant pathogens like Plasmodiophora
brassicae establish an intricate interaction with their host
during at least some part of the infection process. The life
cycle of P. brassicae consists of two phases: the primary
phase, which is restricted to root hairs and the secondary
phase which occurs in the cortex and stele of roots and
hypocotyls and leads to abnormal development, including
pronounced cell enlargement and cell proliferation. During
the second infection cycle different developmental stages
of the pathogen (early young plasmodia, young plasmodia,
vegetative plasmodia, resting spores) are found in the
infected root at the same time. To understand the
relationship of host and pathogen on a molecular level it is
necessary to isolate and analyze host cells (Arabidopsis
thaliana) depending on the developmental stage of the
pathogen they enclose and the position of the infected cells
in different tissues of the root (cortex and stele). ‘Laser
microdissection and pressure catapulting’ (LMPC)’ with
paraffin embedded, infected A. thaliana roots was
performed to investigate stage specific gene expression.
Host cells containing young plasmodia close to the central
stele and enlarged host cells containing vegetative
plasmodia in the cortex region have been successfully
isolated using LMPC, as well as the corresponding control
cells. After RNA Isolation and cDNA synthesis pathogen
and host genes could have been amplified. Real Time PCR
analysis will be performed.
Arabidopsis thaliana is a host plant of the obligate
biotrophic root parasite Plasmodiophora brassicae, the
cause of clubroot. Since susceptible and resistant ecotypes
of A. thaliana have been identified, we have used ATH1
Affymetrix array to investigate host gene expression during
development of the disease in the compatible and
incompatible interaction. Seven days after secondary
infection young plasmodia of the pathogen were visible,
but host cell and root morphology were only slighly
changed in susceptible ecotypes. Local changes in the
cytokinin homeostasis by up-regulation of cytokinin
receptor and down regulation of cytokinin-oxidases
(CKXs) has been shown to be linked to pathogenesis.
AHK3/AHK4, a cytokinin receptor double mutant and the
CKX-overproducer (35S::CKX1) showed strongly reduced
gall sizes. This apparent locking of the pathogen is a hint,
that spreading and development of the pathogen are
dependent on cytokinin-mediated signal transduction and
physiological changes of the host cells. In contrast, resistant
ecotypes carrying the RPB1 resistance gene showed no
change in root morphology but necrotic spots at the root
surface. The dominantly inherited RPB1 gene mediates a
hypersensitive response like reaction to P. brassicae.
Genetic data revealed no influence of the hormones
salicylic acid, jasmonic acid and ethylene, but a mutation of
SGT1a reveals to be epistatic to RPB1. The comparison of
the genome wide expression data of the compatible and
incompatible interaction pinpoint to protein degradation as
important part of clubroot resistance mechanism.
P22: 20
P22: 22
Starch serves as carbohydrate storage in nematodeinduced syncytia in Arabidopsis roots
Hofmann J.1, Szakasits D.1, Blöchl A.2 and Sobczak M.3
1
Institute of Plant Protection, BOKU Vienna; 2Department
of Chemical Ecology and Ecosystem Research, Vienna;
3
Department of Botany (SGGW), Warsaw Agricultural
The plant parasitic nematode Heterodera schachtii induced
feeding sites (syncytia) in the roots of Arabidopsis thaliana
wherefrom it withdraws its required nutrients. Thus, these
feeding structures are well supplied with assimilates and
present strong sink tissues in the host plant’s transport
system. Previously, sucrose import into nematode-induced
syncytia has been studied and a high accumulation of
sucrose was found (Hofmann, et al., 2007). In the present
study we could show by HPLC and microscopic analyses
that syncytia additionally store carbohydrates as starch.
Further, we follow the gene expression of the starch
metabolic pathway by gene chip analysis and qRT-PCR.
Finally, we could give a functional prove of the importance
of starch synthesis for nematode development using TDNA insertion lines. We conclude that in syncytia starch is
74
POSTER ABSTRACTS
The quest for taxonomic markers – can ultrastructural
data help to elucidate phylogenetic relationships in the
Dothideomycetes?
Simon U.1, Bauer R.1, Groenewald J.2 and Crous P.2
1
Lehrstuhl Spezielle Botanik & Mykologie, Universität
Tübingen, Germany; 2Centraalbureau voor
Schimmelcultures, Utrecht, The Netherlands;
[email protected]
The Dothideomycetes (Ascomycota) include many
important plant pathogens. Although these fungi are of
great economic and scientific importance, many taxonomic
questions are still unresolved. By using the extraordinary
interaction between Cymadothea trifolii and its Trifolium
host plants as a starting point, we addressed the question if
ultrastructural characters could be used as markers for
phylogenetic relationships within the Dothideomycetes. In
conjunction we sequenced numerous members of this
group to construct a comprehensive phylogeny for
comparison of ultrastructural and genetic information. Here
we present observations of the cellular interaction of C.
trifolii
with
clover
including
results
from
immunocytochemical studies. These findings are compared
P23
with further plant-pathogen interactions occurring in the
Dothideomycetes and hitherto unpublished nuSSU, nuITS
and nuLSU rDNA sequence data for C. trifolii and other
Dothideomycetes. C. trifolii forms a complex interaction
apparatus in its own cells. Opposite this structure the host
plasmalemma produces a bubble. In an extremely small
area (ca 400 nm wide) between interaction apparatus and
bubble, the host cell wall is partially degraded: The pectin
matrix is dissolved, while cellulose and xyloglucan remain
intact. This type of interaction is unique among the
Ascomycota. Our genetic data place C. trifolii within the
Mycosphaerellaceae (Capnodiales). Additional obligate
biotrophic pathogens of the Mycosphaerellaceae will now
have to be studied to determine if similar interactions occur
elsewhere within the family.
P23: PLANT PHYLOGENY
P23: 1
A revised delineation of the grass tribe Aveneae and its
major groups (Poaceae)
Döring E., Schneider J. and Röser M.
MLU Halle, Germany; [email protected]
Increasing evidence from molecular and chromosomal
studies casts doubt on the previous circumscription of the
largest tribes recognized within grass subfamily Pooideae,
i.e., the Aveneae and Poeae which comprise some of the
world’s most important crop and pasture grasses (oat, false
oat, fescues, and bluegrass).
In contributing to a modern classification, the first 470 base
pairs from the chloroplast matK gene were studied in 140
samples across nearly all genera of the traditional Aveneae.
Additional genera from the tribes Poeae, Stipeae, Meliceae,
and Hainardieae were included for comparison and all
sequence data were evaluated for phylogenetic
reconstruction using Bayesian and parsimony-based
methods.
The resulting trees showed only one of the four subtribes
currently recognised within Aveneae, i.e., subtribe
Duthieinae as supported. It proved closer related, however,
with the feather grasses (Stipeae) instead of the Aveneae
and thus has to be excluded from the latter tribe. The other
subtribes of Aveneae, i.e., Aveninae, Alopecurinae and
Phalaridineae are not corroborated in their previous
circumscription but split into only two major clades. One of
it contains apart from some traditional Aveneae most of the
analysed Poeae as well as Milium (Stipeae) and Parapholis
(Hainardieae). The second contains exclusively members of
traditional Aveneae but additionally the genus Briza and its
relatives (Chascolytrum, Poidium).
P23: 2
Alternative ways of epigyny formation as criterion of
phylogeny of subfamilies Mesembryanthemoideae and
Ruschioideae (Aizoaceae)
Wowk M.
Lviv National Medical University, Ukraine;
[email protected]
Explored group of Mesembryanthemoideae and
Ruschioideae, which some scientists selects in separate
family, undoubtedly belongs to the most evolutionary
advanced subfamilies of Aizoaceae and represents the
monophyletic group (Bittrich, 1990). Reliable criterion for
determination of its phylogenetic position within the family
is flower structure, which peculiar high level of
evolutionary specialization. But, important differences exist
in their gynoecium structure, such as type of placentas
location. The Mesembryanthemoideae is presented by
central-angular placentation, and Ruschioideae – by basal
and parietal. In Ruschioideae variety of placentation types
is appropriate and caused by placentas displacement in
ontogenesis from central to basal-parietal position because
of receptacle invagination, which causes carpels
deformation. Ovary wall here is formed by receptacular
tissue. In Mesembryanthemoideae distinctions are caused
by another way of epigyny forming. As epigyny level is
low, receptacle is exposed only insignificant invagination
which doesn’t cause carpels deformation. Most probably
ovary wall in upper part is generated by sepals which
accrete with gynoecium. So, inferior ovary of receptacularappendicular nature is here formed. Anyway, on example
of these subfamilies we see two alternative ways of
epigyny forming, two ways of evolution which testifies that
Mesembryanthemoideae and Ruschioideae represent two
phylogenetic branches. Also, on the basis of epigyny level
it will be expedient to select within Ruschioideae the
genera groups exactly on type of placentation.
P23: 3
Ancestry of Mediterranean polyploid Helictotrichon
species (Poaceae)
Winterfeld G., Schneider J. and Röser M.
Institut of Biology Martin-Luther-University Halle,
Karyotypes of the Mediterranean species complex of
Helictotrichon bromoides (H. subg. Pratavenastrum) are
reported for widespread H. bromoides (2x), central
Mediterranean H. cincinnatum (4x), Ibero-Mauritanian H.
gervaisii subsp. arundanum (4x, 6x), and subsp. gervaisii
(8x), which is confined to a small area of southern Spain.
To clarify the ancestry of these polyploids with more or
less uniform chromosomal features, karyotype analysis was
carried out using chromosome banding with base pair
specific fluorescent dyes and fluorescence DNA in situ
hybridization. Three repetitive sequences, i.e. ribosomal
5S- and 45S rDNA and the subgenus-characteristic satellite
sequence COM2 were physically mapped on the
chromosomes to survey genomic re-arrangements.
Cytogenetic results and additional DNA sequence analyses
suggest that H. bromoides is one genome donor of
allotetraploid H. cincinnatum and allohexaploid H.
gervaisii subsp. arundanum, respectively. Further
genome(s) of the subsp. arundanum, characterised by large
subtelomeric bands of heterochromatin, are not known
from extant diploids until now. The autopolyploid subsp.
gervaisii is originated from this genome alone. The
cytogenetic data show that the polyploid evolution in this
species complex was accompanied by characteristic
chromosomal changes: (1) increase of chromosome length
variance, (2) decrease of symmetry, (3) increase of
heterochromatin, and (4) amplification of 5S rDNA repeats.
Reasons for the restriction of polyploids to comparatively
narrow geographical distributions are discussed.
POSTER ABSTRACTS
75
P23
P23: 4
P23: 6
Characterisation of the genus Lemna by amplified
fragment length polymorphism
Seebald E.1, Appenroth K.1, Baumbach H.2, Hellwig F.2,
Kühdorf K.1 and Schween U.1
1FSU Jena; Institute of Plant Physiology; 2FSU Jena;
Institut of Systematic Botany; [email protected]
Phylogenetic relationships among apple mosses
(Bartramiaceae)
Symmank L.1, Shaw B.2, Neinhuis C.1, Frahm J.3 and
Quandt D.1
1
Technische Universität Dresden, Germany; 2Duke
University, USA; 3Rheinische Friedrich-WilhelmsUniversität Bonn, Germany; [email protected]
Because of the low level of differentiation, the
identification of species of the former Lemnaceae family
(now assumed to be members of Araceae) on the basis of
morphological markers is a challenge even for experts.
Therefore, it is required to characterise species by
molecular markers. We have started a project using
amplified fragment length polymorphism (AFLP) applied
to all 13 known Lemna species. After application of four
primer combinations we obtained approximately 70 bands
for every plant species. These molecular markers are
sufficient to distinguish species of the genus and might be
extended to all 36 species of the duckweed subfamily.
Lemna minor is used for biomonitoring according to the
ISO protocol 20079. Clones of this species show different
sensitivity toward toxic heavy metals like Ag2+, Co2+, Hg2+,
Ni2+ and Tl+. Therefore, bar coding clones is necessary for
their characterisation and the identification of the clones
used. We investigated 69 different clones from all 13
species of the genus Lemna. All investigated clones could
be distinguished on the basis of the four primer
combinations and the obtained PCR products. Thus, AFLP
is a useful method to characterise clones of duckweeds.
P23: 5
Phylogenetic evaluation of the genus Masdevallia Ruiz
& Pav. (Orchidaceae) based on ITS nrDNA sequences
and morphological data
Abele A. and Rohwer J.
The genus Masdevallia comprises ~ 500 species distributed
from southern Mexico to southern Brazil. Species of
Masdevallia are characterized by callous petals and more or
less ligulate lips. Up to date no satisfactory classification
has been published, due to the homoplasy rife in
morphological features. The aims of this study are 1) to
address the infrageneric relationships using molecular data;
and 2) to find morphological synapomorphies for clades
well supported by molecular data.
Five of the 11 subgenera of Masdevallia form strongly
supported monophyletic groups in the analysis: subgenera
Cucullatia, Meleagris, Fissia, and the monospecific
Scabripes and Volvula. Subgenera Masdevallia, Pygmaeia
and Polyantha are polyphyletic. Subgenera Amanda and
Nidificia are not resolved in our data. Four major clades
were found. Clade A comprises subgenus Cucullatia, and
M. caudivolvula characterized by lateral sepals connate
beyond the middle. Clade B grouped subgenera Amanda,
Meleagris, and Nidificia; Dracula xenos, and M. picturata
characterized by the crested ovaries, and a lip divided into a
hypochile and an epichile. Clade C contains species of
subgenus Pygmaeia sections Amaluzae and Aphanes and
subgenus Masdevallia sections Durae and Masdevallia
characterized by peduncles with two or more internodes
and petals with a well-developed retrorse process from the
callus. Clade D contains species of subgenera Pygmaeia,
Masdevallia and Polyantha characterized by the tubular
imbricate floral bracts and the petals that are callous along
the labellar half.
76
POSTER ABSTRACTS
The worldwide distributed apple mosses (Bartramiaceae)
comprise one of the largest families among diplolepideousalternate mosses. According to recent studies the
Bartramiaceae are discussed to retain a position at the
transition from an acrocarpous to a pleurocarpus growth.
We provide the first comprehensive molecular phylogeny
based on the ITS 1&2 of nuclear ribosomal DNA (nrDNA)
and a plastid tRNA cluster, including 4 tRNAs (trnS, trnT,
trnL, trnF), a fast evolving gene (rps4), four spacers
separating the coding regions, as well as one group I intron.
With 73 accessions representing all 10 currently accepted
genera the sampling covers more than 10 % of the known
species diversity of the family. The phylogenetic analyses
support the recognition of the two recently established
genera Quathlamba and Flowersia, whereas Anacolia and
Bartramia are polyphyletic leading to two additional
genera. Fleischerobryum as well as Bartramidula should be
incorporated in Philonotis. Several sister group
relationships are strongly supported: Anacolia laevisphaera
and Batramia stricta; Quathlamba and Batramia s.
Vaginella; Anacolia s. str. and Flowersia; as well as a clade
comprising Conostomum, Philonotis and Breutelia.
Phylogenetic relationship of Plagiopus remains unresolved.
Although relationship between the genera could not be
resolved completely, our analyses reject the classification
by Griffin & Buck (1989) in three subfamilies.
P23: 7
Phylogenetic relationships within the CintiaSulcorebutia-Weingartia-complex
Ritz C.1, Löser C.1, Mecklenburg R.2 and Hellwig F.1
1
Institut of Systematic Botany, Germany; 2Langstedt,
Globular Andean cacti fascinate cactus breeders, because of
their great diversity and especially the remarkable
differences in flower colour. This great attention of
collectors resulted in a notoriously difficult taxonomy and
in an inflated numbers of synonyms. Previous studies
demonstrated that the rigorous lumping of many genera in
Rebutia s.l. is not supported by molecular data. The genera
Cintia, Sulcorebutia and Weingartia constitute a wellsupported monophyletic clade, which is clearly separated
from Rebutia s.s. This clade is well characterized by
hairless pericarpels with persistent auriculate scales as
opposed to the deciduous acute triangular scales
characteristic for Rebutia. We investigated the phylogenetic
relationships within the Cintia-Sulcorebutia-Weingartia
complex employing sequences of the trnS-trnG intergenic
spacer of the chloroplast DNA and data from AFLP
fingerprinting. Several morphological characters, e.g. the
adherence of the fruits, the shape of the areoles and the
branching of the funiculi are usually cited to distinguish
Sulcorebutia from Weingartia. However, transitions
between these characters are gradual. Molecular data do not
support the separation of Sulcorebutia and Weingartia but
the phylogeny reflects the geographic distribution of the
species.
P23
This analysis was initiated by the Studiengemeinschaft
Südamerikanische Kakteen e.V. (SSK) and partially
conducted within the “SSK Project 2006”. The latter
project was financially sponsored by the Freistaat
Thüringen, Germany."
P23: 8
Phylogenetic studies in the Persea group (Lauraceae)
Rohwer J.1, Li J.2, Rudolph B.1, Schmidt S.1 and Li H.2
1
Biozentrum Klein Flottbek, Univ. Hamburg, Germany;
2
Xishuangbanna Tropical Botanical Garden, Kunming,
China; [email protected]
The Persea group is a monophyletic group within the
Lauraceae, consisting of seven currently recognized genera,
with an estimated 400 to 450 species. Among them is the
economically most important species of the Lauraceae, the
avocado (Persea americana). About 90 species of the
group occur in (warm-temperate to) tropical America, and
two in the Macaronesian islands, while the majority is
found in warm-temperate to tropical Asia. The delimitation
of the genera against one another has always been
controversial, and nearly all of them have been included in
Persea by some author at some time. Therefore, the aim of
our study was to elucidate the phylogenetic lineages within
this group. Among numerous molecular markers tried,
only the nuclear ribosomal internal transcribed spacer (ITS)
provided significant resolution. Preliminary results, based
on 44 samples, indicate that the Asian genus Machilus and
the subgenus Eriodaphne of the almost exclusively
American genus Persea (s.str.) are well defined
monophyletic groups, and that the Macaronesian Persea
indica is a member of the Eriodaphne clade. Persea
americana and P. schiedeana (= subgen. Persea) form a
clade separate from the other species of Persea. All of the
other genera of which more than a single species has been
investigated appear to be polyphyletic. The whole group is
strongly in need of revision.
P23: 9
Phylogeography of Aristolochia (Aristolochiaceae) in
Africa and the Mediterranean
Neinhuis C., Mahfoud H. and Wanke S.
Technische Universität Dresden, Germany;
[email protected]
We provide evidence for a complex phylogenetic and
biogeographic pattern of the genus Aristolochia in Africa
and the Mediterranean. Subgenus Pararistolochia is
confined to tropical rain forests and forms a clade together
with species from Asia. Subsection Podanthemum most
probably colonised Africa two times independently, once
by Aristolochia albida and once by Aristolochia
bracteolata. Within the Mediterranean, Near East and
Caucasian species of subsection Aristolochia two
morphologically and biogeographically well supported
clades can be identified: the Near East/Caucasian species
and the West Mediterranean species which presumably
show a rapid morphological radiation in the Near East (or
close to this area) with a subsequent star like colonisation
of the different current distribution areas. This
morphological differentiation, however, is not paralleled on
the molecular level. Phylogenetic tree reconstruction
provides virtually no support for the relationships between
clades, while most clades as such are highly supported as
monophyletic. Northern Africa is inhabited by
Mediterranean species from subsection Aristolochia.
Interestingly A. pistolochia from the west Mediterranean
and A. clematitis a temperate Eurasian species, are not
clustering with one of the main clades, but represent
independent lineages as A. baetica and A. sempervirens do.
I addition, A. rigida, an endemic from Somalia, is wellsupported sister to the subsection Aristolochia. The
previous groupings for the latter, based on morphological
characters, need to be revised based upon our results.
P23: 10
Polyphyly of the small Holarctic grass tribe
Hainardieae
Schneider J., Döring E. and Röser M.
Martin Luther University of Halle-Wittenberg, Germany;
[email protected]
Hainardieae are a small tribe the grass subfamily Pooideae
with only six genera and approximately 10 species.
Morphologically, the tribe seems clearly characterised by
spicate inflorescences and spikelets arranged in two rows.
The species are mostly annuals adapted to moist saline soils
and distributed in the western North America (Scribneria)
and the Mediterranean to Central Asia (Agropyropsis,
Hainardia, Narduroides, Parapholis, Pholiurus). The
relationship among the six genera was studied using
sequence variation of the internal transcribed spacer (ITS)
of nuclear ribosomal DNA and chloroplast matK sequence
data. Additionally, many genera of the Aveneae and Poeae
were included for comparison. Both datasets revealed the
Hainardieae as highly polyphyletic and its genera clustering
with different lineages of Aveneae/Poeae. Obviously, the
unbranched inflorescences of ‘Hainardieae’ have originated
several times in parallel within the Aveneae/Poeae and are
not indicative of phylogenetic relatedness. A maintenance
of tribe Hainardieae thus is not supported.
P23: 11
Rapidly evolving DNA unravels the branching order
among basal Eudicots
Barniske A.1, Borsch T.2, Worberg A.2, Müller K.2 and
Quandt D.1
1
Technische Universität Dresden, Germany; 2Rheinische
Friedrich-Wilhelms-Universität Bonn; [email protected]
Analyses of non-coding and rapidly evolving DNA from
the chloroplast genome's single copy regions (trnL-F, petD
intron, matK) has recently yielded well supported
phylogenetic hypotheses for basal eudicots, with
Ranunculales as first branching lineage, followed by
Sabiales, Proteales, Trochodendrales, Buxales and the core
eudicots. Under parsimony, high resolution and statistical
support was obtained for all deep nodes of the basal eudicot
grade. In model based approaches, the position of Sabiales
was lacking support, however. By adding and analysing
further sequence data from two more group II introns
(rpL16, trnK) as well as the atpB-rbcL spacer an enhanced
phylogenetic signal finally resolves the position of Sabiales
among basal eudicots.
It appears that the combined analysis of sequence data from
rapidly evolving and non-coding genomic regions leads to
significantly improved statistical support values on all
levels in comparison to earlier studies of basal eudicots
using multiple conserved genes. As this is attributed to
different underlying evolutionary constrains within noncoding regions, we performed partitioned analyses
considering functional and structural aspects, in order to
POSTER ABSTRACTS
77
P23/P24
trace e.g. the contributions of core versus peripherical
intron elements or helical versus loop structures etc.
P23: 12
The ITS2 Database – Boosting Phylogenetics
Wolf M., Philippi N., Seibel P., Selig C., Dandekar T.,
Müller T. and Schultz J.
University of Würzburg, Germany;
[email protected]
The internal transcribed spacer 2 (ITS2) is a widely used
phylogenetic marker. Its applicability was enhanced with
the discovery that in addition to its highly variable
sequence it contains a conserved structural core. To aid
analyses considering both, sequence and structure, we have
developed the ITS2 Database. The second release contains
more than 65.000 structures following the previously
published hallmarks. The WEB interface was completely
redesigned to allow faster and more intuitive interactions.
Additional features like the prediction of partial structures
and homology modelling of user supplied RNA sequences
have been added.
Using this increased dataset we were able to test the
hypothesis that a compensatory base change (CBC) in the
ITS2 is an indicator distinguishing species. When a CBC
was found between two organisms classified within the
same genus, in 93% they belong to different species. Thus,
a CBC in an ITS2 sequence-structure alignment is a
sufficient criterion to distinguish even closely related
species. This example illustrates how the ITS2 Database
together with 4SALE (a tool for synchronous RNA
sequence and secondary structure alignment and editing)
can boost phylogenetic analyses.
Availability:
ITS2 Database: http://its2.bioapps.biozentrum.uniwuerzburg.de
4SALE http://4sale.bioapps.biozentrum.uni-wuerzburg.de
P23: 13
The Problem with Generic Limits - An Example from
the Danthonioid Grasses
Humphreys A.1, Pirie M.1, Verboom G.2 and Linder H.1
1
Institute for Systematic Botany, University of Zürich,
Switzerland; 2Bolus Herbarium, University of Cape Town,
South Africa; [email protected]
Systematic biology is in an age of reciprocal illumination,
where new insights from molecular data allow
reassessment of traditionally recognised taxonomic groups.
At the generic rank there seems to be a discrepancy
between genera recognised by classical taxonomic
measures and monophyletic groups identified by molecular
phylogenetics. Rytidosperma s. l. (Danthonioideae:
Poaceae) comprises ca. 100 species on all southern
hemisphere continents, in seven currently recognised
genera: three in Africa and four in Australasia, one of
which extends to South America. Much controversy has
plagued circumscription of and relationships between
genera in the group ever since Danthonia was described for
grasses with twisted column bases over two centuries ago.
We present the first molecular phylogeny of Rytidosperma
s.l. from all continents. We show that the African species
are sister to the Australasian and South American species,
that none of the genera as currently delimited is
monophyletic and that Australian lowland species are
distinct from their American equivalents in the genus
Danthonia. This poses the question: What constitutes a
nomenclaturally stable genus? Genera do not occur in
78
POSTER ABSTRACTS
nature, but are defined by us in order to ease
communication. Since the genus epithet is part of the Latin
binomial used to name species, generic (re)delimitation
may be of considerable practical consequence for many
users, both scientific and non-scientific. We discuss
whether nomenclaturally stable genera that are both
monophyletic and diagnosable using morphological
characters can be found.
P24: FLORAL DIVERSITY
P24: 1
Determination of the apical meristem in racemous
inflorescences
Bull-Hereñu K. and Claßen-Bockhoff R.
Johannes Gutenberg Universität, Germany; [email protected]
Truncation, i.e. the loss of the terminal flower in
inflorescences, is usually interpreted as a derived condition.
However, no developmental or ecological constraints are
known that force truncation. In a comparative
developmental study we test the hypothesis that physical
attributes determine the absence or presence of a terminal
flower. We investigated racemes (simplest inflorescences
without terminal flower) and botryoids (simplest
inflorescences with terminal flower) in 17 species of 9
families of the Eudicots and added data from further 14
species form the literature. Our results show that, first, in
the transition from the vegetative to the reproductive stage,
the apical meristem (AM) enlarges and changes its shape,
that second, no terminal flower appears in inflorescences
with eight or more parastichies and that third, the diameter
of the AM is generally larger in botryoids than in racemes
of the same parastichy number. We further noticed that
proliferating racemes, that continue growth after flower
production, show no change at the AM at all. We conclude
that physical conditions at the AM of developing
inflorescences, such as size-shape relations, contribute in
determining a terminal flower. Our results further show that
proliferating inflorescences in fact represent vegetative
shoots whose axillary meristems become reproductively
stimulated in contrast to the true inflorescences (with
limited growth) that originate from reproductively changed
AMs.
P24: 2
Diversity, development and evolution of asymmetric
flowers in Senna (Leguminosae)
Marazzi B. and Endress P.
Institute of Systematic Botany, University of Zurich,
Switzerland; [email protected]
The buzz-pollinated genus Senna (Leguminosae) includes
both species with monosymmetric and diverse asymmetric,
enantiomorphic (enantiostylous) flowers, with left and right
morphs on the same plant. To assess homology of the floral
asymmetry patterns, we studied flower structure of species
from all major clades of Senna, and development of four
enantiomorphic species. The asymmetry morph of a flower
is correlated with the direction of spiral calyx aestivation
(clockwise: right morph; counter-clockwise: left morph).
We recognized five major patterns of floral asymmetry,
resulting from different combinations of at least six
structural elements: (1) deflection of the carpel; (2)
deflection of the median abaxial stamens; (3) deflection of
one lateral abaxial stamen or, rarely, (4) modification in
P25
size of this stamen; and modification in shape and size of
(5) one or (6) both lower petals. Expression of floral
asymmetry during development differs among floral
whorls. Corolla asymmetry begins in early bud (unequal
development of lower petals), androecium asymmetry in
mid-stage bud (unequal development of thecae in median
abaxial stamen; twisting of androecium) or at anthesis
(stamen deflection), gynoecium asymmetry in early bud
(primordium appearing off the median plane; ventral slit
laterally oriented) or mid-stage to late bud (carpel
deflection). Ancestral character state reconstructions
moderately support the hypothesis that the carpel was not
deflected in ancestral Senna flowers, but strongly support
that asymmetric androecium and corolla evolved from
enantiostylous flowers.
P25: PLANT-ANIMAL
INTERACTION
P25: 1
Evolution of Insect Defense Strategy of Leaf Beetles
(Chrysomelina) that use Herbal Precursors
Michalski C.1, Mohagheghi H.2 and Ober D.1
1
Botanisches Institut, Kiel, Germany; 2Institut für
Phamazeutische Biologie, Braunschweig, Germany;
[email protected]
Larvae of chrysomelid leave beetles use different chemical
defense strategies. Salicylaldehyde and chrysomelidal are
two frequent defensive compounds found in glandular
secretions. The biosynthesis of salicylaldehyde and
chrysomelidial is studied in Chrysomela tremulae and
Phaedon cochleariae. While Phaedon cochleariae is able
to produce chrysomelidial autogenously, Chrysomela
tremulae needs to uptake salicin as an herbal precursor for
salicylaldehyde biosynthesis from cottonwoods. Both
transformations require two successive enzymes: a βglucosidase and an oxidase. The similarity between these
pathways suggests that both defense strategies have a
common origin in evolution. To identify cDNA sequences
that encode the mentioned enzymes, mRNA is extracted
from insect larvae, transcribed into cDNA and amplified by
PCR with degenerate primers designed according to partial
protein sequences. The expression in E. coli cells resulted
in formation of inclusion bodies. To yield soluble and
active enzymes for biochemical characterization further
expression systems (e.g. K. lactis) will be tested.
Recombinant enzymes will be purified by affinity
chromatography and assayed by GC analysis.
P25: 2
Interaction of poplar extrafloral nectaries and honey
bees
Escalante Pérez M.1, Fromm j.2, Hedrich R.1 and Ache
P.1
1
universität wuerzburg, Germany; 2Technical University
Munich, Germany; [email protected]
Several plants, among them poplar species, use secretoric
organs to attract insects. In contrast to floral nectaries the
function of so-called extrafloral nectarines is to protect the
plant from pests by attraction of herbivore predators.
Honey bees do not fulfill this bodyguard function, but it is
known, that by visiting the nectaries they have an impact
on the quality and quantity of nectar production and thus on
attraction of wanted visitors. Up to now it has not known,
how, on the molecular level, nectar production is induced.
Our studies focus on this topic by asking: Which events
induce the nectar production? How are these processes
regulated? How do bee’s visits change nectar quantity and
quality? To answer these questions we started to examine
the morphology and physiology of the nectaries. We
analyzed ultrastructure of the nectar producing cells,
production, composition and allocation of nectar
metabolites like sugars, amino acids and antimicrobial
substances. We simulated herbivory events by wounding
and found a correlation to nectary appearance. After 24
hours, nectarines were also visible on non-treated leaves,
pointing to a systemic response towards herbivores. We
currently study stimulus induced changes of nectary
expression pattern. First microarray analyses of nectaries
will be presented.
P25: 3
Investigating potential benefits of iridoid glycoside
sequestration in Longitarsus melanocephalus
(Coleoptera, Chrysomelidae)
Baden C. and Dobler S.
Whenever noxious plant compounds are taken up and
recycled by insects, a protective function of these
sequestered compounds is assumed. The flea beetle
Longitarsus melanocephalus sequesters iridoid glycosides
from its host plant up to a concentration of 2 % DW, yet so
far it remained unknown whether the insects actually gain
protection from the plant compounds at these
comparatively low concentrations. We here tested for
various soil and litter living potential enemies and
pathogens whether iridoid glycosides may deter or inhibit
them. In choice experiments presenting L. melanocephalus
together with Tribolium castaneum pupae, the predators
Lithobius forficatus (Lithobiidae) and Forficula auricularia
(Forficulidae) as well as the nematode Heterorhabditis
bacteriophora (Heterorhabditae) were not deterred by the
iridoid glycoside containing pupae. However, L. forficatus
avoided artificial baits doted with 2 % iridoid glycosides
while F. auricularia showed no aversion to it at these
concentrations and H. bacteriophora did not suffer any
toxic effect. Of the pathogens tested, the entomopathogenic
fungi Beauveria bassiana and Metarhizium anisopliae
(Deuteromycetes) were not inhibited in their growth by
iridoid glycosides ranging up to 2 %. However, an
inhibitory effect could be observed against the
entomopathogenic bacterium Bacillus thuringiensis, even at
this relativly small concentration. Since B. thuringiensis
might be just one bacteria that could be noxious to L.
melanocephalus, the antimicrobial effect might thus be the
true selective value of the sequestration.
P25: 4
Local and systemic effects of spider mite and caterpillar
herbivory on leaf growth and amino acid concentrations
in cotton leaves
Schmidt L., Schurr U. and Röse U.
Institute Phytosphere, Research Centre Jülich, Germany;
[email protected]
Cotton plants have to cope with a broad range of herbivores
with different feeding habits. Spider mites pierce individual
plant cells and removing the contents while Lepidoptera
larvae consume larger amounts of leaf tissue. The aim of
this study was to investigate the physiological local and
POSTER ABSTRACTS
79
P25
systemic effects of spider mites infestation over five days
and to compare it to damage caused by caterpillar feeding.
Cotton plants with two fully grown leaves were chosen and
herbivores were placed on a fully expanded leaf that was
still growing. The leaf above the treated leaf was
investigated for systemic effects of herbivory. We found
that infestation with spider mites on a single leaf did neither
affect the relative growth rates of leaves locally nor
systemically. In contrast, caterpillar feeding significantly
reduced the relative growth rate of the leaves locally but
not systemically. Analyses of free amino acids in the leaves
showed no significant differences in plants infested with
mites on a single leaf compared to non-infested plants.
Caterpillars had a more pronounced effect on the amino
acid profile of cotton plants. Phenylalanine, a precursor of
salicylic acid and phytoalexins, was reduced locally while
tryptophan, a degradation product of indole, was strongly
increased in these leaves. The concentrations of
methionine, a precursor of ethylene remained at levels of
control plants. It can be concluded that leaf growth and free
amino acids composition in cotton plants are not affected
by infestation of spider mites but are affected by caterpillar
feeding on one single leaf.
P25: 5
Molecular characterization of an acidic endochitinase
from Nepenthes rafflesiana
Rottloff S.1, Stieber R.1, Piotrowski M.2 and Mithoefer
A.1
1
Max-Planck-Institute for Chemical Economy, Germany;
2
Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität
Carnivorous plants are able to capture and digest
arthropods, and thereby to increase their supply of
nutrients, particularly of nitrogen. Plants of the genus
Nepenthes produce pitchers, which are highly specialized
trapping organs that serve the attraction, capture, and
digestion of the prey. Glands, located on the inner surface
of the digestive zone, are responsible for the production and
secretion of the pitcher fluid, in which insects are digested
by hydrolytic enzymes. In the literature, basic chitinases
have been reported to be involved in this process, as shown
for Nepenthes khasiana.
Based on proteomic analyses of the fluid from closed
pitchers of different species, several peptides were found
that could be assigned to previously characterized digestive
enzymes, and a peptide of an acidic chitinase. Using the
peptide sequence of the latter, the full-length cDNA
sequence for Nepenthes rafflesiana was determined by a
polymerase chain reaction (PCR) with degenerative primers
followed by RACE- and Pfu-PCR. The corresponding
enzyme has a calculated isoelectric point of four and a
molecular weight of 31 kDa, which is in accordance with
the results of 2D gel electrophoresis.
For further proof heterologous expression of the enzyme
was achieved in E. coli, using co-expression of chaperones.
Photometric and fluorimetric assays were applied to further
characterize the enzymatic properties of the protein.
P25: 6
Moose - a driving force in shaping patterns of plant
response and plant- and plant consumer-communities
Stolter C.
University of Hamburg, Biozentrum Grindel, Germany;
[email protected]
80
POSTER ABSTRACTS
The intra-individual plant response of Salix phylicifolia due
to moose browsing might result in different effects for the
willow itself and associated plant consumers (e.g.
herbivorous insects and pollinators). Morphological and
detailed chemical analyses concerning secondary plant
chemistry were conducted to investigate differences in
plant response within an individual plant. Moose browsing
in winter results in two different types of twigs (new annual
shoots) on the willow Salix phylicifolia in the subsequent
spring. New growth of browsed and unbrowsed twigs on
the same individual willow differed in morphology and
chemical composition (intra-individual response). New
growth (leaves) from browsed twigs had higher
concentrations of some individual phenolics, a higher
biomass and lower concentrations of nitrogen than the new
growth of unbrowsed twigs. This constellation should have
an influence on subsequent consumers like leaf beetles.
However, I found no differences in the feeding behavior of
herbivorous insects on the leaves growing on the new
annual shoots of either browsed or unbrowsed twigs. The
results from a field study were confirmed by a bioassay,
using the generalist leaf beetle Gonioctena pallida. The
new annual shoots (twigs) of unbrowsed twigs, which were
protected by different specific phenolics, had more catkins
than the new growth of browsed twigs. Hence, browsing
has an impact on willow reproduction and pollinators.
Consequently, large herbivores like moose might be a
driving force in shaping patterns of plant response and
plant- and consumer- communities.
P25: 7
Testing for cardenolide resistance in the Oleander
Hawk-moth (Daphnis nerii)
Petschenka G. and Dobler S.
Universität Hamburg, Germany;
[email protected]
Cardenolides (a special type of cardiac glycosides) possess
a highly specific mode of action as they inhibit the Na+K+ATPase which is a ubiquitous enzyme throughout the
animal kingdom.
Insects feeding on cardenolide containing plants are
expected to have some specific adaptations to avoid a toxic
effect of the plant compounds. These adaptations could
range from impermeable guts to highly efficient excretion
processes which protect the Na+K+-ATPase from the
toxins. However, one successful strategy to cope with
cardenolides is to decrease the susceptibility of the enzyme
to the compounds.
Molecular changes that prevent a binding of cardenolides to
the Na+K+-ATPase have been described in the Monarch
butterfly1 (Danaus plexippus) and several other insects on
cardenolide containing plants2,3. We here investigate the
sensitivity of the Oleander Hawk- moth, Daphnis nerii, a
species specialised on the cardenolide plant, Nerium
oleander. It is already known that the caterpillars of D.
nerii sequester cardenolides which they ingest with their
diet4. It is further known that the Na+K+-ATPase of this
species lacks the insensitivity conferring mutation
described for the Monarch5. To test whether the Na+K+ATPase of D. nerii might nevertheless be insensitive to
cardenolides we use a physiological assay in our study that
measures in vitro the ATP conversion by quantifying the
release of inorganic phosphate in dependence of varying
ouabain concentrations.
1: Holzinger&Wink 1992; 2: Labeyrie&Dobler 2004
3: Göttling et al. this volume; 4: Abe et al. 1996;
5: Mebs et al. 2000
P25/P26
P25: 8
The influence of green leaf herbivory on floral VOC
production and emission of Nicotiana suaveolens
Effmert U., Dinse C. and Piechulla B.
University of Rostock, Institute of Biosciences,
Biochemistry, Germany; [email protected]
A vast variety of comprehensive investigations have
focussed on the phenomenon of damage-induced
production and emission of volatile organic compounds
(VOCs) by herbivore-infested green leaves of plants. An
additional interesting question would be if and how flowers
directly respond to herbivore attack on leaves. To answer
this question, the production and emission of floral VOCs
of uninfested and Manduca sexta larvae infested Nicotiana
suaveolens plants were monitored with particular focus on
the floral VOC methyl benzoate. As a result, it could be
demonstrated that the amount of methyl benzoate emitted
as well as the emission pattern were not significantly
altered in comparison to the uninfested control. Methyl
benzoate and other main scent components like benzyl
benzoate, benzyl salicylate, benzyl alcohol, phenylethyl
alcohol, indole, and cinnamic derivatives were nocturnally
emitted. The ratio of the components within the floral VOC
mixture stayed the same. The mRNA level, protein level,
and enzyme activity of the benzoic/salicylic acid
methyltransferase, which is responsible for O-methylation
of benzoic acid did also not change in the progression of
larval damage in comparison to the control. These results
suggest that herbivory on vegetative organs does not
directly provoke an alteration of floral VOC synthesis and
emission. This seems to be a rather autonomous process.
P26: PLANT-MICROBE
SYMBIOSIS
P26: 1
Analysis of an atypical receptor protein and of auxin in
the beneficial interaction between the endophytic
fungus Piriformospora indica and Arabidopsis thaliana
Wehner P.1, Ritter C.1, Ludwig-Müller J.2, Shahollari
B.1 and Oelmüller R.1
1
FSU Jena, Germany, Institute of Gerneral Botany and
Plant Physiology; 2TU Dresden, Institute for Botany, 01062
Dresden; [email protected]
The endophytic fungus P. indica promotes growth and seed
production of A. thaliana.
We aim to study this beneficial plant-microbe interaction
on molecular level by analysing the role of (1) auxin and
(2) an atypical receptor kinase.
(1) Under our standardized growth conditions, the auxin
levels in roots were not changed and auxin-response
promoters were not upregulated in the presence of the
fungus although plants were bigger. Selective k.o. lines in
auxin biosynthesis/metabolism did not affect the growth
response to the fungus. However, an auxin overproducer
responded more sensitive to the fungus. Conclusively,
auxin plays only a minor role in the beneficial interaction
between the two symbiotic partners.
(2) During the recognition period of both organisms, the
message for a receptor kinase with leucine-rich repeats
(LRR1) is transiently upregulated. LRR1 is an atypical
receptor kinase because three highly conserved amino acids
required for kinase activity are replaced. The kinase is
located in Triton X-100-insoluble plasma membrane
microdomains.
The role of LRR1 in early steps of the beneficial interaction
between the two symbiotic partners is studied. We want to
identify components which link the atypical receptor kinase
to downstream signalling events. This includes the
identification of putative interaction partners by two-hybrid
screens, the characterization of candidate proteins in vitro,
and confirmation of their essential roles for the interaction
in vivo.
P26: 2
Apocarotenoids: Physiologically relevant compounds
for the AM symbiosis or waste products?
Floß D., Strack D. and Walter M.
Leibniz Institute of Plant Biochemistry, Germany;
[email protected]
During the arbuscular mycorrhizal (AM) symbiosis plant
roots frequently accumulate carotenoid cleavage products
leading to a yellow or orange-brownish coloration known
as “yellow pigment”. A linear C14 apocarotenoid, termed
mycorradicin, was identified as the chromophore of this
pigment. Concomitantly plant roots accumulate other
apocarotenoids, which are colorless C13 cyclohexenone
derivatives. A functional significance of these
apocarotenoids for the AM symbiosis is still unknown. For
the elucidation of this function we successfully suppressed
the biosynthesis of apocarotenoids in Medicago truncatula
with an RNAi approach of the mycorrhiza-responsive 1deoxy-D-xylulose 5-phosphate synthase2 (DXS2). DXS
catalyzes the first step of the plastidial MEP (2-C-methyl-derythritol 4-phosphate) pathway producing the precursors
IPP and DMAPP for the biosynthesis of isoprenoids
including apocarotenoids. In roots with strongly silenced
MtDXS2 transcripts a reduction in the transcript levels of
the AM-specific phosphate transporter MtPT4 was
observed along with an increase in degenerating and dead
arbuscules. However, roots with a minor silencing of
MtDXS2 surprisingly revealed a marked increase in MtPT4
transcript levels indicating changes in the physiology of the
arbuscule-harboring cells. These conflicting results reveal
that not only apocarotenoid biosynthesis appears to be
affected by the RNAi approach and that different MEP
pathway-derived products may have different roles for the
functionality of arbuscules.
P26: 3
Ectomycorrhizal gene expression in heavy metal stress
response
Kothe E., Krause K., Schlunk I., Asiimwe T., Ghergel F.
and Formann S.
Friedrich-Schiller-Universität Jena, Germany;
[email protected]
The ectomycorrhizal fungus Tricholoma vaccinum shows
host specific gene expression in association with the
compatible host spruce (Picea abies) as compared to a low
compatibility interaction. Using an in vitro model system,
differential gene expression analysis identified a MATE
(multidrug and toxic compound extrusion) transporter gene,
mate, which is investigated by overexpression in T.
vaccinum to identify the substrate specificity of the encode
protein. A second gene induced in mycorrhiza is the
aldehyde dehydrogenase gene adh1 which is inducible with
either ethanol or indole-3-acetaldehyde and therefore can
be assumed to be involved in plant interaction via hormone
POSTER ABSTRACTS
81
P26
release. Fungal cultures induced with indole-3acetaldehyde show hyperbranching hyphae which are a
reminescent of the heavy branching observed in the fungal
mantle tissue of mycorrhiza and the Hartig’net where
nutrient exchange in the mutual symbiosis takes place. A
microarray sceening system is developed to show heavy
metal stress response in heavy metal contaminated soil.
This work is linked to the investigation of oak (Quercus
robur) trees grown on heavy metal containing soil resulting
from uranium mining in Eastern Thuringia. The
biodiversity and linkage of early and late stage mycorrhizal
fungi, the fungal community structure, and multivariate
factor analyses were used to define the ectomycorrhizal
fungi communities.
P26: 4
Hydroponics with diffusive oxygen supply
Pörs Y. and Ehwald R.
Humboldt-Universität zu Berlin, Germany;
[email protected]
Aeration of axenically grown roots in hydroponics requires
investment and efforts. A new simple aeration technique
suitable for growing axenic root systems was developed on
the basis of diffusive oxygen supply. The culture vessel
contains a module of gas-filled non-wettable porous
polypropylene
microfibers
developed
for
blood
oxygenation (Accurel®, Membrana, Düsseldorf). The
oxygen partial pressure is kept close to saturation by
diffusive oxygen supply. Roots develop under more natural
conditions with respect to carbon dioxide/bicarbonate
concentrations
than
in
convectionally
aerated
hydrocultures. Since the fiber membrane is unpermeable to
microbes (pore size 0.2 µm) the aeration method is well
suitable to obtain axenic root systems or root systems
growing in combination with defined microbic partners.
P26: 5
Identification of specific transcription factors involved
in the beneficial plant/fungus interaction between
Piriformospora indica and Arabidopsis thaliana
Camehl I. and Oelmüller R.
Friedrich Schiller Universität Jena, Germany;
[email protected]
The majority of studies on beneficial plant-microbe
interactions are focused on the symbiosis of plants with
rhizobia and arbuscular mycorrizal fungi. The recently
discovered endophytic fungus of the Sebacinaceae family,
Piriformospora indica, promotes plant growth and seed
production. The fungus is able to associate with the roots of
various plant species, including A. thaliana, in a manner
similar to arbuscular mycorrhizal fungi. While mycorrizal
fungi are obligate biotrophs, P. indica can be easily
cultured in axenic cultures. We investigate the interaction
between P. indica and the model plant A. thaliana.
Stimulation of enzymes in nitrate and starch metabolism
might be crucial for the growth promotion, mediated by the
fungus. The transcript levels of the Arabidopsis nitrate
reductase (Nia2) and the starch-degrading enzyme glucan
water-dikinase (SEX1) are upregulated after co-cultivation
with P. indica. Promoters of Nia2 and SEX1 are probably
activated by a transcription factor complex. Using mass
spectrometry the homeodomain transcription factor BLH1
was determined within this complex (Sherameti et al 2005,
JBC 280, 2641-2647). Insertional mutagenesis in BLH1
82
POSTER ABSTRACTS
prevented the growth promoting effect induced by P.
indica.
BLH1 belongs to the TALE protein family, which contains
regulators of plant meristem and leaf development. This
protein forms also homo- and heterodimers with members
of the TALE homeodomain and ovate protein families
(Hackbusch et al 2005, PNAS 102, 4908-4912). This work
aims to clarify the role of the transcription factor complex
in this interaction.
P26: 6
Localization of acid invertases in ectomycorrhizal roots
Kulmann C.1, Bücking H.2 and Heyser W.1
1
University of Bremen, Germany; 2Rutgers, State
University of New Jersey, USA;
[email protected]
Acid invertases, catalyzing the conversion of sucrose to
hexoses, are key enzymes of plant carbohydrate
metabolism and they are required for the efficient
distribution of sugars from source to sink tissue. A strong
carbohydrate sink is the ectomycorhizal symbiosis,
sometimes consuming up to 30% of the net photosynthetic
carbohydrate production. Most ectomycorrhizal fungi are
unable to use sucrose directly as a carbon source and
require its prior conversion into hexoses. Plant invertases
are required for this conversion, as ectomycorrhizal fungi
do not possess such enzymes on their own. From previous
studies it is suspected that sucrose is released into the
apoplasmic interface between plant and fungus and then
cleaved by a plant cell wall acid invertase, thus making the
carbohydrates available to the fungal partner. Using a
peptide derived from a highly conserved domain of plant
cell wall invertases, we have produced an antiserum and
affinity-purified antibody specific for cell-wall invertases.
In histological sections of a poplar ectomycorhizal
association, these antisera indicate the presence of cell wall
invertases at the apoplastic interface. In this example,
invertases are accumulated at the cell wall boundary
between the rhizodermis and the first cortical cell line. This
zone is penetrated by flat fungal hyphae and is probably a
zone of active metabolism and nutrient exchange in both
organisms. Our results suggest that sucrose is cleaved
apoplasmically at the innermost contact surface of plant
and fungus, but glucose and fructose may be available
throughout the whole interface.
P26: 8
MATH proteins involved in the interaction between
Piriformospora indica and Arabidopsis thaliana
Drzewiecki C. and Oelmüller R.
Friedrich-Schiller-Universität Jena, Germany;
[email protected]
The Basidiomycete Piriformospora indica interacts with
Arabidopsis roots in a fashion similar to arbuscular
mykorhizza. One of the earliest events is a transient
modification of the MATH (meprin and TRAF (tumour
necrosis factor receptor associated factor) homology) 1
protein (Peskan et al. 2004) in the plasma membranes of
Arabidopsis roots. 59 MATH proteins are present in the
Arabidopsis genome. Phylogenetic analysis uncovered that
MATH 1 is closely related to MATH2 and 3.While the
expression level for MATH 1 is high in Arabidopsis roots,
those of MATH 2 and 3 are much lower. Inactivation of
MATH 1 by insertional mutagenesis uncovered that this
protein is essential for plant development, and results in
embryo lethality. Thus, the role of MATH 1 for this
P26
beneficial interaction could not be analysed. Deletion of
MATH 2 and 3 did not cause an obvious phenotype.
Expression analysis of the three MATH genes grown in the
absence or presence of P. indica uncovered that they have
distinct functions. Both MATH 2 and 3 are involved in
beneficial interaction. The role of these MATH proteins for
Arabidopsis root development and the interaction with P.
indica will be discussed.
P26: 9
Mycorrhizal progression in Polygalaceae
Rath M., Imhof S., Weber H. and Phoris C.
Philipps-Universität Marburg FB Biologie Spezielle
Botanik und Mykologie Ab; [email protected]
Publications on the mycorrhiza of Polygalacea are scarce
and date back about 100 years, except for one recent article
(Plant Biology, in press) on the achlorophyllous genus
Epirixanthes. However, these works showed signs for a
specific colonization pattern of Paris-type arbuscular
mycorrhiza. Hence, we examined 11 Polygala spp., shrubs,
perennial and annual herbs from North Amerika, Afrika
(green house material) and Europe, in order to test the
hypothesis of a structural specificity and iterative
progression of mycorrhizal colonization pattern.
All species investigated showed the same basic intracellular
mycorrhizal pattern, colonizing the outer cortex without
significant longitudinal spread heading for the penultimate
layer of the cortex parenchyma. Only in this layer the
hyphae spread longitudinally and tangentially. From there
the anatomically distinct innermost parenchyma layer
becomes penetrated. Degeneration of hyphae mainly occurs
within the latter layer.
Variations of this pattern concern the mode of hyphal
growth in the different layers (straight or coiled) and the
formation of arbuscules, arbusculate coils or coils in the
innermost parenchyma layer. These variations can be
arrayed in order to describe a hypothetical evolutionary
progression of mycorrhizal pattern, resulting in improved
benefit from the fungus, which finally enabled a group of
species (Epirixanthes spp.) to omit photosynthesis.
P26: 10
Soil streptomycete - mediated induction of disease
resistance in Norway spruce and Arabidopsis thaliana
Schrey S.1, Tarkka M.2, Lehr N.1, von Rad U.3 and
Hampp R.1
1
University of Tuebingen, Germany; 2UFZ - HelmholtzCentre for Environmental Research, Halle, Germany; 3GSF
- National Research Centre for Environment and Health,
Oberschleißheim; [email protected]
The release of organic compounds from plant roots into the
rhizosphere forms the basis for a versatile community of
microorganisms that may influence productivity and
resistance against diseases. Inoculation of Norway spruce
(Picea abies) roots with the forest soil bacterium
Streptomyces sp. GB 4-2 (GB 4-2) hinders colonisation of
inner root tissues with the pathogenic fungus
Heterobasidion abietinum through the induction of cell
wall appositions in the inner cortical cell layers, increased
xylem formation in the vascular cylinder and increased
peroxidase activity after bacterium-fungus co-inoculation.
Following root inoculation with GB 4-2, needle
photosynthetic efficiency and peroxidase activity is
increased resulting in improved disease resistance against
the needle pathogen Botrytis cinerea.
Inoculation of roots of the model plant Arabidopsis
thaliana with GB 4-2 resulted in promoted growth,
increased photosynthetic activity and increased resistance
in leaves against infection with the pathogenic fungus
Alternaria brassicicola. To elucidate the underlying
mechanisms, roots and leaves of A. thaliana seedlings
inoculated with GB 4-2 were used for microarray analyses.
Transcription rates of genes implicated in both major plant
signalling pathways involved in systemic resistance against
pathogens
(salicylic
acid-dependent
and
jasmonate/ethylene-dependent pathway) were modulated
during the interaction, indicating a novel, possibly GB 4-2specific signalling towards induced resistance in A.
thaliana.
P26: 11
Specificity in colonization pattern as well as fungal
identity of arbuscular mycorrhiza (AM) in Rutaceae
Appelhans M., Imhof S. and Weber H.
Philipps Universität Marburg, Germany;
[email protected]
The mycorrhiza of eight Rutaceae (Cneorum tricoccon L.,
C. pulverulentum Vent., Ruta chalepensis L., Orixa
japonica Thunb., Dictamnus albus L., Ptelea trifoliata L.,
Phellodendron amurense Rupr. and Zanthoxylum simulans
Hance) was investigated.
All species develop an AM characterized by an intracellular
phase in the outer cortex layers and an intercellular phase
with intracellular arbuscules and vesicles in the inner
layers.
This general pattern is differentiated between the species,
especially with regard to the longitudinal and tangential
extent of the intracellular outer cortex phase. In C.
pulverulentum this phase comprises up to eight cells in
longitudinal direction; in O. japonica only one row of cells
is colonized, which may be interpreted as a shorter, more
efficient way to reach the inner cortex layers. The other
species show intermediate colonization patterns.
The AM described here are intermediate stages between
Arum- and Paris-type, but the differences between the
species stress the structural continuum of AM pattern.
Molecular identification of the AM fungi in C. tricoccon,
R. chalepensis, O. japonica, and D. albus collected from
Mallorca, Malta and Marburg using partial 18S rDNA
revealed a narrowly specific group of fungi closely related
to Glomus hoi Berch & Trappe, and, thus, an unexpected
mycorrhizal specificity of Rutaceae also with regard to its
symbiont.
P26: 12
The influence of mycorrhization on herbivore-induced
volatile emission
Leitner M.1, Kaiser R.2, Hause B.3 and Mithöfer A.1
1
MPI für Chemische Ökologie, Germany; 2Universität
Salzburg, Austria; 3Leibniz-Institut für Pflanzenbiochemie,
Colonisation of a plant with arbuscular mycorrhizal (AM)
fungi is associated with drastic changes of the physiology
and ecology of the plant. Out of the multitude of effects
produced by AM fungi, plants undergo radical changes in
secondary metabolism, and become more resistant to all
kinds of pests, pathogens as well as phytophages.
Numerous studies documented changes of secondary
metabolism in the root, whereas effects on aboveground
plant parts have scarcely been reported. Regarding the
bioprotective capacity of mycorrhization against
POSTER ABSTRACTS
83
P26/P27
aboveground herbivores, results gathered so far are
inconsistent. The influences monitored range from positive
to negative, depending on the respective herbivore and
fungal species involved.
The present study aimed to assess changes in herbivoreinduced volatile emission, a mode of indirect defence,
relating to symbiosis with Glomus intraradices Schenck &
Smith. Two cultivars of Medicago truncatula Gaertn. were
used: cv. Jemalong A17, and a commercially available
mixture of cultivars, consisting of cv. Jemalong and cv.
Paraggio. These cultivars have been reported to differ in
their resistance against certain stresses. Thereby, cultivar
specificity of the reactions to mycorrhization was also
taken into account.
The induced volatile patterns clearly differed between the
cultivars. Mycorrhization slightly influenced the quantity of
some compounds emitted, whereas no qualitative changes
were traceable. Still, these differences were sufficient to
discriminate plants with distinct physiological status on the
basis of volatile emission.
P27: PLANT-VIRUS
INTERACTION
P27: 1
European mountain ash ringspot-associated virus
(EMARAV) - a new bunyaviral-type plant virus
Muehlbach H., Schlatermund N., Ludenberg I. and
Mielke N.
Biocentre Klein Flottbek and Botanical
Garden,Universitaet Hamburg, Germany;
[email protected]
Ringspots and mottling on leaves are typical symptoms of
the ringspot disease of European mountain ash (Sorbus
aucuparia L.). The causing agent is still unknown, but we
found a (-)strand bunyaviral-type RNA virus associated
with the symptoms. Its genome consists of four vRNAs,
each containing one ORF. The protein p1 encoded by
vRNA 1 shows similarity to RdRp of Bunyaviridae. RNA 2
and 3 encode a putative glycoprotein precursor and a
putative nucleocapsid protein, respectively. The function of
p4 is unclear. All RNAs share 13 conserved
complementary terminal nucleotides, as it is typical for ss()RNA-viruses. In situ-hybridisations revealed localisation
of vRNAs in leaf palisade parenchyma. We used real time
RT-PCR to get more information about the viral replication
cycle and virus localisation in various tissues. Such studies
on outdoor trees ask for critical controls, i.e. internal
standards. Therefore, five putative constitutively expressed
genes of S.a. were partially cloned, sequenced, and the
relative expression was analysed over one year. Ubiquitin
mRNA and 18S rRNA were found to be suitable standards.
Our results indicate highest accumulation of vRNAs in
early summer leaves.
P27: 2
Expression of the viral proteins p2 and p4 of European
mountain ash ringspot-associated virus (EMARAV) in
eucaryotic cells
Müller D.1, Thiemann A.1, Klode M.2, Mühlbach H.1
and Mielke N.1
1
University of Hamburg, Biocentre Klein Flottbek,
Hamburg, Germany; 2University of Kiel, Botanical Institute
84
POSTER ABSTRACTS
und Botanical Garden, Kiel, Germany;
[email protected]
In the past, symptoms of the so called ringspot disease on
European mountain ash (Sorbus aucuparia L.) have often
been described. Those symptoms appear as chlorotic
ringspots and mottling on leaves. A novel plant virus with
a genome of four potential ss(-) RNA molecules was shown
to be associated with the disease and is therefore called
European mountain ash ringspot-associated virus
(EMARAV). The genome encodes four putative viral
proteins: a RNA-dependent RNA polymerase (p1), a
glycoprotein-precursor (p2), a nucleocapsid protein (p3)
and a protein of unknown function (p4), which is
suspicious to be a suppressor of gene silencing and/or a
movement protein. Due to difficulties of purifying virus
particles, we were not able to gain native EMARAV
proteins from mountain ash leaves. For functional analysis
and antigen production we had to express the viral proteins
in eucaryotic systems. Since plant-infecting negative-strand
RNA viruses often also replicate in their arthropode
vectors, we decided to express two of the proteins, p2 and
p4, in Schneider 2 cells of Drosophila melanogaster. These
cells also allow to study the intracellular localisation and a
putative gene silencing suppressor capacity of the
recombinant proteins. In a second approach we used a
novel plant expression system in squash (Cucurbita pepo
L.), which can be efficiently inoculated with a recombinant
Zucchini yellow mosaic virus (ZYMV)-Vector carrying the
p4-ORF. (Mielke N., Mühlbach H.-P., 2007, J. Gen. Virol.,
88, p. 1337-1346; Chen T.-C. et al., 2005, J. Virol. Meth.,
129, p. 113-124)
P27: 3
Plant viruses as vectors for the expression of cre
recombinase protein in planta
Kopertekh L.1,2, Broer I.1 and Schiemann J.2
1
Rostock University, Germany; 2BBA, Braunschweig,
Plants virus vectors have been developed as a promising
alternative to other expression methods (transgenic or
transplastomic plants) and used for gene function
discovery, study of plant-virus interactions, investigation of
gene silencing and production of therapeutics and vaccines.
The aim of our study is developing plant virus vectors
expressing Cre recombinase to modify plant genomes in
vivo.TMV and PVX virus vectors were utilized to express
the Cre protein. Virus expression systems were tested by
Cre-mediated elimination of an intervening sequence (pat
gene flanked by two directly oriented lox sites) between
promoter and gfp gene in N. benthamiana plants.
Activation of gfp expression served as a visual marker for
successful recombination. Consequently, gfp fluorescence
was observed in PVX-Cre and TMV-Cre infected tissue.
Biochemical and molecular analysis confirmed the
presence of the Cre protein and precise excision of loxflanked sequence. The efficiency of recombination
evaluated at the level of plants regenerated from TMV-Cre
and PVX-Cre infected leaves varied from 57 to 82%,
respectively. We also showed differences in the heritability
of the recombination events between PVX-Cre and TMVCre expression vectors evaluated by a self-pollination
approach.These results suggest that both plant-Cre virus
vectors are functional in planta and produce enzymatically
active Cre recombinase. Cre expression by plant virus
vectors may have a future importance for specific gene
modifications, regulated gene expression and as an
alternative way to obtain marker-free transgenic plants.
P28
P28: RADIATION AND
SPECIATION
P28: 1
Characterising a floral variety of Capsella bursapastoris (L.) Medik. - decandric forms of shepherd´s
purse
Hameister S. and Neuffer B.
Department of Special Botany, University of Osnabrueck;
[email protected]
In several genera within the Brassicaceae family quite a
few evolutionary tendencies can be observed, which are
possibly involved in speciation, e.g. variations in flower
morphology. A floral variety of the shepherd’s purse
Capsella bursa-pastoris (L.) Medik. defined by
“staminiforme petals” is the focus of our studies. This
homeotic variety is characterized by a second whorl of
stamens instead of petals, which leads to a decandric flower
structure. Such a naturally occurring homeotic mutant,
known from several habitats in Central Europe and Russia,
provides the ability to study evolutionary trends. For this
reason a promising model system seems to have been
identified, which is going to be studied and established
from the molecular level up to field biology within this
project.
Here we focus on the chromosomal localisation of the
putative locus which is responsible for the transformation
of petals. For generating our mapping population we
crossed a decandric with a wild type parent, and then
obtained an F2 generation via selfing (University of Jena).
In this segregating population we found evidence for a
singular locus determining the petal morphology. Several
molecular marker systems are being used to generate a
linkage map which will be related to Arabidopsis thaliana
(L.) Hayek. The project is in cooperation with the
Department of Genetics, Jena, Guenter Theissen and Pia
Nutt
P28: 2
Chloroplast DNA haplotype diversity in Centaurea
section Cyanus
Löser C. and Hellwig F.
Institut für Spezielle Botanik, FSU Jena, Germany; [email protected]
Speciation is often accompanied by reticulate evolution in a
continuum of time scales making a distinction of prespeciation (lineage sorting) or post-speciation processes
(hybridization) impossible. We investigated the chloroplast
DNA haplotype distribution in the taxonomically difficult
Centaurea section Cyanus. Haplotype diversity is greatest
in southeast Europe. There is a tendency of decreasing
diversity towards the west. A phylogeny revealed three
major lineages of perennial species. One lineage is
confined to Anatolian species. The remaining two
haplotype groups are found predominantly in the
Centaurea triumfettii All. species group. Except of the
exclusively Anatolian lineage populations are often
polymorphic with respect to haplotype group and
haplotypes within each group. Delimiting species and
subspecies thus requires understanding population
historical processes including dispersal, gene flow and
isolation. A monophyly of annual species is not supported.
Rather annuality evolved repeatedly at the beginning of
diversification of Cyanus, perhaps coinciding with
aridification in the Mediterranean at the Pliocene –
Pleistocene transition, 1.8 mya.
P28: 3
Comparison of population genetics and ecophysiological
responses of the two closely related Deschampsia
wibeliana and D. cespitosa to habitat simulations.
Heydel F., Rudolph B., Rohwer J. and Jensen K.
Biocentre Klein Flottbek, Germany; [email protected]
Deschampsia wibeliana (Sond.) Parl. is an endemic species
growing in tidal freshwater- and brackish habitats of the
lower Elbe estuary. It is member of the Deschampsia
cespitosa complex, in which the relationships are not
completely resolved so far. Deschampsia cespitosa (L.) P.
Beauv. s. str. is a holarctic circumpolar distributed species
and is found in moist habitats. In the past, the natural
habitat had strongly been affected by the impact of
pleistocenic glaciation. The adaptation of D. wibeliana to
the tidal flood might be the result of natural divergent
selection on ecological traits followed by a reproductive
isolation to populations of D. cespitosa as putative
ancestor.
In the present study populations of both species along a
transect along the Elbe estuary will be analysed genetically
using molecular markers (AFLPs and microsatellites), in
order to compare the genetic structure of these two species.
In addition, controlled reciprocal ecological experiments
were started, in which the response of the two species to
tidal and non-tidal habitats will be examined. In this project
molecular and ecological methods shall be combined to
compare genotypic and phenotypic traits, as a contribution
to the investigation of sympatric radiation and evolution in
plants.
P28: 4
Cosegregation analysis of selfincompatibility alleles
from interspecific crosses between Diplotaxis species
(Brassicaceae) with different mating systems
Leffers H., Laschke C., Hurka H. and Neuffer B.
Department of Systematic Botany, University of
Osnabrück, Germany; [email protected]
Interspecific reciprocal crossing experiments between the
selfcompatible (SC) Diplotaxis cretacea and the
selfincompatible (SI) D. tenuifolia were carried out.
Diplotaxis cretacea is the derivative species of D.
tenuifolia as was confirmed by molecular markers. The aim
is to identify the S-alleles at the molecular level and their
cosegregation with the SI answer in the phenotype in order
to analyse the transition from SI to SC. It has to be seen
whether dominance relationships between S-alleles are
important for the understanding of the evolution of the
mating system. Since it is known that SI and SC species
often differ significantly in their pollen/ovule ratios, this
character state is also recorded.
P28: 5
Diplotaxis cretacea Kotov (Brassicaceae), an endemic
steppe plant of South-East Europe: Ice-age relic or
recent origin?
Lückmann K., Laschke C., Hurka H. and Neuffer B.
Department of Systematic Botany, University of
Osnabrück, Germany; [email protected]
POSTER ABSTRACTS
85
P28
Diplotaxis cretacea confined to calcareous outcrops in the
steppe regions of South-Eastern Europe, is most closely
related to Diplotaxis tenuifolia as molecular studies have
confirmed. In contrast to the self-incompatible (SI) D.
tenuifolia, the derivative taxon D. creatcea is selfcompatible (SC). It is not clear, whether D. cretacea can be
assessed as an ice-age relic as is believed in the literature,
or whether the populations are the result of recent dispersal
in these areas. During a collecting trip to the Voronesh and
Kursk regions in Russia in 2006, we were able to gather
samples of 15 populations of Diplotaxis cretacea. By
means of allozymes and RAPD-analyses, a fundamental
screening of selected populations was carried out.
Additionally, the length of the petals has been measured
and compared to D. tenuifolia, since it is known, that in the
course of time, SC-plants reduce the size of their flowers in
relation to their SI progenitors. Appraisal of the concluding
results will exhibit new and interesting insights regarding
the question of ice-age relic or recent dispersal, and will
enable us to draw further conclusions with respect to the
colonising behaviour of Diplotaxis cretacea.
P28: 6
Diversification and Ontogeny of the hooded staminode
in Marantaceae
Ley A., Pischtschan E. and Claßen-Bockhoff R.
Johannes-Gutenberg-Universität Mainz, Germany;
[email protected]
The flowers of Marantaceae (31 genera / 550 species) are
known for their irreversible explosive pollination
mechanism. The latter is based on the close synorganisation
of the cucullate (hooded) staminode and the style. By
differential growth of the two organs during bud
development the style is forced under tension. This tension
is released by the pollinator moving the `trigger appendage´
of the staminode. This `trigger mechanism´ is unique for
the Marantaceae and hypothesised to be a key-innovation
leading to the remarkable larger number of species
compared to the sister family Cannaceae. To elucidate
whether the structures involved in the trigger mechanism
diversified in the course of evolution we investigated
morphology and ontogeny of the hooded staminodes in 24
genera and 60 species. All staminodes correspond in their
general development and vascularisation confirming their
homology and single evolutionary origin. Considering
details, however, we identified nine different `trigger´ types
which are in accordance with the accepted clades of the
existing phylogeny of the family. We conclude that the
diversification of the hooded staminode reflects parallel
pathways to optimise the trigger mechanism - a hypothesis
still to be tested by experiments.
P28: 7
Does Allium tuvinicum and Allium rubens form a zone
of hybridisation? A molecular taxonomic study.
van Alen H. and Friesen N.
Botanical Garden of the University of Osnabrück,
In summer 2006 we have found inside the populations of
yellow flowering species Allium tuvinicum (N. Friesen) N.
Friesen (Section Rhizirideum) some hybrid plants with pink
flower. Possible second parents of this hybrid might be
local reddish flowering related species A. rubens Schrad. or
A. austrosibiricum N. Friesen. To proof the hybrid origin
and define the possible parents we used RAPD method,
sequencing of cpDNA (trnL-F spacer, psbA-trnH) and
86
POSTER ABSTRACTS
nuclear ITS fragments, cloning and Flow Cytometer
Analysis.
RAPD data clearly place pink hybrid taxa between A.
tuvinicum in one side and A. rubens and A. austrosibiricum
in another side. The maternal plant could be identified by
analysing the cpDNA sequences of the hybrid taxa which
matches with the data of A. tuvinicum. Also the sequences
of the nuclear ITS fragments of the hybrid taxa and it clons
points out, that A. tuvinicum is the mother plant. The Flow
Cytometer Data shows nearly identical DNA content in all
three species and hybrid.
P28: 8
Establishment of the German DNA-Bank-Network
Zetzsche H.1, Gemeinholzer B.1, Haszprunar G.2,
Stackebrandt E.3 and Wägele J.4
1
Botanischer Garten und Botanisches Museum BerlinDahlem - BGBM; 2Zoologische Staatssammlung München
- ZSM; 3Deutsche Sammlung von Mikroorganismen und
Zellkulturen - DSMZ; 4Zoologisches Forschungsinstitut
und Museum Alexander König - ZFMK;
[email protected]
A network of German DNA banks was established in
spring 2007, and is supported by the DFG. The network
covers the whole range of biological diversity, and will be
established and maintained by four partner institutions:
Botanic Garden and Botanical Museum Berlin-Dahlem
(BGBM), Bavarian State Collection of Zoology Munich
(ZSM), Forschungsmuseum Alexander Koenig Bonn
(ZFMK), and German Collection of Microorganisms and
Cell Cultures Braunschweig (DSMZ). The main focus of
the network is to enhance taxonomic, systematic, genetic,
and evolutionary studies by providing (1) at-cost
availability of DNA material (2) high quality, long-term
storage of DNA material on which molecular studies have
been performed, so that results can be verified, extended,
and complemented (3) full on-line documentation of each
sample, including the provenance of the original material,
the place of voucher deposit, links to previously published
molecular data and digital images of vouchers. Several
quality standards for long-term DNA storage will be
established concerning DNA extraction and lyophilization,
the technical infrastructure for storage at -80°C,
documentation including digitalization of voucher
specimens, standardization, public awareness, and
institutional sustainability. Promoting the continual
inclusion of well documented DNA samples by scientists is
crucial to the long-term success of the project, since
number and quality of accessible DNA samples determines
the usefulness of a DNA bank. The network is available via
an
online
portal
(http://www.bgbm.org/bgbm/research/dna/).
P28: 9
Farewell to dichotomous models of phylogeny:
Reconstructing patterns of low-level evolution in maples
Grimm G.1, Denk T.2 and Hemleben V.3
1
University of Tübingen, Institute of Geosciences,
Germany; 2Natural History Museum, Stockholm, Sweden;
3
University of Tübingen, Center of Plant Molecular
Biology (ZMBP), Germany; [email protected]
The evolutionary unfolding of Acer section Acer (17
species and subspecies from North America, East Asia, and
western Eurasia) is evaluated using splits-based networks,
ITS motif analysis, and morphology. Molecular analyses
P28
are based on 276 ITS clones obtained from 101 wild
specimens that represent all species and most subspecies.
Formerly recognized (sub)species are largely supported; in
addition, the combination of molecular and morphological
criteria leads to refined taxon circumscriptions and
supraspecific groups. Partly incompatible phylogenetic
signals captured in ITS sequences suggest that section Acer
underwent three major radiations, and unhindered
horizontal gene flow is indicated between ancestors of
extant taxa that are isolated at present times. Analyses of
chloroplast DNA (based on ~6600 nt from 6 regions) and
nuclear DNA (600 ITS sequences) also point to cases of
lineage sorting within Acer during the Tertiary. The level of
ITS derivation in section Acer corresponds to levels of
morphological differentiation and (palaeo) biogeographical
patterns. Based on our results, we question the utility of
cladistic approaches for inferring low-level evolution in
section Acer, mainly because of reticulate evolution. Our
findings in Acer are comparable to those in other Northern
Hemisphere tree genera, such as Fagus and Platanus. The
combination of methods used here allows to trace pathways
of low-level evolution and to analyse multi-signal data sets
with a less restricted (i.e. non-dichotomous) and dynamic
phylogenetic concept.
P28: 10
Molecular phylogeny, morphology and biogeography in
the genus Fosterella (Bromeliaceae)
Peters J.1,2, Ibisch P.2, Rex M.1, Schulte K.3,4, Weising
K.1 and Zizka G.3,4
1
Institute of Biology, University of Kassel, Germany;
2
Faculty of Forestry, University of Applied Sciences
Eberswalde, Germany; 3Research Institute Senckenberg,
Frankfurt a. M., Germany; 4Institute for Ecology, Evolution
& Diversity, Goethe-Universität, Frankfurt; [email protected]
The genus Fosterella currently includes 29 species of dry
and mesic habitats with a centre of distribution and
diversity in the Andes of Bolivia. The majority of species is
endemic and consists of rather small populations.
Morphological delimitation of species is difficult due to a
scarcity of characters. In an ongoing project we combine
molecular, morphological and biogeographical studies in
order to get insights in (1) the taxonomy and phylogeny of
the genus Fosterella, (2) the formation of endemic species
within the Bolivian Andes and (3) the origin and expansion
of the genus Fosterella. Here we present a molecular
phylogeny based on the combined sequence data of 4
chloroplast DNA regions (atpB-rbcL spacer, psbB-psbH
spacer, rps16 intron und matK gene) from 22 Fosterella
species. The evolution and systematic significance of a set
of morphological characters was assessed by MacClade
analysis. Evolutionary and biogeographical implications of
our results are discussed.
P28: 11
Natural selection or genetic drift? A comparison of
quantitative trait and neutral marker differentiation
among populations of Nigella degenii
Bittkau C.1, Jaros U.2, Tribsch A.2 and Comes H.2
1
Inst. für Spezielle Botanik, Johannes GutenbergUniversität Mainz, Germany; 2Department of Organismic
Biology, Salzburg University, Austria; [email protected]
Nigella degenii is a highly fragmented species of the N.
arvensis complex that contains four subspecies distributed
on c. 20 different Aegean islands. The subspecies occur in
similar habitats but differ in phenological, vegetative and
floral traits. Phenotypic divergence among these taxa has
long been interpreted to result from genetic drift driven by
range fragmentation and subsequent bottlenecks rather than
selection. Indeed cpDNA differentiation between
populations of N. degenii largely reflects postglacial island
fragmentation through rising sea level and genetic drift in
the near absence of gene flow since their time of common
ancestry.
A more direct insight into the process of phenotypic
evolution is expected to be achieved by a comparison of
neutral marker and quantitative trait differentiation (Fst and
Qst, respectively) among conspecific populations.
Divergence of quantitative traits should be similar to that of
allele frequencies at neutral genes if neither is subject to
selection. Thus the method allows falsifying the nullhypothesis that a given quantitative trait evolved by genetic
drift, in which case Qst will be either larger or smaller than
Fst.
We present a Qst-Fst contrast applied to five populations
representing three subspecies of N. degenii. Qst is based on
additive genetic variances of twelve quantitative characters
estimated from a nested paternal half-sibling design; Fst is
derived from AFLP and cpDNA markers.
P28: 12
On the Evolution of Southern African Cheilanthoid
Ferns (Pteridaceae subfam. Cheilanthoideae)
Eiserhardt W.
Universität Hamburg / Biocenter Klein Flottbek, Germany;
[email protected]
Cheilanthoids are a group of mainly xerophytic ferns with
nearly worldwide distribution. In this group, generic
circumscriptions and phylogenetic hypotheses are difficult
to infer from morphological characters, especially among
the large genera Cheilanthes, Notholaena, Pellaea and
Doryopteris. The problem is thought to be due to
homoplasy of adaptations to drought. According to
previous studies, DNA sequence data can provide valuable
information on phylogenetic relationships in Cheilanthoids.
This study integrates a number of Southern African species
into a global molecular phylogeny of Cheilanthoid Ferns,
inferred from chloroplast DNA sequence data (rbcL).
These sequences of Southern African species were aligned
with sequences of Cheilanthoids from different regions
worldwide, as far as available from GenBank. Preliminary
results suggest that Ch. rawsonii nests in a group of North
American taxa of Cheilanthes. This could be due to long
range dispersal of spores. Some of the other species
traditionally assigned to Pellaea and Cheilanthes share one
clade, together with Doryopteris concolor. Doubts about
the traditional generic concepts are therefore confirmed.
Most of the analyzed Southern African species of
Cheilanthes form a second clade possibly representing a
speciation event in the context of the Cape Flora. As this
clade is not unequivocally supported and resolved using the
rbcL data set, analysis of further sequences is proposed to
support the speciation hypothesis.
POSTER ABSTRACTS
87
P28
P28: 13
Origin and taxonomic status of Lycopersicon: Evidence
from the evolution of the rDNA 5’ external transcribed
spacer
Hemleben V.1, Komarova N.1, Grimm G.2 and Volkov
R.3
1
University of Tübingen, Center of Plant Molecular
Biology, Germany; 2University of Tübingen, Institute of
Geosciences, Germany; 3University of Chernivts,
Molecular Genetics and Biotechnology, Ukraine;
[email protected]
The taxonomic status of tomatoes (Lycopersicon spp.) and
their relationship to the members of section Petota of
Solanum is studied using the external transcribed spacer (5’
ETS) of nuclear rDNA in 33 Solanum-Lycopersicon
species. The 5’ ETS can be subdivided into a variable
region (VR) characterized by duplications/amplifications of
structural elements and a conservative region (CR)
evolving stepwisely by base substitutions. Phylogenetic
reconstruction based on CR revealed three major groups
within Solanum section Petota. A paraphyletic ancestral
group 1 includes non-tuber-bearing species series
Etuberosa as well as tuber-bearing Central American
diploids. One of the derived clades (group 2) contains nontuber-bearing species of series Juglandifolia and series
Neolycopersicon (tomatoes), which are imbedded in section
Petota; the other (group 3) embraces all tuber-bearing
South American species and Central American polyploids.
Each group exhibits a specific 5’ ETS structural VR
variant. Variant D of group 3 is characterized by a cluster
of down-stream subrepeats and evolved directly from the
most ancestral variant A found in group 1. Variants B/C
specific for group 3 represent a parallel lineage of
molecular evolution. Our analysis indicates that tomatoes
are derived members of section Petota, closely related to
series Juglandifolia, and originated from a heterogeneous
pool including tuber and non-bearing Solanum species.
From a phylogenetic systematic viewpoint, treating
tomatoes as a distinct genus is not justified.
P28: 14
Phylogenetic implication of the chloroplast rpoC1
intron loss in the Aizoaceae (Caryophyllales)
Schmidt S., Thiede J. and Rudolph B.
University of Hamburg, Germany;
[email protected]
Relationships within the Aizoaceae remained in many cases
unresolved, especially among the four subfamilies.
Previous phylogenetic studies with markers such as cpDNA
trnL-F, rps16 and nuclear ITS sequences could not provide
any resolution within the tribe Ruschieae. Since a study of
Wallace & Cota (1996) detected species within this tribe
with and without the rpoC1 intron, a representative sample
of 69 species from all recognized infrafamilial taxa of the
family Aizoaceae was surveyed for the presence/ absence
of the intron. The chloroplast rpoC region consists of two
genes, rpoC1 and rpoC2, and is located within the LSC
region of the plastid genome in most angiosperms. These
genes, together with rpoB, encode three subunits of the
cpRNA polymerase. The rpoC1 gene is interrupted by a
single intron in most, but not all, land plants, and thus is of
systematic importance. PCR fragments of the studied
samples fall into two size classes: a long fragment of
approx. 1200 bp, and a short fragment of approx. 500 bp,
which was found in all examined samples of the tribes
Drosanthemeae and Ruschieae of the subfamily
88
POSTER ABSTRACTS
Ruschioideae. The length difference of about 700 bp
corresponds to the length of the intron (738 bp in tobacco).
Sequencing of the short fragment from Monilaria
moniliformis (Aizoaceae) revealed the precise excision of
the intron. We conclude that the intron is lacking in all
species of the tribes Drosanthemeae and Ruschieae of the
subfamily Ruschioideae, thus providing valuable PCRbased, sequence- and morphology-independent evidence
for the monophyly of this lineage.
P28: 15
Phylogeny of Amorphophallus using molecular markers
Claudel C., Rudolph B. and Rohwer J.
Uni HH - Biozentrum Klein Flottbek, Germany;
[email protected]
Amorphophallus titanum (Araceae) has drawn much
attention from scientists and the public since its discovery
in 1887 by Odoardo Beccari. This spectacular plant is the
best known species of a paleotropical genus of about 200
species. Using molecular markers (Internal transcribed
spacer and floricaula/leafy gene intron 2) we analysed 190
samples representing 150 different species and investigated
the phylogenetic relationship within the genus and its
phylogenetic position within the family. Seven major
clades could be detected, corresponding to the main areas
of distribution of Amorphophallus. The subclades are well
resolved and have mostly a high bootstrap support. The
gene pool of most Amorphophallus species seems to be
very homogenous - probably due to recent radiation events
and/or a high degree of endemism – therefore, two species,
A. titanum and A. konjac, were analysed more closely. (1)
Regarding A. titanium, this threatened species is cultivated
as ornamental plant in botanical gardens and it is a crowd
puller while flowering. So it is planned to establish
conservation programs for botanical gardens supported by
molecular markers in order to conserve an as large as
possible gene pool. (2) Amorphophallus konjac has a
growing economical importance as crop plant. Therefore,
the establishment of a marker assisted breeding program is
planned. For these two objectives, AFLP and microsatellite
marker techniques are being developed.
P28: 16
Reconstructing the adaptive radiation of the ephiphytic,
neotropical fern genus Pleopeltis (Polypodiaceae)
Otto E.1 and Schneider H.2
1
Universität Göttingen, Germany; 2Natural History
Museum London, UK; [email protected]
The phylogeny of the Pleopeltis clade within the
Polypodiaceae is inferred using four chloroplast genome
markers: The coding regions rbcL and rps4 and the noncoding regions rps4-trnS IGS and trnL-trnF IGS. The
taxonomic sampling comprises one or more samples of
more than 40 fern species earlier classified as members of
the genera Dicranoglossum, Microphlebodium, Neurodium,
Pleopeltis, Polypodium, and Pseudocolysis. Previously
published phylogenetic analyses have suggested that these
species form a monophyletic lineage within an assemblage
of mainly Neotropical ferns that were partly assigned to the
polyphyletic genus Polypodium. Our results show that there
is a need to redefine the genus Pleopeltis because the group
in its current circumscription is not monophyletic. This
supports the previous suggestion to combine all species that
fall into the Pleopeltis clade in one genus. Persistent scales
on the lamina and/or rachis are a putative apomorphy of
this genus, whereas peltate paraphyses evolved at least
P28/P29
twice in this clade. The inferred phylogeny will not only
shed light onto the classification of one of the most
widespread and species rich genera in Polypodiaceae but
will also allow us to unravel the adaptive radiation of these
epiphytic ferns. The key innovation that might have
triggered their diversification is the tolerance of water
stress including poikilohydry as an extreme response.
P28: 17
Sexual Against Asexual Reproduction in Plants: A
Comparison of Population Structures of two South
American Water Hyacinths Eichhornia azurea and E.
crassipes
Rudolph B.1, Bartel S.2 and Parolin P.2
1
Germany; 2Max-Planck-Institute for Limnology, Tropical
Ecology, Plön, Germany; [email protected]
The invasive aquatic plant Eichhornia crassipes
(Pontederiaceae) is native in the freshwaters of the Amazon
basin. Due to its wonderful flowers it has been introduced
to the tropics worldwide where it spread out. This species
proliferates aggressively by reproducing mainly
vegetatively. It forms daughter rosettes within days
building tons of biomass which cover the water surface and
destroy the water ecosystem. Nowadays it is listed among
the world's worst invaders. In comparison, the closely
related, co-occurring and less invasive E. azurea
reproduces mainly sexually by seed dispersal.
In this study, we compared the genetic structure of both
species in their native range. Molecular analyses of each of
three populations were carried out using AFLPs and
cpRFLPs. Genetic distance trees and PCOs based on AFLP
data show contrasting differentiation processes of the two
species in the main investigation area in Uruguay and
Argentina: Whereas within the generative reproducing E.
azurea we identified a differentiation of populations from
North to South, we found no separation of populations of
the vegetatively reproducing E. crassipes. Extending the
investigation area to the whole of South America, we
discovered a differentiation event in E. crassipes showing a
western (Peruvian) population separated from the main
population (Uruguay, Argentina, Brazil, Peru and
Colombia). This differentiation is supported by different
chloroplast haplotypes.
P28: 18
Taxonomy and phylogeny of the genus Deuterocohnia
Mez (Bromeliaceae): insights from morphological and
molecular studies
Schütz N.1, Wagner N.1, Weising K.1 and Zizka G.2,3
1
Institute of Biology, University of Kassel, Germany;
2
Research Institute Senckenberg, Frankfurt/Main,
Germany; 3Institute for Ecology, Evolution & Diversity,
Goethe-Universität, Frankfurt; [email protected]
The genus Deuterocohnia Mez (Bromeliaceae) comprises
about 17 species with a distribution centre in the Andes of
southern Bolivia and northern Argentina. Some species of
the genus occur in high altitudes exceeding 3500m a.s.l.
Typical habitats are dry, rocky slopes or rock faces.
Depending on the presence or absence of a woody,
perennial inflorescence and other aspects of habit, the
species of the genus had traditionally been assigned to
either Abromeitiella Mez or Deuterocohnia Mez. However,
this division was challenged more recently, and the two
genera have been synonymized. Our ongoing project
involves a detailed morphological, biogeographical and
molecular systematic analysis of the genus. Our main aims
are (1) to set up a full nomenclatural revision of the genus
comprising morphological description and geographical
distribution patters, and (2) to assess its infrageneric
phylogeny and evolution, also including a critical
evaluation of whether the union of Abromeitiella and
Deuterocohnia is justified. In the present contribution we
(1) compile a set of morphological characters and their
potential systematic relevance, and (2) present first
molecular data, based on the comparative sequence analysis
of intergenic chloroplast DNA-regions.
P28: 19
Towards a Breeding Program for the Conservation of
Genetic Diversity: Molecular Analysis of the
Cycadopsida
Timm M., Rudolph B., Schirarend C. and Rohwer J.
The Cycadopsida (Spermatophyta, Gymnospermae) had
their main period of radiation from the Permian to the
Jurassic. They include some 130 recent species, which are
often considered as "living fossils", representing but a
fraction of their earlier diversity. They are distributed in a
discontinuous area over the worldwide tropics and many of
them are endangered in their natural populations. The aim
of the present study is the establishment of a breeding
program for the restoration and conservation of the genetic
variability of the Cycadopsida preserved in Botanical
Gardens, starting with individuals from the Botanical
Garden of the University of Hamburg as a model system. In
preparation for this project a population analysis with fast
and easy to use molecular markers was established. So far a
set of 100 individuals of about 48 different species in ten
genera was analysed using AFLP markers to obtain
individual genetic fingerprinting. The collection of unique
combinations of molecular characters of each individual in
a database will be a basis for the establishment of a
breeding book as support for conservation and exchange of
plants among different living collections. Preliminary
results indicate that the AFLP markers used not only allow
to obtain individual fingerprints, but also to distinguish
among the different genera.
P29: REACTIVE OXYGEN
P29: 1
COMPARATIVE ANALYSIS OF PEROXIDASE
ISOFORMS FROM PEA ROOT CELL WALL
Kukavica B.1, Veljovic Jovanovic S.1, Menckhoff L.2
and Lüthje S.2
1
Center for Multidisciplinary studies, Yugoslavia;
2
University of Hamburg, Biocenter Klein Flottbek, Plant
Physiology; [email protected]
Class III peroxidases have major functions in several
biosynthetic pathways, cell wall modification and stress
responses etc. In the present work cell wall was isolated
from roots of two week old pea (Pisum sativum L.) plants.
Four peroxidase isoforms were identified in the ionically
cell wall fraction (56 kDa, 46 kDa, 44 kDa and 41 kDa)
whereas one peroxidase isoform (70 kDa) was detected in
the covalently cell wall bound fraction. IEF profiles
showed that covalently bound peroxidases were anionic (pI
POSTER ABSTRACTS
89
P29
3.6 to 4.6) and that ionically-bound cell wall fraction
contained mostly cationic peroxidase isoforms. Lectins,
like concanavalin A and wheat germ agglutinin slightly
increased activity of ionically cell wall bound peroxidases
and decreased peroxidase activity in covalently cell wall
fraction. A small increase in peroxidase activity and
changes in peroxidase electrophoretic mobility of ionically
cell wall bound peroxidases was observed after
deglycosylation of native proteins. Deglycosylation of
covalently bound proteins by endoglycosidases decreased
peroxidase activity for 26, 36 and 38 % respectively, while
PNGase F slightly increased peroxidase activity. The
distinct enzymatic properties (molecular masses, pI, Km for
H2O2 and phenolic substrates, glycosylation) of ionically
and covalently cell wall bound peroxidase isoforms
suggest that they may have different physiological
functions.
P29: 2
Distribution and subcellular localisation of
tocochromanols in plant cells
Brueckner K., Krupinska K. and Falk J.
Institute of Botany, Christian-Albrechts-University, 24098
Vitamin E represents a group of lipophilic antioxidants
including closely related tocopherol and tocotrienol
derivatives, also known as tocochromanols. Although
tocochromanols are exclusively synthesized in chloroplasts
of photosynthetic organism, their role in plants has been far
less described than in humans. Apart from their role as
antioxidants, tocopherols have been suggested e.g. to
participate in intracellular signalling as well as in the
regulation of gene expression under stress conditions.
Because of its lipophilic properties tocopherols are
supposed to be major components of cell membranes.
However, up to date only inconsistent data about the
intracellular distribution and possible transport of vitamin E
in plant cells are available. To understand the functions of
tocopherols it is therefore essential to study their exact
cellular localisation.
The primary aim of this research is to verify the distribution
of tocopherols in subcellular membranes of plant cells.
First experiments with subcellular fractions of cauliflower
tissue indicate that tocopherols are present outside of
plastids, too. In addition, the identification of proteins
involved in the intracellular distribution of tocopherols is a
main task of the present study. To date, tocopherol-binding
proteins have been identified in humans and animals, but
are unknown in plants.
P29: 3
Drought Induced Changes of ROS Scavenging Enzymes
in Apoplastic and Symplastic Compartments of Rolling
Leaves
SARUHAN N.2, TERZI R.1, SAGLAM A.1, NAR H.1
and KADIOGLU A.1
1
KARADENIZ TECHNICAL UNIVERSITY,Turkey;
2
RIZE UNIVERSITY, Turkey; [email protected]
Reactive oxygen species scavenging capacities of
apoplastic and symplastic compartments of leaf were
studied parallel to leaf rolling resulted from water deficit.
In addition, stomatal conductance and water potential of
leaves were followed through rolling periods. This study
was conducted on Ctenanthe setosa (Rosc.) Eichler
.
90
POSTER ABSTRACTS
(Marantaceae), an ornamental plant exhibiting leaf rolling.
The plants were vegetatively propagated and subjected to
drought. For apoplastic and symplastic extraction, the
leaves were harvested in 25 %, 54 % and 73 % degrees of
leaf rolling. Reduced water potential and stomatal
conductance showed that water balance of plants was
affected by drought. Apoplastic and symplastic
compartments of the leaf had superoxide dismutase (SOD),
guaiacol peroxidase (GPX), catalase (CAT) and ascorbate
peroxidase (APX). Notable increases for GPX and CAT
activities were observed in symplast and apoplast of leaf.
On the other hand, changes of SOD activity in leaf
symplastic and apoplastic spaces were not statistically
different from each other except for 73% leaf rolling in
which significant activity increase for apoplastic SOD was
observed. Symplastic APX did not change in leaf.
Apoplastic APX activity in leaf increased with increasing
of leaf rolling. In addition, the highest APX activity in
apoplast was observed at 73 % degree of leaf rolling. In
conlusion balance between these two compartmens is
changed by water deficit to cope with adverse effects of
stress in rolling leaves of C. setosa which have an effective
antioxidant defence mechanism.
P29: 4
H2O2 production mechanisms in the apoplast of
suspension-cultured cells of Picea abies
Kärkönen A.1, Warinowski T.1, Salonvaara S.1, Teeri
T.1, Simola L.2 and Fry S.3
1
Dept of Applied Biology, P.O. Box 27, University of
Helsinki, Finland; 2Dept of Biological and Environmental
Sciences, Univ. of Helsinki, Finland; 3Edinburgh Cell Wall
Group, University of Edinburgh, UK;
[email protected]
The cell culture of Picea abies (Norway spruce) is a unique
system where free lignin, structurally similar to wood
lignin, is constitutively released into the culture medium.
The removal of H2O2 from the medium diminished the
amount of extracellular lignin produced, pointing out the
importance of peroxidases in monolignol activation. This
observation led to the question of the origin of H2O2 in the
cell wall during lignin formation.
H2O2 generation mechanisms in the apoplast of spruce cells
were studied by adding substrates and inhibitors of
enzymes possibly involved in H2O2 generation into the
medium and measuring H2O2 levels in the medium. In
comparison, the mechanisms of H2O2 production after
elicitation were evaluated by use of cell wall fragments of
Heterobasidion parviporum as an elicitor. At least two
enzymic systems producing H2O2 were observed to be
present in the apoplast, one inhibitable with sodium azide,
an inhibitor for haem-containing enzymes, the other with
diphenylene iodonium, DPI, an inhibitor for flavincontaining enzymes.
In order to study the role of plasma membrane enzymes for
the apoplastic superoxide and H2O2 generation, plasma
membranes of spruce cells were purified by aqueous twophase partitioning and the existence of enzymes mediating
trans-plasma membrane electron transport studied.
Biochemical assays showed the existence of a membranebound enzyme(s) capable of reducing tetrazolium salts,
indicators for superoxide. Cloning of the respiratory burst
oxidase homologue of lignin-producing spruce cells is
underway. These data will be discussed
P29/P30
P29: 5
Investigation on the cascade of the detoxification
enzymes in Typha latifolia grown under heavy metals
stress
Lyubenova L. and Schröder P.
GSF, Germany; [email protected]
Typha latifolia has been investigated as plant species
effective
in
phytoremediation. Although
aquatic
macrophytes are well known to accumulate heavy metals,
the toxicity effects of cadmium on protective enzyme
mechanisms of Cattail have so far not been investigated.
Typha latifolia plants were therefore treated with different
concentrations of CdSO4: 10, 50, 100 and 250µM, for 72
days. A linear correlation between treatment concentration
and cadmium was found in the treated rhizomes and leaves
were found up to 10 µM metal accumulation in the
rhizomes. The reverse can be said about the other signs of
metal stress: the total chlorophyll and carotene content in
the investigated plants decreased with increasing cadmium
concentration. The photosynthesis and the transpiration
were measured as well.As cadmium causes ROS generation
in chloroplasts and peroxisomes, which induces severe lipid
peroxidation and leads to formation of lipid radicals and
reactive aldehyds, malondialdehyde was measured to
demonstrate lipid degradation with the influence of
cadmium. Protective mechanisms against heavy metal
toxicity include enzymes and reactions of the HalliwellAsada cycle, which also have been observed: superoxide
dismutase, catalase, glutathione peroxidase, glutathione
reductase,
ascorbate
peroxidase,
dehydroascorbate
reductase, peroxidase and not least the glutathione Stransferases (GST´s) react to heavy metal treatment in
Typha.GST aqctivity was measured for four different
model substrates (CDNB, DCNB, NBC and NBoC) and
one herbicide (Fluorodifen). The results are critically
discussed.
P30: REDOX REGULATION
P30: 1
A transcription factor related to apetala2 (RAP2) as
putative redox regulator for 2-Cys peroxiredoxin A
(2CPA)
Birkmann S., Klein P., Shaikhali J. and Baier M.
Bielefeld University, Department of Biochemistry and
Physiology of Plants; [email protected]
The expression of the plant 2-Cys peroxiredoxins (2CP) is
redox regulated, and in the case of 2CPA a redox sensitive
promotor region has been characterized (Baier et al., 2004).
This promotor region was used in a yeast one hybrid
approach with an Arabidopsis thaliana cDNA library to
identify trans activating elements. One of the obtained
clones showed 100% identity with a putative AP2 domain
containing transcription factor belonging to the ERF
subfamily. In the latest work it could be shown that this
transcription factor exhibits a GCC- box binding domain
(GBD) which is typical for the ERF- subfamily and
responsible for recognition. Via electrophoretic mobility
shift assay (EMSA) it was proven that this Rap2 binds to a
coupling element 3-like (CE3-like) element sequence
(GCGA) found in the 2CPA promotor. The underlined
nucleotides were determined as responsible for binding.
Transient expression analysis in Arabidopsis mesophyll
protoplasts showed the ability of Rap2 to bind to the 2CPA
promoter, thereby activating its expression. In addition
redox depending intermolecular disulfide bond formation
was observed in vitro which led to dimerisation or
oligomerisation. Under reducing conditions the binding of
Rap2 to the 2CPA promotor was impaired which might
lead to decreased transcriptional activity. Furthermore
Rap2 could be mainly detected in the nucleus as expected
for a putative transcription factor. The results support the
conclusion that Rap2 is a trans activator for 2CPA which
regulates its expression in a redox dependent manner.
P30: 2
Anoxia-induced sub-cellular crosstalk of pH and redox
changes monitored with recombinant fluorescent
indicators
Schmidt H.1, Thierbach K.2 and Plieth C.1
1
2
BZH, Ruprecht-Karls-Universität Heidelberg;
[email protected]
Anoxia is an abiotic stress factor with impact on
transcription, enzyme activities and cytoplasmic pH. Less
is known about possible oxygen receptor(s) and the
directive signalling network. Therefore, we started to
investigate the sub-cellular crosstalk of pH and redox
environment using PtGFP and sm2roGFP indicative for
these two generic parameters and targeted to different
organelles.
Anoxia produces an acidification of up to 0.5 pH-units in
the cytoplasm within a few minutes. Comparison of the
kinetics reveal that this is accompanied by subsequent
peroxisomal, mitochondrial, and stromal pH decreases. The
luminal pH in the thylakoids seems to remain unaffected by
anoxia. The kinetics suggest that cytoplasmic acidification
is the primary effect counterbalanced by different
regulation mechanisms. Anoxia-induced pH shifts are
reversible. Their cause, however, is still a matter of debate.
Anoxia also induces changes of the redox environment in
the cytoplasm, the ER, mitochondria and peroxisomes.
Apart from mitochondria all compartments display a
reduction of the indicator after onset of anoxia. Here, the
redox change in the peroxisomes is likely to be the primary
effect that crosstalks to other compartments. We assume
that the anoxia-induced oxidation of the indicator in
mitochondria reflects the formation of reactive oxygen
species (ROS) in this organelle. The reduction in the ER
could be caused by a consumption of alternative electron
acceptors under anoxia which normally maintain the
relatively high redox potential needed for oxidative protein
folding in this compartment.
P30: 3
Characterisation of chloroplast redox-regulation and
the role of G6PDH using ferredoxin knock-out mutants
of Arabidopsis thaliana
Voss I., Holtgrefe S., Backhausen J. and Scheibe R.
Department of Plant Physiology, University of Osnabrück,
Plants are unique in their property to maintain a relatively
constant redox state of the chloroplasts under a broad range
of conditions, even upon pronounced changes in their
environment. On the other hand, sustained imbalances in
the redox state of the chloroplast lead to alterations in gene
expression. However, there is still discussion, whether the
redox signals originate from the thylakoid membranes or
from the stroma. Therefore, we have used transgenic plants
with stably decreased leaf ferredoxin content in order to
obtain a better insight into chloroplast redox regulation.
POSTER ABSTRACTS
91
P30
Ferredoxins play a central role in photosynthetic redox
reactions by catalyzing the transfer of electrons to various
acceptors. Under optimal conditions, most electrons will be
used for NADP reduction and other reductive steps of C, N,
and S assimilation. Homozygous A. thaliana T-DNA
insertion mutants for one of the two leaf ferredoxins
(At1g60950) display a strong phenotype even under
moderate light intensities, showing all signs of high-light
acclimation as is expected upon over-reduction of the
electron-transport chain. In the knock-out lines, the stroma
is in a more oxidized state than in wild-type plants. Due to
the lack of electrons in the stroma, G6PDH activity
increases in the knock-out plants under normal light
conditions. This implies that the oxidative pentosephosphate pathway is used in the light to generate NADPH
for reductive processes and for detoxification of
accumulating ROS due to acceptor limitation at PSI.
P30: 4
Characterization of a putative Fe-S-protein in the
cyanobacterium Synechococcus elongatus PCC 7942
Pietsch D., Pistorius E. and Michel K.
Molecular Cell Physiology, Bielefeld University, 33615
Iron frequently is a limiting nutrient in natural habitats.
Therefore, cyanobacteria as other photosynthetic organism
have developed multiple strategies to adapt to iron
deficiency. For Synechococcus elongatus PCC 7942 it has
been shown that under iron deficiency photosystem II
becomes protected by IdiA and PS I is modified by IsiA
forming a new chlorophyll a containing antenna around the
reaction centre. The expression of IdiA is regulated by the
positively acting transcription factor IdiB. IdiB is located in
an operon together with the orf5 gene resulting in a
polycistronic mRNA being up-regulated under iron
deficiency and in the stationary growth phase. ORF5
represents a putative Fe-S-protein with similarities to the
Fe-S-containing substrate-binding subunit NuoE of the
NDH I complex in Escherichia coli. Since the substratebinding subunit(s) of the NDH I complex in cyanobacteria
are still unknown, the function of the ORF5 protein in
Synechococcus elongatus PCC 7942 was investigated.
Insertial inactivation of the orf5 gene in Synechococcus
resulted in merodiploid mutants, suggesting that this
protein is essential for growth. Extended comparative
investigations of Synechococcus wildtype and the
merodiploid ORF5-free mutant were performed with
respect to the expression of known iron-regulated proteins
and with respect to modifications of the photosynthetic and
respiratory electron transport chain. Moreover, an
antiserum against the ORF5 protein was raised in a rabbit,
and the localization of ORF5 was investigated. The
possible function of the ORF5 protein will be discussed.
P30: 5
Comparison of plasma membrane redox protein
profiles of pea (Pisum sativum L.) and maize (Zea mays
L.) roots
Hopff D.1, Buck F.2 and Lüthje S.1
1
University of Hamburg, Biocenter Klein Flottbek, FRG;
2
University hospital Hamburg-Eppendorf, Inst. Cell.
Biochem. Neurobiol. FRG; [email protected]
Iron, copper and zinc have been detected in plasma
membrane fractions. Zinc itself is not redox active, whereas
copper and iron participate in electron transfer reactions.
92
POSTER ABSTRACTS
Nowadays plasma membrane redox systems appear well
established. Besides, b-type cytochromes, peroxidases,
NAD(P)H-dependent oxidoreductases and a Cu/Znsuperoxide dismutase (SOD) have been detected in plant
plasma membranes. Pea (Pisum sativum L.) and maize (Zea
mays L.) differ in their iron uptake strategy. A trans-plasma
membrane flavocytochrome b appears to reduce the iron
outside the cell in pea (Strategy I), whereas a membranebound cytochrome b5 reductase was suggested to reduce the
iron inside the cell (i.e. after uptake) in maize (strategy II).
In the present study plasma membranes have been isolated
from roots of pea and maize. After solubilization by
dodecyl maltoside proteins were separated by 2D-gel
electrophoresis (IEF/SDS-PAGE). Native-PAGE was
prepared to obtain zymograms and identify redox activities.
Heme- and copper-containing proteins, NAD(P)H-oxidase
like enzymes, ferric-chelate reductase activity, peroxidases
and SOD were visualized by specific staining procedures in
the gels. The establishment of these methods allows us a
comparison of protein profiles of plants grown under iron
deficiency with control plants and showed that iron
deficiency alters redox protein profiles. Protein spots,
corresponding to the detected redox activities were cut out
and peptide sequence analysis was carried out by ESIQTof-Ms/Ms.
P30: 6
Cytosolic TypeII Peroxiredoxins in Arabidopsis
thaliana – Towards Understanding their Role in
Antioxidant Defence and Redox Signalling
Jacob S.1, Finkemeier I.2 and Dietz K.1
1
Universität Bielefeld, Germany; 2Department of Plant
Sciences, University of Oxford, UK; [email protected]
Peroxiredoxins are evolutionary old and often abundant
thiol-based peroxidases that are grouped into four
peroxiredoxin subfamilies. In plants, the subfamily
containing the largest number of members is the group of
typeII peroxiredoxins. The genome of Arabidopsis thaliana
codes for six different genes of this group. In addition to
one member each being located in the mitochondrion
(PrxIIF) and in the plastid (PrxIIE), three different
cytosolic typeII peroxiredoxins could be identified in A.
thaliana: namely PrxIIB, PrxIIC and PrxIID. Expression of
PrxIIA could not be observed until now. In contrast to other
peroxiredoxins, PrxIIC showed a highly inducible
transcript under various stress conditions whereas the
transcript level in untreated leaf material of A. thaliana was
low. Taking into consideration that in vitro activity
measurements showed a high capacity for the H2O2
detoxification with a KM-value of 213 µM and vmax of 666
µmol H2O2/(min*µmol Prx), PrxIIC is a promising
candidate for studying the role of cytosolic Prx in
antioxidant defence and redox signalling in the cell,
respectively. In this context, the analysis of T-DNA
knockout plants are expected to give further insights into
the involvement of PrxIIC and the other cytosolic
peroxiredoxins in defence and signalling.
P30: 7
Identification and functional characterisation of redoxregulated DNA-binding proteins in higher plant
chloroplasts
Steiner S., Schröter Y., Matthäi K. and Pfannschmidt T.
Lehrstuhl für Pflanzenphysiologie, Friedrich Schiller
Universität Jena; [email protected]
P30
Chloroplasts are plant cell organelles and sites of important
biochemical reactions like photosynthesis. They possess
their own genome and a complete gene expression
machinery responsible for the realisation of its genetic
information.
Recent studies revealed a strong regulatory influence of the
photosynthesis on plastid gene expression. Among others,
the redox state of the plastoquinone pool as part of the
photosynthetic electron transport chain provides a signal
towards the transcription of plastid photosynthetic genes
and thus couples photosynthesis to its own gene expression.
This feedback control maintains the acclimation of the
photosynthetic apparatus to changing environmental cues.
Until now, the transduction of this redox signals is not yet
understood. Recent studies suggested a crucial role of novel
regulatory proteins such as transcription factors. We are
studying the role of novel plastid DNA binding proteins in
response to changing light conditions. For this purpose we
grow mustard plants under a specific light regime to induce
strong changes in plastid gene expression. We isolate
chloroplasts and enrich DNA binding proteins by heparinsepharose-chromatography followed by DNA-affinitychromatography. We further established fluorescence based
electrophoretic mobility shift assay to scan the promoter
regions of photosynthetic genes for binding sites of novel
regulatory factors. These proteins will be functionally
characterised and identified to gain insights in the
regulation of photosynthetic gene expression in the context
of changing environmental conditions.
P30: 8
Identification of redox regulated DNA-binding proteins
in higher plant chloroplasts by mass spectrometry
Schröter Y., Steiner S. and Pfannschmidt T.
Friedrich-Schiller-University Jena, Plant Physiology;
[email protected]
Illumination of plants with light which preferentially
excites photosystem I (PSI) or photosystem II (PSII) causes
an oxidation or reduction of the electron transport chain,
respectively. The redox state triggers the activation of
short-term and long-term acclimation reactions towards
changing light conditions. The short-term response (state
transition)
is
driven
by
phosphorylation
or
dephosphorylation of the light harvesting complex II
(LHCII), which migrates to the photosystem which is less
excited. The long-term response comprises the changing of
gene expression for photosystem subunits to adjust
photosystem stoichiometry. The expression of plastid
encoded photosystem subunits is controlled by nucleus
encoded transcription factors.
The identification of transcription factors which mediate
the expression of plastid genes in response to redox signals
is the aim of the present work. Therefore, redox signals
were induced by cultivation of Sinapis alba under light
conditions favouring either PSI or PSII followed by a
change into the respective other light. Chloroplasts were
isolated and DNA-binding proteins were enriched by
heparin-sepharose- and phosphocellulose-chromatography.
Subsequently, the DNA-binding protein containing
fractions were separated by 2D-SDS-PAGE and silver
stained. After a tryptic in-gel digestion of gel spots,
proteins were identified via LC-ESI-MS and database
analysis.
P30: 9
Proteomic analysis of Arabidopsis thaliana leaves after
treatment with cyclopentenone oxylipins
Dueckershoff K., Mueller S., Berger S., Reinders J. and
Mueller M.
University Wuerzburg, Germany;
[email protected]
Besides the enzymatical production of jasmonates, the free
radical catalyzed oxidation of linolenic acid in plants leads
to the formation of phytoprostanes. Among these
oxylipins, cyclopentenones like OPDA and phytoprostanes
A, B and deoxyJ represent a group of reactive electrophile
substances (RES) with biological activity. In planta, the
production of oxylipins is activated in response to various
stress conditions including wounding, insect and pathogen
attack and is also part of the plant response to these stress
conditions. Transcriptome analyses revealed that OPDA
and phytoprostane A alter the expression of genes related to
detoxification, stress responses and secondary metabolism
as well as the expression of genes related to cell division
and growth. In order to identify differentially expressed
proteins after oxylipin treatment, 2D PAGE analyses were
performed. Containing an α,β-unsaturated carbonyl,
cylopentenone oxylipins represent Michael acceptors which
can spontaneously bind to cellular nucleophiles, including
free thiol and amino groups of peptides and proteins.
Glutathione, the most abundant cellular thiol, rapidly binds
to RES in vitro as well as in planta. Conjugation of
cyclopentenone oxylipins with GSH was measured by
HPLC and LC-MS. Recent studies also indicate that these
oxylipins can regulate the activity of proteins by covalent
binding. To elucidate if OPDA and phytoprostane A exert
their signalling functions in a similar way, we used a
prostaglandin A derivative in comparison to plant oxylipins
for western blot analyses and enzyme activity assays.
P30: 10
PURIFICATION, IDENTIFICATION AND
BIOCHEMICAL CHARACTERIZATION OF
PLASMA MEMBRANE-ASSOCIATED MALATE
DEHYDROGENASES FROM MAIZE (ZEA MAYS
L.) ROOTS
Menckhoff L.1, Buck F.2 and Lüthje S.1
1
Germany; 2University of Hamburg (UKE), Inst.
Zellbiochem Neurobiol,Germany; [email protected]
Malate dehydrogenase (MDH, EC 1.1.1.37) is a wide
spread enzyme in eucaryotic cells which catalyses the
conversion of oxal acetic acid (OAA) and malate by
NAD(P)H. The multimeric enzyme consist of identical
subunits (30 to 35 kD) mainly organised as dimers or
tetramers.
In addition to soluble isoenzymes, membrane-associated
malate dehydrogenases have been described for
peroxisomes, inner mitochondrial membranes, and renal
brush border membranes. Meanwhile, OAA reductase
activity was found with isolated plant plasma membranes
and initial attempts at the purification of these enzymes
(pmMDH) have been published (van Gestelen et al., 1997;
Cordoba-Pedregosa et al., 1998, Lüthje et al, 1998).
In the present work multiple isoenzymes of pmMDH were
purified by dye-ligand affinity and ion exchange
chromatography from plasma membrane fractions of maize
(Zea mays L.) roots. Enzyme kinetics of the partially
purified proteins were characterized in detail (e.g. KM, pHdependence and inhibitors). The data at hand demonstrated
POSTER ABSTRACTS
93
P30
significant differences between pmMDH and soluble
cytosolic MDH isoenzymes. Protein-protein interaction was
investigated by blue native polyacrylamide gel
electrophoresis (BN-PAGE). The type of interaction of
pmMDH with the plasma membrane was analysed by
peptide sequence analysis (ESI-QTof-Ms/Ms, hydropathie
plots, etc.).
P30: 11
Redox signalling function of the chloroplast 2-Cysteine
peroxiredoxin
Roloff N., Laxa M. and Dietz K.
The chloroplast peroxiredoxin, a thiol-based antioxidant,
accumulates to concentrations as high as 100 µM in the
stroma. Upon reaction with peroxide substrate, it undergoes
major conformational changes involving dimer-decamer
transitions. In addition to the enzymatically active thiol
form (decamerred) and the disulfide form (dimer) an
overoxidized sulfinic acid form exists (decamero-ox). The
decamero-ox binds to DNA. The contribution explores this
new feature to bind to DNA of the 2-CysPrx decamero-oxform. DNA-binding of 2-Cys Prx has a high significance
for redox-dependent signalling in organelles. Binding to
DNA was seen in gel shift assays and could be visualized
by atomic force microscopy. DNA binding also affected
DNA-dependent processes. 2-Cys Prx was co-precipitated
with chloroplast DNA. The amount of DNA-associated 2Cys Prx increased in high light-treated chloroplasts. In
addition plants with decreased 2-Cys Prx amounts showed
enhanced transcript accumulation of chloroplast-encoded
genes. Based on these results, a model is proposed that
incorporates the diverse roles of 2-Cys Prx in chloroplast
reactive oxygen defence, redox regulation and signalling.
P30: 12
The redox imbalanced mutants of Arabidopsis thaliana
differentiate redox regulation of chloroplast antioxidant
enzymes from ROS signalling
Hiltscher H., Heiber I., Dietz K. and Baier M.
Universität Bielefeld, Germany; [email protected]
Most chloroplast proteins, including all antioxidant
enzymes, are nuclear encoded. As part of the acclimation
process to photooxidative stress, the expression is induced.
To investigate the signalling pathways involved in
chloroplast-to-nucleus redox communication, a mutant
screen was performed in a chemically mutagenized
Arabidopsis thaliana reporter gene line expressing
luciferase under control of the redox sensitive promoter of
the gene for chloroplast 2-Cys peroxiredoxin A (2CPA).
Five mutants, which were isolated for low 2CPA promoter
activity, show decreased responsiveness of the redox
sensitive promoter elements in the 2CPA promoter. In
addition, the expression of stromal and thylakoid-bound
ascorbate peroxidase, monodehydroascorbate reductase and
CuZn-superoxide dismutase were decreased. However,
marker genes for ROS (reactive oxygen species) signalling
were induced in the mutants at least to the same level as in
wild-type plants. It is concluded that the expression of
chloroplast antioxidant enzymes is regulated by distinct
signalling pathways which differentiate from ROS
signalling known from pathogenesis and wounding
responses. Special attention is given to metabolic signals
94
POSTER ABSTRACTS
and the acceptor availability at photosystem I and their
integration in hormonal signal transduction cascades.
P30: 13
The role of NADP-malate dehydrogenase for redox
homeostasis during photosynthesis
Strodtkötter I., Linke V., Goss T. and Scheibe R.
Department of Plant Physiology, University of Osnabrueck,
Indirect transport of reducing equivalents between cell
compartments is achieved by malate-oxaloacetate shuttles
involving malate dehydrogenases (MDH) for the
interconversions. MDH catalyze the readily reversible
reduction of oxaloacetate to malate using either NADH or
NADPH. Chloroplasts contain the redox-controlled NADPMDH, which is activated in the light and serves as the key
enzyme of the malate valve, balancing the ATP/NADPH
ratio in the chloroplast, since the ATP production continues
while electrons are transferred to malate which in turn will
be
exported.
We
use
knock-out plants
of
Arabidopsis thaliana for NADP-dependent MDH in order
to obtain more insight into the role of the light-activated
NADP-MDH in C3 plants. By this way, alternative
compensatory strategies in NADP-MDH knock-out plants
can be identified which protect the chloroplasts from
photoinhibition under high-light conditions. In another
approach, we generated transgenic plants expressing a
mutated, permanently active NADP-MDH.
P30: 14
Tissue-Specific Expression of Peroxiredoxins in Maize
Oelze M. and Dietz K.
The tropical C4-plant maize has the characteristic Kranz
anatomy with a separation into two different cell types, the
mesophyll and bundle sheath cells, each with different
metabolic functions. Mesophyll cells perform the primary
CO2- fixation and generate NADPH by linear electron
transport involving PS II and I. In contrast bundle sheath
cells comprise the enzymes of the Calvin Cycle and
procure ATP by cyclic electron transport around PSI. Due
to linear electron transport and the water splitting activity
of PSII the production rate of reactive oxygen species
(ROS) is higher in mesophyll than in bundle sheath cells.
Previous studies indicated that components of the
antioxidant defence system like ascorbate peroxidase are
not uniformly distributed among the two cell types. In this
context we investigated the tissue specific localisation of
the peroxiredoxin protein family. Peroxiredoxins are
abundant ubiquitous thiol-based peroxidases, located in
different cell compartments. These low-efficiency
peroxidases are characterized by broad substrate specificity.
In contrast to other antioxidant defence systems their
reaction mechanism is very robust and independent of
sensitive cofactors. It is shown that accumulation of 2-Cys
Prx, Prx Q and PrxIIF proteins differs in a tissue-specific
manner between both specialised cell types. In accordance
with the higher ROS production rate mesophyll cells are
equipped with higher amounts of these antioxidant
enzymes. These data provide first insight into the
peroxiredoxin gene family in C4-plants and their role in
antioxidant defence system.
P31
P31: SECONDARY
METABOLISM
P31: 1
Scent analysis of Tetrapanax papyrifer (Araliaceae)
Wu W.1, Dötterl S.2, Imhof S.1, Weber H.1, Wen J.3 and
Labandeira C.3
1
Philipps University Marburg, Germany; 2University of
Bayreuth, Germany; 3Smithsonian Institution, Washington,
DC, USA; [email protected]
The protandrous and cross-pollinated plant Tetrapanax
papyrifer (Araliaceae) has large inflorescences up to 1 m in
length and 1 m in width, which consist of many green to
yellowish-white flowers with a pleasant odor. An important
feature is the indumentum of the dense, brownish,
multicellular, stellate glandular trichomes, which covers the
epiterranean parts of plant, an adaptation primarily against
herbivores. We sampled the scent of inflorescence and
different floral parts as well as the scent from foliar
glandular
trichomes.
Gas
Chromatography-Mass
Spectrometry was used to analyze the scent collected by
dynamic headspace methods. A total of 75 compounds
were found, mainly sesquiterpenoids (40) and
monoterpenoids (22), but also fatty acid derivatives (6),
benzenoids (4), and nitrogen-bearing compounds (3). The
sesquiterpenes strongly dominated the samples collected
from the glandular trichomes, whereas monoterpenes also
had sources from flowers and floral parts, most of which
were not emitted by the trichomes. Linalool oxide
pyranoid, and linalool oxide furanoid isomers, as well as
linalool, were the principal monoterpenoids emitted from
floral organs. The results indicate that the special features
of floral secretory structure in Tetrapanax papyrifer have
dual functions in being attractive to pollinators (linalool
and its oxides) and protection of floral organs
(sesquiterpenes).
P31: 2
Characterization and homology modelling of a new
plant O methyltransferase from Papaver somniferum
Pienkny S.1, Ziegler J.1,2 and Brandt W.1
1
Leibniz-Institut für Pflanzenbiochemie, Halle, Germany;
2
Department of Biological Sciences; University of Calgary,
Papaver somniferum produces many different alkaloids of
pharmaceutical interest like the narcotic analgetic
morphine, the antitussive narcotic analgetic codeine and the
antibiotic sanguinarine. The diversity of these different
alkaloids is partially due to the modification of the
benzylisoquinoline core structure by O-methyltransferases
(OMTs). The investigation of the differential expression of
ESTs in Papaver somniferum and other Papaver species
led to the identification of a new O-methyltransferase from
P. somniferum. Identification of the full length sequence
showed that this gene shares 68 % homology to the
norcoclaurine-6-O-methyltransferase. To elucidate the
substrate specificity of the enzyme, a homology model was
built based on the x-ray structure of isoflavone-Omethyltransferase of Medicago sativa. Thereafter, docking
experiments with several putative substrate structures
favoured the benzylisoquinoline S-norreticuline. In vitro
activity tests with the enzyme showed very selective
substrate specificity towards S-norreticuline. In further
analyses the kinetic parameters for S-norreticuline and the
cofactor S-adenosyl-L-methionine were determined.This
adds an OMT with a new substrate specificity to the
already known benzylisoquinoline OMTs. To see the
structural basis for recognition of the different substrates,
the binding sites of the four OMTs of P. somniferum shall
be identified by homology modelling and subsequent
docking. The outcome will be used for site-directed
mutagenesis experiments in the new OMT, that may alter
its substrate specificity.
P31: 3
MYB76 and MYB29, Commanders of Glucosinolate
Defence
Engqvist M., Gigolashvili T., Yatusevich R. and Flügge
U.
Botanisches Institut, Universität zu Köln, Germany;
[email protected]
Glucosinolates are amino acid-derived secondary
metabolites, mainly existing in plants of the family
Brassicaceae, that protect the plants against generalist
herbivores and pathogens. Glucosinolate biosynthesis
include amino acid side chain modification, C-terminal
decarboxylation followed by S-glucosylation and Nterminal oxidation followed by sulfation. The most
abundant glucosinolates in Arabidopsis thaliana are
aliphatic and indolic glucosinolates, derived from
methionine and tryptophan, respectively. Many of the
structural genes in glucosinolate biosynthesis are identified,
but little is known about their regulation.We have
characterized two R2R3-MYB transcription factors,
MYB29 and MYB76, from Arabidopsis thaliana, which
activate genes in the aliphatic glucosinolate pathway. Both
genes are most strongly expressed in the plant hypocotyl
but also in leaves and inflorescence nodes, MYB29 is
additionally expressed in roots. External stimuli intended to
simulate herbivore or pathogen attack, such as tissue
wounding or addition of exogenous methyl jasmonate,
greatly induced their expression. MYB76 and MYB29
individually integrate their response by promoting MYB76
transcription and by repressing indolic transcription factor
ATR1/MYB34 and HIG1/MYB51 expression. Increased
levels of MYB76 and MYB29 leads to activation of
aliphatic glucosinolate biosynthetic genes and consequently
to accumulation of aliphatic glucosinolates, thus boosting
the plant defence.Gigolashvili, T., et al. (2007) Plant J. 23
[Epub ahead of print]
P31: 4
1-Deoxy-D-xylulose 5-phosphate synthase isogenes and
their role in isoprenoid biosynthesis of tomato
Paetzold H., Strack D. and Walter M.
Leibniz Institute of Plant Biochemistry, Halle (Saale),
All isoprenoids derive from the common precursor
isopentenyl diphosphate and its isomer dimethylallyl
diphosphate, synthesized either via the cytosolic
mevalonate or via the plastidial methylerythritol phosphate
(MEP)-pathway. The first step of the MEP-pathway is
catalyzed by 1-deoxy-d-xylulose 5-phosphate synthase
(DXS) generating 1-deoxy-d-xylulose 5-phosphate from
glyceraldehyde 3-phosphate and pyruvate. At least two
isoenzymes of DXS were found in plants (DXS1 & DXS2;
Walter et al., The Plant Journal, 31, 243-254, 2002). Both
proteins share a sequence identity of about 70 percent. In
POSTER ABSTRACTS
95
P31
this work we focused on DXS1 and DXS2 from tomato.
Only transcripts of DXS1 are found in ripening fruits.
However, transcripts of both genes could be detected in
leaves which might be due to the presence of trichomes,
producing mono- and diterpenes). Trichome isolation
experiments followed by RT-PCR analyzes demonstrated
that DXS2 transcripts accumulate to higher levels in these
organs as compared to DXS1. To get more insights into
differential occurrence of both isoenzymes, their
localization is being investigated with specific antibodies.
Antibodies against peptides from DXS1 and DXS2, raised
in rat and rabbit, were tested against total protein extracts
from different organs of tomato. Currently functional
analysis and transgenic approaches to suppress DXS2
expression are in progress. In order to investigate the
regulation of both genes promoter analyses will be
performed.
P31: 5
Biochemical and structural analysis of substrate specific
and promiscuous Mg2+-dependent Omethyltransferases
Kopycki J.1, Rauh D.1,3, Vogt T.2 and Stubbs M.1
1
Institut für Biotechnologie : Martin-Luther-Universität
Halle-Wittenberg; 2Leibniz-Institute of Plant Biochemistry,
Department of Secondary Metabolism; 3current address
Chemical Genomics Centre of the Max Planck
Society,Dortmund; [email protected]
Methylated hydroxyl groups are found in many naturally
occurring compounds in nature. The enzymes responsible
for this biological methylation are usually S-adenosyl-Lmethionine (AdoMet) dependent O-methyltransferases
(OMTs). In this group a subset of bivalent cation dependent
enzymes can be distinguished that exhibit activity towards
compounds containing an aromatic vicinal dihydroxy
system. Among the most prominent representatives of this
subset in plants are the caffeoyl CoA OMT (CCoAOMT),
involved in lignin biosynthesis, and catechol OMT in
animals. We present a novel plant-derived enzyme, a cation
dependent OMT from Mesembryanthemum crystallinum.
The three dimensional structure of this enzyme, which
exhibits a broad substrate specificity when compared to
Caffeoyl CCoAOMT, suggest that two major regions
determine the substrate specificity in those proteins: the Nterminal residues and a loop towards the C-terminus. These
regions also display the lowest degree of sequence
similarity among the the members of AdoMet dependent
enzyme subclusters. We have created chimeric enzymes
between CCoAOMT and M. crystallinum OMT using sitedirected mutagenesis and domain exchange and studied
their substrate preferences. Our results indicate that the
observed substrate specificity in vitro is influenced by
relatively small changes in otherwise conserved regions.
P31: 6
Biochemical characterisation of flavonol synthesis in
Preuß A.1, Sagasser M.2, Stracke R.2, Weishaar B.2,
Matern U.1 and Martens S.1
1
Philipps- Universität Marburg, Inst. f. Pharmazeutische
Biologie, Germany; 2Universität Bielefeld, Fakultät
Biologie, LS für Genomforschung, Germany;
[email protected]
Flavonol synthase (FLS) was initially reported from
irradiated parsley cells as a soluble dioxygenase (2-ODD)
96
POSTER ABSTRACTS
requiring 2-oxoglutarate and ferrous iron and to specifically
convert dihydroflavonols to flavonols. Recent results
indicate that FLS and the closely related anthocyanidine
synthase (ANS) are bi- and multifunctional proteins
utilizing various flavonoid precursors. In this context ANS
was found to catalyze a FLS-like reaction in vitro, which
may present an alternative route to flavonols in vivo, but
final proof of this hypothesis is missing. Five cDNAs
coding for putative FLSs and one ANS were isolated from
Arabidopsis thaliana and heterologously expressed. The
catalytical properties of the recombinant proteins were
studied by enzyme assays and by bioconversion of potential
precursors. Only one of the recombinant FLSs (AT_FLS1)
showed clear activity in both systems converting
flavanones and dihydroflavonols to the corresponding
flavonols. For the remaining FLS proteins no activity was
detected, but the recombinant AT_ANS shows beside
others clear FLS-like activity with various substrates.
Protein preparations from plant tissue of Arabidopsis
wildtype (Col-0) showed clear FLS activity, whereas in
corresponding tissue from the mutant lines (e.g. FLS1mutant) no formation of flavonols was detected. However,
the mutant lines still accumulate detectable amounts of
quercetin
and
isorhamnetin
glycosides,
further
corroborating a potential role of ANS in the formation of
flavonols. Final confirmation of this hypothesis will be
obtained by analysis of an FLS1/ANS double mutant lines.
P31: 7
Biochemical characterization of flavone biosynthesis in
Equisetum arvensis
Hundt M., von Thülen A., Matern U. and Martens S.
Philipps-Universität Marburg, Institut für Pharmazeutische
Biologie, German; [email protected]
Equisetum arvense L. (Equisetaceae - horsetail) is a well
known and widespread pteridophyte. Its sterile stems are
used as phytomedicines in various countries. Horsetail
preparations have effects on diuresis and possess
antioxidant and germination inhibitory activity. Sprouts of
E. arvense are known to accumulate various flavonoids. In
addition to the widespread flavones apigenin/luteolin and
flavonols kaempferol/quercetin derivatives of the rare
protoflavone protogenkwanin were identified. Using
standard enzyme preparation and radioassays, activity for
flavonoid enzymes are investigated to understand the
formation of the various compounds. Chalcone synthase
activity, a key enzyme in flavonoid biosynthesis, was
detected in all tissue stages used. When naringenin was
applied as a substrate in a dioxygenase assay two novel
products were detected after autoradiography. These
products were preliminary identified as apigenin and
kaempferol by co-chromatography in different solvent
systems. These findings led to the assumption that in
horsetail in addition to the common enzymes flavanone 3ßhydroxylase and flavonol synthase a flavone synthase I
(FNS I) is responsible for the formation of flavones. Using
monooxygenase assay condition no product formation was
detectable. Up to now FNS I was only described for
members of Apiaceae and all other families were
considered to express the cytochrome P450 type FNS II.
The described activity of a FNS I in E. arvense will be of
enormous interest in the context of the evolution of flavone
synthesis in plant kingdom.
P31
P31: 8
BIOCHEMISTRY AND cDNA CLONING OF
ANTHRANILATE N-METHYLTRANSFERASE
FROM RUTA GRAVEOLENS L.
Rohde B., Hans J. and Matern U.
Institut für Pharmazeutische Biologie, Philipps Universität
Marburg, German; [email protected]
Acridone alkaloids are a small group of secondary
metabolites produced mainly by plants of the Rutaceae
family and are considered to serve as phytoalexins in the
defense against pathogens. The biosynthesis of acridones
branches from primary metabolism by the N-methylation of
anthranilate,
and
the
relevant
S-Adenosyl-Lmethionine:anthranilate N-methyltransferase (ANMT) was
purified to apparent homogeneity from elicitied Ruta
graveolens cell cultures and partially sequenced for cDNA
cloning. The translated polypeptide revealed homology to
class II caffeate O-methyltransferases and little similarity to
carboxyl- or N-methyltransferases, but the recombinantly
expressed enzyme showed exclusive specifity for
anthranilate with high affinity. Most notably, a Glu residue
strictly conserved in class II OMTs (Glu297 in alfalf
COMT) was replaced by Asn298 in ANMT, and
Asn298Glu-mutagenesis drastically reduced the ANMT
activity, which sheds light on the functional shift during
evolution. A polyclonal ANMT antiserum was raised in
rabbits, and western blotting revealed the constitutive
expression of the enzyme in cultured Ruta graveolens cells,
which nevertheless transiently increased about 2.5-fold
upon the addition of fungal elicitor. As anthranilate is an
essential precursor for L-tryptophan biosynthesis,
overexpression of ANMT in plants other than Rutaceae
may shunt anthranilate to secondary products and would
allow studies on tryptophan and indole biosynthetic
regulation.
P31: 9
Biosynthesis of Retinoids in Cyanobacteria
Scherzinger D.1, Ruch S.1, Kloer D.2 and Al-Babili S.1
1
University of Freiburg, Faculty of Biology, Cell Biology,
Freiburg, Germany; 2NIDDK, NIH, DHHS, Laboratory of
Molecular Biology, Bethesda, USA;
[email protected]
Retinoids
are
carotenoid
derived
compounds,
apocarotenoids, which fullfill essential functions in many
biological systems. For instance, retinal represents the
chromophore of the ubiquitous opsins which sense light
and act as ion-pumps. In animals, retinal is formed through
the symmetrical cleavage of β-carotene catalyzed by the βcarotene oxygenase I (BCO I), a member of the carotenoid
oxygenase family. Using in vitro assays, we identified
cyanobacterial enzymes exhibiting a novel retinal forming
activity. The Apocarotenoid Cleavage Oxygenases (ACOs)
SynACO (Synechocystis PCC6803) and NosACO (Nostoc
PCC7120) catalyze the cleavage of a wide variety of
apocarotenoids, different in chainlength (C25-C35) and
functional groups, into retinal (C20) and retinal-like
compounds. In contrast to BCO I, both cyanobacterial
enzymes do not convert β-carotene. As the first member of
the carotenoid oxygenase family, the crystal structure of
SynACO was recently solved at 2.4 Å resolution, revealing
the reaction center geometry. Interstingly, all sequenced
cyanobacterial genomes reveal at least one gene with
striking similarity to NosACO and SynACO indicating
their biological relevance. To elucidate the function of
retinoids in cyanobacteria, expression analyses of NosACO
and SynACO were performed under different physiological
conditions. Our preliminary data show that the expression
of both genes is induced by cold stress and under high light
conditions indicating a role of retinoids in the stress
response. Further analyses are now performed using a
ΔSynACO-Synechocystis strain.
P31: 10
Calystegines – tropane alkaloids in Brassicaceae
Draeger B., Brock A., Richter U., Kaiser H., Teuber M.,
Meier A., Biastoff S. and Jockovic N.
Martin Luther University, Germany;
[email protected]
Calystegines are non-esterified nortropane alkaloids with
three to five hydroxyl groups in various positions1. The
compounds were initially described in Calystegia sepium
(hedge bindweed), Convolvulaceae. They occur in all
Solanaceae renown for medicinal tropane alkaloids, e.g.
atropine and scopolamine and in many other Solanaceae
such as potato or tomato. Calystegines were also identified
in Moraceae and in Erythroxylaceae, where tropane
alkaloids like cocaine are formed. Surprisingly, many
Brassicaceae
contain
considerable
amounts
of
calystegines2. Within Brassicaceae, calystegines were not
identified in Arabidopsis thaliana, but in Cochlearia
species, in Capsella bursa-pastoris, and in several other
species.
Calystegine biosynthesis in Solanaceae comprises
enzymatic steps that are known from the biogenesis of
medicinal tropane alkaloids, e. g. methylation of putrescine
and reduction of tropinone. Genes of the corresponding
enzymes were cloned from calystegine forming
Solanaceae, and enzyme proteins were expressed. Catalytic
characteristics and subcellular localisation of the enzymes
were investigated. Assuming that calystegine formation in
Brassicaceae may follow a similar biosynthetic route like in
Solanaceae, tropinone reductase-like sequences were
cloned and expressed from Brassicaceae. One enzyme from
Cochlearia officinalis was able to reduce tropinone and to
yield both, tropine and pseudotropine.
P31: 12
Characterisation of the polyphenol oxidase multigene
family from Physcomitrella patens
Richter H., Lieberei R. and von Schwartzenberg K.
Biocenter Klein Flottbek, Germany;
[email protected]
Polyphenol oxidising enzymes (PPOs) and their encoding
genes have been characterised for many seed plants; their
exact function in plants is still discussed. Previously we
reported on a PPO encoding gene from the ancient land
plant Physcomitrella patens, Pp_PPO1. Here we report on
12 members of the PPO gene family from Physcomitrella.
Bioinformatic characterisation of the gene family members
revealed PPOs to be assembled in 5 groups with 2-3 PPOs
each. PPOs within one group show similar hydophobicity
properties and mostly the same predicted subcellular
localisation. Four of the analysed PPO genes contain no
intron while the other 8 have an intron (79-224 nts) at the
same corresponding positions. Homology among the 12
PPOs ranged from 73-33%; PPO1 and 2 show the highest
degree of homology to seed plant PPOs (27-32%). The
expression of each PPO gene was determined by RT-PCR.
Ten of the 12 analysed PPO genes were found to be
expressed in protonema. Localisation studies focused on
PPO1, which is bioinformatically predicted to enter the
POSTER ABSTRACTS
97
P31
secretory pathway. Transient expression of GFP-fusion
proteins showed strong intracellular fluorescence only if
the PPO1 signal sequence was not present. Complete
coding sequence fused to GFP resulted in little intracellular
fluorescence pointing towards extracellular targeting.
PPO1-knockout experiments so far revealed gene
replacement only for diploid heterozygous plants. Haploid
plants showed exclusively insertional recombination
leaving the PPO1 coding sequence intact. Further
experiments aiming to knockdown the PPO gene family are
under way.
P31: 13
Characterization of Carotenoid Oxygenases from Oryza
sativa
Alder A. and Ilg A.
Universität Freiburg, Germany; [email protected]
Carotenoids are precursors of several compounds,
apocarotenoids, exerting essential functions, e.g. the
ubiquitous chromophore retinal, the phytohormone abscisic
acid (ABA) and the fungal pheromone trisporic acid. In
addition, characterization of A. thaliana mutants suggest
that yet unidentified carotenoid-derivatives are required for
normal shoot branching. In general, apocarotenoids are
synthesized through oxidative cleavage, a reaction
catalyzed by the carotenoid oxygenase family which is
represented in all taxa. The genome of O. sativa encodes at
least thirteen members of the carotenoid oxygenase family.
Based on sequence homology, rice carotenoid oxygenases
can be divided into two groups. The first one consists of
enzymes with close homologs in A. thaliana including
MAX4 and MAX3 which produce β-apo-13-carotenone, an
C18-apocarotenoid involved in the establishing of the apical
dominance. Results obtained from in vitro-characterization
of the MAX4 homolog RDF from rice indicate that the
latter is a true ortholog of the former. RDF mediates the
synthesis of the β-apo-13-carotenone from β-apo-10ćarotinal, the substrate converted by MAX4. The second
group of carotenoid oxygenases seems to be rather rice
specific. It includes the three enzymes RDA, RDB and
RDG. Our preliminary data suggest that RDA catalyzes the
formation of a 3-OH-C18-carotenone from the synthetic
substrate 3-OH-β-apo-10´-carotinal. In vitro assays are now
performed to identify other RDA-substrates. To elucidate
the functions of RDF and RDA in planta, RNAi
experiments are now carried out.
P31: 14
Characterization of rosmarinic acid biosynthesis in cell
cultures of Melissa officinalis (Lamiaceae)
Weitzel C. and Petersen M.
Philipps-Universität Marburg, Germany;
[email protected]
Melissa officinalis L. (Lamiaceae) has been used in many
practical applications in medical science, because of its
antibacterial, sedative and slight spasmodic effects.
Extracts of Melissa officinalis have antiviral activity
against a variety of viruses, including Herpes simplex virus
(HSV) and HIV-1. The activity has been attributed to
caffeic acid and its derivates, e.g. rosmarinic acid, as well
as to tannins [1].
Rosmarinic acid (RA), an ester of caffeic acid and 3,4dihydroxyphenyllactic acid, is a plant secondary metabolite
belonging to the class of hydroxycinnamic acid esters. The
biosynthesis starts with two parallel pathways beginning
98
POSTER ABSTRACTS
with phenylalanine and tyrosine and totally consists of only
eight enzymes [2] which have been characterized in cell
cultures of Coleus blumei Benth. Since C. blumei is
amphitetraploid, expression studies are difficult to interpret.
Therefore the characterization has to be repeated in cell
cultures of Melissa officinalis, a diploid plant. Additionally
the corresponding genes will be cloned from Melissa and
compared to the known genes in Coleus blumei.
References:
[1] Wölbling RH, Leonhardt, K (1994) Local therapy of
herpes simplex with dried extracts from Melissa officinalis.
Phytomedicine 1: 25-31
P31: 15
Effects of phytoestrogen extracts from Linum
usitatissimum on the human mamma carcinoma cell
line MCF 7
Szewczyk M.1, Abarzua S.1, Richter D.3, Schlichting A.4,
Ruth W.2, Briese V.3 and Piechulla B.1
1
University of Rostock, Institute of Biological Sciences,
Germany; 2University of Rostock, Institute of Technical
Chemistry, Germany; 3University of Rostock, Department
of Obstetrics and Gynaecology, Germany; 4SteinbeisTransfercenter, Soil Biotechnology, Groß Lüsewitz,
Phytoestrogens are a diverse group of nonsteroidal
compounds synthesized in the plant secondary metabolism.
The potential of phytoestrogens to reduce tumour growth
has been described in several studies. In this study the
effect of phytoestrogen extracts from different plant organs
of the flax species, Linum usitatissimum, on cytotoxicity,
cell proliferation and cell vitality in a human mamma
carcinoma cell line was tested. Phytoestrogen extracts from
stems, leaves and roots of L. usitatissimum were prepared
using a modified method of Luyengi et al. (1996). The
extract compounds were analysed by Pyrolysis Field
Ionization Mass Spectrometry (PFI-MS) and HPLC-MS.
Cell proliferation and vitality of MCF 7 cells were
significantly affected by the phytoestrogen extracts of L.
usitatissimum. Root extracts significantly inhibited the cell
growth, especially at high concentrations. PFI-MS analysis
revealed that flax root extracts are composed of higher
amounts of phenols and lignans than stem and leaf extracts.
HPLC-MS analysis demonstrated that the root, stem and
leaf extracts of L. usitatissimum contained more
representatives of lignans compared to isoflavones. It is
suggested that potential phytoestrogens synthesized in flax
roots could have beneficial effects for the prevention of
hormone-dependent tumours.
P31: 16
Evaluation of Chlorella sp. secondary metabolites on
Antimicrobial and Antioxidant Activity
Yılmaz Köz F.1, Demirel Z.2, Karabay Yavaşoğlu N.2,
Ozdemir G.2 and Conk Dalay M.3
1
Ege University, Faculty of Pharmacy,Dep. of Pharm.
Microbiology,Turkey; 2Ege University, Faculty of Science,
Dep.of Biology,Turkey; 3Ege University, Faculty of
Engineering, Dep.of Bioengineering, Turkey;
[email protected]
The aim of the present study was to investigate
antimicrobial and antioxidant secondary metabolites of
green microalgae Chlorella sp. obtained from Ege
University Micro Algae Culture Collection. Chlorella sp.
was cultivated under the optimum conditions in laboratory.
After harvesting the cells were freeze-dried and extracted in
P31
methanol, ethanol, chloroform, acetone, dichloromethane,
hexane by a soxhlet apparatus. Dry material was also
subjected steam-distillation by a Clevenger type apparatus
and the obtained components were investigated by GC,
GC/MS. Nitric acid, 2-methylpropyl ester (51.11 %) and
phytol (29.84 %) were found as major components.
Antimicrobial tests were carried out by using disc diffusion
method against gram-positive and gram-negative bacterial
strains including two specific pathogens, methicillinoxacillin resistant Staphylococus aureus ATCC 43300,
hemorrhagic Escherichia coli (O157:H7) RSSK 232 and
one yeast strain Candida albicans ATCC 10239. Solvent
extracts showed remarkable antibacterial activity,
nevertheless, the volatile components have not found
antimicrobially active. Antioxidant activity was determined
by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical
scavenging assay, beta carotene bleaching assay, and
measuring total phenolic content by Folin–Ciocalteu
reagent. Chlorella has long been known as a potential
source of food and energy because of high in protein and
other essential nutrients. According to this study, its
secondary metabolites could be also considered valuable
products for pharmaceuticals and cosmetics.
P31: 17
Evolution of flavone synthase I from parsley flavanone
3ß-hydroxylase by site-directed mutagenesis
Martens S., Gebhardt Y. and Matern U.
Philipps Universität Marburg, Germany;
[email protected]
Flavanone 3ß-hydroxylase (FHT) and flavone synthase I
(FNS I) are 2-oxoglutarate-dependent dioxygenases with
80% sequence identity which catalyze distinct reactions in
flavonoid biosynthesis. However, FNS I has been reported
exclusively from few Apiaceae species while FHTs are
more abundant. Domain swapping experiments joining the
N-terminus of parsley FHT with the C-terminus of parsley
FNS I and vice versa revealed that the C-terminal portion is
not essential for FNS I activity. Sequence alignments
identified 26 amino acid substitutions conserved in FHT vs.
FNS I genes. Homology modelling based on the related
anthocyanidin synthase structure assigned seven of these
amino acids to the active site. Accordingly, FHT was
modified by site-directed mutagenesis creating mutants
encoding from one to seven substitutions, which were
expressed in yeast for FNS I and FHT assays. The
exchange I131F in combination with either M106T and
D195E or L215V and K216R replacements was sufficient
to confer some FNS I side activity. Introduction of all
seven FNS I substitutions into the FHT sequence, however,
caused a nearly complete change in enzyme activity from
FHT to FNS I. Both FHT and FNS I were proposed to
initially withdraw the ‘ß-face’-configurated hydrogen from
carbon-3 of the naringenin substrate. Our results
demonstrate that the 7-fold substitution affects the
orientation of the substrate in the active site pocket such
that this is followed by syn-elimination of hydrogen from
carbon-2 (FNS I reaction) rather than the rebound
hydroxylation of carbon-3 (FHT reaction).
P31: 18
Genomic, proteomic and metabolomic studies on
terpenoid and flavonoid biosynthesis in sunflower
glandular trichomes
Göpfert J. and Otmar S.
Universität Hohenheim, Institut für Botanik, Germany;
[email protected]
Asteraceae are known to secrete flavonoids and bioactive
terpenoids in capitate glandular trichomes of leaves and
inflorescence. The size and progressive development of the
capitulum makes Helianthus annuus an ideal model to
study biosynthesis of these metabolites in trichomes from
pre- to postsecretory stages.
Trichomes from anther appendages were detached and
analysed microscopically. Blue fluorescence was observed
in the secreted metabolites and attributed to 5deoxynevadensin, a flavone-type rarely found in
Asteraceae. Metabolic profiling of trichomes in consecutive
developmental stages revealed parallel sequestration of the
flavonoid and various sesquiterpene lactones. Results from
microscopy and HPLC analyses allowed exact
determination of the biosynthetically active trichome
stages. RNA transcripts from pure trichome showed early
expression of PAL, whereas chalcone synthase activity was
upregulated in a later secretory stage. Two germacrene
synthases (TPS), involved in sunflower sesquiterpene
biosynthesis, were traced in cDNA expression patterns of
trichome
cells.
This
enabled
sequencing
and
characterization of these genes. Semiquantitative RT-PCR
showed highly regulated gene expression for both enzymes
which differed from genes involved in sesquiterpene
precursor biosynthesis. A sunflower trichome EST library
was screened for candidate genes of enzymes with a
potential function in modification of the sesquiterpene
skeleton. Together with the TPS genes, the enzymatic
function of these genes was evaluated in vivo using
genetically engineered yeast strains.
P31: 19
Heterologous expression and characterisation of
progesterone 5β-reductase, a key enzyme in cardenolide
biosynthesis, from cardenolide-free Arabidopsis
thaliana
Kreis W., Herl V., Gabriele F. and Frieder M.
FAU Erlangen-Nürnberg, Germany; [email protected]
As progesterone 5β-reductase (5βPOR) has so far only been
detected in cardenolide-producing plants like Digitalis and
Isoplexis species, the enzyme was supposed to play a key
role in cardenolide biosynthesis. During cardenolide
formation 5βPOR catalyses the conversion of progesterone
to 5β-pregnane-3,20-dione, representing the first stereospecific step in cardenolide biosynthesis. GenBank
searches and alignments using described sequences from
Digitalis lanata and Isoplexis canariensis directed our
attention to a putative protein described for A. thaliana
sharing high homology with the known 5βPORs. Using
specific primers we isolated a cDNA clone from A. thaliana
leaves encoding a putative 5βPOR (At5β-StR). The ORF of
At5β-StR was 1167 nucleotides corresponding to 388
amino acids. Over-expression of a His-tagged fusion At5βStR protein (pQAt5β-StR) was achieved in E. coli using the
pQE expression vector system (Qiagen, Hilden, Germany).
The pQAt5β-StR was purified on a Ni-NTA matrix, its
molecular mass was about 45 kDa as determined by SDSPAGE. The pQAt5β-StR was enzymatically active,
catalysing the stereospecific reduction of progesterone
yielding 5β-pregnane-3,20-dione. Other steroid compounds
were also accepted as substrates. NADPH was the only cosubstrate accepted. Kinetic data of pQAt5β-StR were
scored and will be presented. As A. thaliana lacks
cardenolides our results raise the question whether
progesterone 5β-reductase is involved in metabolic
pathways others than cardenolide biosynthesis.
POSTER ABSTRACTS
99
P31
P31: 20
How are toxic benzophenanthridine alkaloids managed
by the producing cell ?
Vogel M., Schumann B., Sippl W. and Roos W.
University of Halle, Institute of Pharmacy, Lab of
Molecular Cell Biology; [email protected]
The ability of plants to protect the producing cells from
intoxication by their secondary metabolites is an
essential achievement required for the evolutionary success
of phytoalexins. Benzophenanthrine alkaloids are among
the strongest plant-made antimicrobials, due to their
intercalation into ds DNA, inhibition of membrane
potential dependent enzymes, complexing of glutathione
etc.
In cultured cells of the California Poppy (Eschscholzia
californica), the elicitor-triggered overproduction of
benzophenanthridines leads to their excretion into the
apoplast. The external alkaloids, preferentially the most
cytotoxic sanguinarine, undergo a recycling that includes
rapid re-uptake, reduction to less toxic dihydro-alkaloids,
derivatization and re-export. This recycling allows to
present the phytoalexin sanguinarine at the cellular surface
without taking the risk of injuring the living cytoplasm.
Uptake is driven by sanguinarine reductase, a novel,
cytoplasmic enzyme discovered and cloned in our
laboratory. Compared to homologous proteins from
Arabidopsis and Oryza, sanguinarine reductase contains
specific sequence motifs that likely explain its high
substrate specificity and catalytic efficiency, as predicted
by homology modeling.
P31: 21
Hydrolysis of Sinapine is catalyzed by a GDSL-Lipase
like Enzyme
Clauß K., Baumert A., Milkowski C. and Strack D.
Leibniz Institute of Plant Biochemistry, Germany;
[email protected]
Members of the Brassicaceae accumulate sinapate esters
with sinapoylcholine (sinapine) and sinapoylmalate as
major compounds. Sinapine is a characteristic seed
component found mainly in the embryo and sinapoylmalate
in the cotyledons of the seedling. During early stages of
seed germination sinapine is hydrolyzed to sinapate and
choline by an esterase activity (SCE). The enzyme has been
described biochemically1, but the protein structure and the
corresponding gene have not been characterized. Based on
enzyme purification from germinating seeds of oilseed rape
(Brassica napus), peptide sequences of SCE were
generated and used to clone a full-length cDNA.
Heterologous expression of this cDNA in Nicotiana
benthamiana conferred SCE activity to the leaf protein
extract. Sequence analysis of the purified oilseed rape SCE
reveals homology of the protein with a newly described
group of GDSL lipases of Arabidopsis giving rise to the
hypothesis that SCE has been recruited from lipolytic
enzymes of primary metabolism in the course of evolution.
Further biochemical experiments indicate that the SCE has
broad substrate specificity towards choline esters including
phosphatidylcholine. Future work includes promoter
analyses, studies on gene expression and protein
localization as well as evaluation of the evolution of this
lipase-like enzyme family.
1
Strack, D., Nurmann, G. and Sachs, G. (1980) Sinapine
esterase. Part II. Specificity and change of sinapine esterase
100 POSTER ABSTRACTS
activity during germination of Raphanus sativus. Z.
Naturforsch. 35c, 963-966.
P31: 22
Hyperforin Biosynthesis: cDNA Cloning of
Isobutyrophenone Synthase
William M.
Institut für pharmazeutische Biologie TU-Braunschweig,
Pharmaceutical preparations of Hypericum perforatum (St.
John´s Wort) (Clusiaceae) are used for the treatment of
mild to moderate depression. This effect is mainly due to
hyperforin. The biosynthesis of this polyprenylated
acylphloroglucinol derivative starts with the condensation
of isobutyryl-CoA with three malonyl-CoAs, catalysed by
isobutyrophenone synthase (BUS), a type III polyketide
synthase (PKS III). The resulting linear intermediate
undergoes intramolecular Claisen condensation to yield
phlorisobutyrophenone, the hyperforin skeleton. Other
members of the PKS III family are chalcone synthase
(CHS) and benzophenone synthase (BPS). They catalyse
the formation of naringenin chalcone (flavonoid
biosynthesis)
and
phlorbenzophenone
(xanthone
biosynthesis), respectively. Their starter substrates are 4coumaroyl-CoA (CHS) and benzoyl-CoA (BPS). cDNAs
encoding BPS and CHS from Hypericum species have been
cloned previously in our laboratory. The aim of the present
work is cDNA cloning of BUS. Adhyperforin-producing
cell cultures and intact plants of H. calycinum served for
isolation and reverse transcription of poly(A+) mRNA.
Degenerate primers were designed that match to conserved
motives of known PKS III sequences. PCR with
combinations of these primers led to the amplification of
four new cDNA fragments that show 79-90% identity to
known PKS III sequences and are promising candidates to
encode BUS. 3´ and 5´ RACE PCR are in progress to
amplify the missing cDNA ends. The resulting ORFs will
be heterologously expressed in E. coli and characterised.
P31: 23
Immunochemical studies of polyketide synthases from
Hypericum perforatum
Belkheir A. and Beerhues L.
Institute of Phamaceutical Biology,TU Braunschweig,
All pharmacologically active constituents of the wellknown medicinal plant Hypericum perforatum (St. John’s
wort; Clusiaceae) are derivatives of polyketide metabolism.
Two type III polyketide synthases (PKSs) involved are
benzophenone synthase (BPS) and chalcone synthase
(CHS). cDNAs encoding these PKSs were cloned and
characterized. Both enzymes were heterologously
expressed in E. coli as 6xHis-tagged proteins and GSTfusion proteins. Polyclonal antibodies were raised against
the 6xHis-tagged PKSs in rabbits and the IgG fractions
were isolated. The specificity of the antibodies was
examined using immunoblotting following SDS-PAGE.
Anti 6xHis-BPS detected GST-BPS but anti 6xHis-CHS
did not. Conversely, anti 6xHis-CHS stained GST-CHS
whereas anti 6xHis-BPS gave only a poor immunoreaction.
No immunoreactions were found in the presence of the
preimmune IgG preparations. The negligible crossreactivities were confirmed by dot blotting with decreasing
amounts of the GST-fusion proteins that were stained with
anti 6xHis-CHS and anti 6xHis-BPS. In protein crude
extracts from H. perforatum leaves, anti 6xHis-CHS
P31
stained a protein band at a molecular mass of 43 kDa which
corresponds to a CHS subunit. The preimmune IgG failed
to stain this band. During leaf development, maximum
CHS amounts were immunodetected in 0.3-0.5 cm long
leaves. In contrast, BPS was not found at any
developmental stage. In addition, no induction of BPS was
observed after treatment with elicitors such as methyl
jasmonate and salicylic acid. BPS, however, was detected
in roots, whereas flowers contained only CHS.
P31: 24
in situ localisation of enzymes of pyrrolizidine alkaloid
biosynthesis
Enß D. and Ober D.
Botanisches Institut der CAU-Kiel, Germany;
[email protected]
Pyrrolizidine alkaloids (PAs) are a typical group of plant
secondary compounds. They are constitutively produced by
various plant species as a defence against herbivores.
Structurally PAs are ester alkaloids composed of a necine
base and a necic acid. In our group we focus on the
enzymes which are involved in PA biosynthesis. The
transformation from spermidine to homospermidine,
catalysed by homospermidine synthase (HSS), is the first
step in necine base biosynthesis. We assume that for
transformation of homospermidine to the cyclic necine base
a diamine oxidase (DAO) is involved. Three different
cDNAs of DAOs were identified from Senecio vernalis.
One or more of these sequences might encode a DAO that
is involved in necine base biosynthesis. In order to locate
the respective mRNAs in plants we established in situ
hybridization in our group. After localizing HSS in Senecio
jacobaea as a control the three different DAOs will be
detected in Senecio vernalis. A colocalisation of mRNAs
encoding HSS and of one or more DAOs would support the
assumption that PA biosynthesis is restricted to specialized
cells.
P31: 25
Phenolic contents, antibacterial activity and antioxidant
capacity of Petalonia fascia collected from around
Aegaen Sea
DEMIREL Z.1, YILMAZ KOZ F.2, KARABAY
YAVASOGLU N.1, OZDEMIR G.1 and SUKATAR A.1
1
Ege University, Faculty of Science, Department of
Biology,Izmir, Turkey; 2Ege University, Faculty of
Pharmacy, Izmir, Turkey; [email protected]
Macroalgae are widely used as food additives. In this study,
it has evaluated the antioxidant capacity and antibacterial
activity of water, methanol, methanol/water, chloroform
extracts of Petalonia fascia, a brown algae (Phaeophyta).
Phenols, a major group of antioxidant phytochemicals,
have profound importance due to their biological and free
radical scavenging activities. Since phenolic compounds
have high antioxidant potential, the antioxidant potency of
P. fascia extracts were investigated by employing various
established in vitro systems. Antioxidant activity of P.
fascia extracts were determined using the procedures of
inhibition of β-carotene bleaching, scavenging of 1,1diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azinobis 3-ethyl benzothiazoline-6-sulfuric acid (ABTS+)
methods. Total phenolic content (TPC) was determined
using Folin-Ciocalteu's procedure. The antimicrobial
activities of P. fascia extracts were evaluated by the disc
diffusion method. The antibacterial activities of the extracts
were reported against spesific strains, methicillin-oxacilin
resistant Staphylococcus aureus ATCC 43300, Escherichia
coli O157:H7 RSSK 232 and Gram (+) and Gram (-)
bacteria. Consequently, it was found that P. fascia contains
many phenolic compounds and P. fascia exerts
antibacterial activities against some strains. Also, P. fascia
was extracted by steam distillation and volatile components
were analyzed using GC and GC-MS.
P31: 26
Physiological and biochemical characterisation of the
plant response to two allelopathic active agents
Zirr K. and Bergmann H.
Friedrich-Schiller-Universität-Jena, Germany;
[email protected]
To analyse the bio-bio-interactions of the two grass species
Arrhenatherum elatius (tall oat grass) and Elytrigia repens
(couch grass) with special regard to allelopathic relations a
greenhouse experiment was done. The high allelopathic
potential of E. repens is known for a long time. Among the
allelopathic substances identified for E. repens ferulic acid
and DIBOA (2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one)
or rather its spontaneous daughter product BOA
(benzoxazolin-2(3H)-one) were especially effective.
The influence of these two active agents ferulic acid and
BOA on A. elatius and on E. repens was examined. Since
different environmental factors can affect the plants
tolerance of allelochemicals, in addition the substrate
moisture as growth factor was varied. The plant response to
the active agents was analysed at the level of the element
uptake as well as on the morphological level (biomass
formation) and the biochemical level (free proline content,
activity of the enzyme superoxide dismutase).
Thus a dose-specific influence of the active agents ferulic
acid and BOA on the two grass species resulted: Small
active agent doses (0.1 mM of ferulic acid and 0.01 mM
BOA) improved the growth of both grass species and
weakened drought stress effects; high active agent doses
(1 mM and 10 mM of ferulic acid or 0.1 mM and 1 mM
BOA) reduced the growth of both grass species and
strengthened the drought stress effects on A. elatius and E.
repens causing a stress-like increase in proline
accumulation.
P31: 27
PRENYLATION REACTIONS IN HYPERFORIN
BIOSYNTHESIS
Kühle S. and Beerhues L.
Institute of Pharmaceutical Biology, TU- Braunschweig,
Hypericum perforatum (St. John’s wort) is one of the best
studied medicinal plants. Its extracts are widely used to
medicate mild and moderate depression. The antidepressant
activity is mainly attributed to the constituent hyperforin
which serves as a broad-band neurotransmitter reuptake
inhibitor. Hyperforin is a bicyclic polyprenylated
acylphloroglucinol derivative. Little is known about its
biosynthesis. Cell cultures of the related species H.
calycinum were found to form hyperforins, thus providing a
valuable in vitro system for biochemical studies. The
hyperforin skeleton is formed by isobutyrophenone
synthase from isobutyryl-CoA and three malonyl-CoAs.
The resulting aromatic intermediate undergoes a series of
prenylation reactions and finally an intramolecular
cyclization yields the bicyclic molecule. The enzyme
catalysing the first prenylation step has been characterised
as a soluble and divalent cation-dependent enzyme, which
POSTER ABSTRACTS
101
P31
in this combination is unusual for so-called aromatic
prenyltransferases. Using degenerate primers, a 340 bp
cDNA core fragment was cloned from H. perforatum buds
as well as H. calycinum ovarian walls and cell cultures. The
fragment was extended by 380 bp to the 3’-end using gene
specific and RACE primers. It exhibits between 80% and
60% sequence similarity at the amino acid level to aromatic
prenyltransferases from Oryza sativa, Arabidopsis thaliana
and Lithospermum erythrorhizon. At present, the full length
cDNA is being cloned and the encoded protein will be
heterologously expressed in E. coli for detailed
characterization.
P31: 28
Quantitative and qualitative analyses of natural product
enzyme families in seeds of Brassicaceae
Geißler R., Naumann K., Strack D. and Vogt T.
Final reactions in plant secondary product biosynthesis are
mostly performed by the enzymes of the transferase
families, e.g. glycosyl-, methyl-, glutathione- or
acyltransferases, which enable the formation of complex
conjugates. Brassica napus seeds contain a variety of
glycosylated- and/or acylated compounds, like flavonoids
and the characteristic sinapate esters, e.g. sinapoylcholine
(sinapine), derived from the general phenylpropanoid
pathway. We have initiated a combination of affinity
chromatography and 2D-electrophoresis techniques
together with mass spectrometry (MALDI-TOF MS,
nanoLC-ESI-MS) to selectively purify, detect, and
characterize complete subclusters of development- and
tissue specific transferases in B. napus seeds.
P31: 29
Regulation of 4CL isoforms in Sorbus aucuparia cell
cultures
Scharnhop H. and Beerhues L.
Institute for Pharmaceutical Biology / TU Braunschweig,
Sorbus aucuparia belongs to the family Rosaceae and
groups in the economically important subfamily Maloideae.
It is investigated due to the ability to produce biphenyls as
defence compounds. The biosynthesis of these secondary
metabolites is catalysed by a type III polyketide synthase,
namely biphenyl synthase (BIS). The preferred starter
molecule for this reaction is benzoyl-CoA. The
biosynthesis and activation of benzoic acid is poorly
understood and none of the involved enzymes is genetically
identified. Three possible routes from cinnamic acid have
been proposed: (i) CoA-dependent and β-oxidation-like, (ii)
non CoA-dependent and (iii) CoA-dependent but not βoxidation-like. To study which of this three pathways is
mainly involved in biphenyl biosynthesis, RT-PCR
experiments were used to elucidate the transcription levels
of three putative isoforms of 4-coumarate:CoA ligase
(4CL). Therefore, cell suspension cultures of Sorbus
aucuparia were treated with different elicitors. Total RNA
was extracted and RT-PCR was performed using genespecific primer pairs for each isoform. In comparison to
BIS, these 4CL isoforms showed only slight up-regulation
upon elicitor treatment. This suggests that the non CoAdependent route to benzoic acid is involved in biphenyl
biosynthesis. These findings are being confirmed by
analysing the key intermediate in this pathway to benzoic
acid, benzaldehyde.
P31: 30
Regulation of Camalexin Biosynthesis
Glawischnig E. and Rauhut T.
TU München, Lehrstuhl für Genetik, Germany;
[email protected]
Camalexin is the predominant Arabidopsis phytoalexin,
which is induced by a great variety of plant pathogens. It
originates from tryptophan and its biosynthesis involves
several cytochrome P450 enzymes, such as CYP79B2,
CYP71A13,
and
CYP71B15
(PAD3),
which
decarboxylates S-dihydrocamalexic acid to camalexin. The
camalexin specific, as well as tryptophan biosynthetic
genes show strong co-ordinate local transcriptional upregulation in response to elicitors. The molecular basis of
this characteristic feature is now studied in detail.
P31: 31
RNAi and overexpression in Coleus blumei Hairy Roots
for the validation of putative Rosmarinic Acid
Biosynthesis Enzymes
Huecherig S.
Philipps-Universität Marburg, Germany;
[email protected]
<>Several putative genes of rosmarinic acid (RA)
biosynthesis have been cloned and sequenced from Coleus
blumei (Lamiaceae). Hydroxyphenylpyruvate reductase
(HPPR) [1] and rosmarinic acid synthase (RAS) [2] are
under investigation with respect to their impact on RA
biosynthesis and accumulation. For this purpose, several
plasmid constructs have been made for expression in
Agrobacterium rhizogenes-induced hairy roots of Coleus
blumei: (1) RNAi of HPPR; (2) overexpression of HPPR;
(3) RNAi of RAS; (4) overexpression of RAS (all under the
control of the 35S promotor). Control cultures carry the
empty vectors. So far 20 hairy root lines (7 controls and 13
carrying the HPPR-RNAi construct) have been generated.
To verify the authenticity of the transgenic hairy root
cultures, PCR has been performed by amplifying the 35S
promoter. The cultures have been checked for bacterial
contamination by amplification of the agrobacterial virC
gene.To exclude a possible influence of different
combinations of the agrobacterial rol genes on
primary/secondary metabolism of the plant, the hairy root
lines have been tested for rolA, rolB, rolC. Except two, all
lines carried the three agrobacterial genes in their genome.
The two lines devoid of all three rol genes therefore are
adventitious roots.RA content as well as RAS activity of
the hairy roots have been measured several times.
Additionally, HPPR and TAT (tyrosine aminotransferase)
activities will be measured.
[1] Kim KH, Janiak V, Petersen M (2004) Plant Mol Biol
54:311-323
P31: 32
Roles of MEP pathway isogenes in secondary
metabolism acquired during land plant evolution
Walter M., Leuchte J., Floß D., Paetzold H. and Strack
D.
Leibniz-Institute of Plant Biochemistry, Halle (Saale),
The methylerythritol phosphate (MEP) pathway provides
precursors for the biosynthesis of various isoprenoid
endproducts involved in primary or secondary metabolism
of plastids. This precursor supply is upregulated in many
instances of a high demand on isoprenoid endproduct
P31
formation like carotenoid accumulation in ripening fruits or
apocarotenoid accumulation in roots colonized by
mycorrhizal fungi. However, housekeeping functions and
ecological interactions appear to be served by different
MEP pathway isogenes as shown for the first step of the
pathway catalyzed by 1-deoxy-D-xylulose 5-phosphate
synthase (DXS). (Walter et al., Plant J., 31, 243-254
(2002)). This DXS isogene divergence has been identified
in most angiosperms analyzed to date. A similar separation
of DXS functions has recently been shown for a
gymnosperm (Ginkgo biloba) as well and additional studies
on spruce DXS genes confirm its ancient origin. To further
trace back this phenomenon in land plant evolution we
have analyzed DXS isogene organization in the moss
Physcomitrella patens. Four highly similar PpDXS genes
could be identified in the moss genome. Analysis of their
expression patterns showed differences in their expression
strength but no differential regulation. The spikemoss
Selaginella moellendorfii representing a stage between
mosses and gymnosperm in the evolution of higher plants
will be targeted next. DXS isogene evolution may represent
the oldest known case of a gene duplicate recruitment for
plant secondary metabolism.
P31: 33
Rosmarinic acid synthase is a member of the BAHD
acyltransferase superfamily
Petersen M.
Philipps-Universität Marburg, Institut für Pharmazeutische
Biologie; [email protected]
Rosmarinic acid, an ester of caffeic and 3,4dihydroxyphenyllactic acid, is an important secondary plant
constitutent with antioxidant, antiviral and antibacterial
properties that is found in many groups of the plant
kingdom. An important biosynthetic step, the formation of
the ester between a hydroxycinnamate and a
hydroxyphenyllactate moiety, is catalysed by “rosmarinic
acid synthase” (4-coumaroyl-CoA:4-hydroxyphenyllactate
hydroxycinnamoyltransferase; RAS). The cDNA and the
genomic DNA for RAS have been cloned from Coleus
blumei (Lamiaceae) [1]. Comparison of the cDNA and the
genomic sequences showed an intron of 914 bp after 405
bp coding sequence shortly before the conserved amino
acid motif HxxxD(G). The enzyme belongs to the
superfamily of BAHD acyltransferases [2] which plays an
important role in secondary metabolism of plants and fungi.
The amino acid sequence revealed a high similarity to
hydroxycinnamoyltransferases involved in the formation of
chlorogenate and hydroxycinnamoylshikimate. The ORF
was actively expressed in E. coli. The enzyme only
catalysed the transfer of 4-coumaric and caffeic acid from
the respective CoA-thioesters to hydroxyphenyllactates but
not to quinate or shikimate, showing that RAS is similar
but not identical to the enzyme forming chlorogenic acid.
P31: 34
Secondary metabolism in filamentous fungi: Molecular
characterization of regulators of beta-lactam antibiotic
biosynthesis
Hoff B., Dreyer J. and Kück U.
Lehrstuhl für Allgemeine und Molekulare Botanik, RuhrUniversität Bochum, Germany; [email protected]
The filamentous fungi Acremonium chrysogenum and
Penicillium chrysogenum are the main producers of the
pharmaceutical
relevant
beta-lactam
antibiotics
cephalosporin C and penicillin. For functional gene
analysis, it is desirable to obtain gene substitutions by
homologous recombination, a process which occurs with a
rather low frequency in these fungi. A cellular feature that
decreases homologous recombination is the nonhomologous end-joining pathway, a mechanism that
involves the binding of the highly conserved Ku
heterodimer. To improve gene targeting efficiency in P.
chrysogenum, we successfully deleted the Pcku70 gene. No
impairment in vegetative growth, sporulation and penicillin
production could be assessed for the mutant strain but
relative frequencies of homologous recombination were
drastically increased to about 50-80 %. The applicability of
the Pcku70 knockout strain was tested by disrupting genes
coding for global regulators for example velvet (veA). VEA
is known to co-ordinate asexual and sexual development in
the fungus Aspergillus nidulans and was also found to
control secondary metabolism. Expression and HPLC
analyses have clearly indicated that the VEA homologue
acts as a regulator of beta-lactam biosynthesis in P.
chrysogenum as well as A. chrysogenum. In addition,
detailed microscopic analyses have shown that deletion of
veA caused alterations in hyphal morphology and
fragmentation. From the sum of our investigations, we can
conclude that the VEA homologue controls both antibiotic
biosynthesis and fungal morphogenesis in the two fungi.
P31: 35
Structure-function-analysis of two floral SABATH Omethyltransferases
Rohrbeck D., Feike J. and Piechulla B.
Universität Rostock, Biochemie, Germany;
[email protected]
Among the huge variety of volatile organic compounds
found in floral scents, O-methyl esters like methyl
salicylate and methyl benzoate are quite common. Enzymes
responsible for the final step of their synthesis are the type
III O-methyltransferases. Investigations of the biochemical
properties of the SAMT from Hoya carnosa and BSMT
from Nicotiana suaveolens revealed a high substate
specifity for salicylic acid (SA) and benzoic acid (BA),
respectively. Beside substrate specificity these enzymes are
also distinct due to their Km values to the substrates SA,
BA and SAM, and catalytic efficiencies. These features
were related to the active pocket, which consits of eleven
amino acids characterized by crystallisation of the Clarkia
breweri SAMT. The SAMT-type enzymes are highly
conserved, while the BAMT-types differ from the SAMTtype and are less conserved.
Site directed mutagenesis of presumably relevant amino
acids of the substrate binding pocket was performed and it
was expected to get information about the process of
substrate binding and conversion. We used the H.carnosa
SAMT for converting it into a BAMT-type enzyme and
vice versa the N. suaveolens BSMT into a SA specific
enzyme. Of the N.s.BSMT the following amino acids were
altered: Met 158 into His, Met 218 to Leu, Leu 234 to Trp,
Ser 344 to Phe, and vice versa for the H.c. SAMT. The
amino acid alteration Met/His is particularly important for
SA and BA discrimination, while the Ser/Phe transition
opens the active pocket for larger substrates such as
cinnamic acid derivatives and jasmonic acid.
POSTER ABSTRACTS
103
P31
P31: 36
Sulfotransferases from Arabidopsis thaliana and their
role in glucosinolate biosynthesis
Klein M. and Papenbrock J.
Universität Hannover, Institut für Botanik, Germany;
[email protected]
Sulfotransferases (SOTs) catalyze the transfer of a sulfate
group from the co-substrate 3’-phosphoadenosine 5’phosphosulfate (PAPS) to a hydroxyl group of different
substrates. In Arabidopsis thaliana three SOTs were
identified catalyzing the last step of glucosinolate (Gl) core
structure biosynthesis, called AtSOT16, 17 and 18. These
enzymes from Arabidopsis ecotype C24 were
overexpressed in Escherichia coli, purified and used to
determine substrate specificities to investigate the
possibility that each of the three desulfo-glucosinolate (dsGl) SOTs influences the Gl pattern of Arabidopsis. After
optimization it was possible to measure in vivo substrates
with non-radioactive PAPS by HPLC analysis of the
product. In vitro enzyme assays revealed a preference of
AtSOT16 for the indolic ds-Gl indol-3-yl-methyl,
AtSOT17 showed an increased specific activity with
increasing chain-length of ds-Gls derived from methionine
whereas AtSOT18 preferred the long-chain ds-Gls,
7-methylthioheptyl and 8-methylthiooctyl, derived from
methionine. In planta Gls exist side by side, therefore
initial results from one-substrate measurements, were
verified using a mixture of ds-Gls as substrates. To learn
more about these enzymes in vivo AtSOT proteins were
tested using Gl leaf extracts from Arabidopsis ecotype C24
as substrate. This study confirmed the in vitro
measurements. To compare SOTs from different
Arabidopsis ecotypes, additionally AtSOT18* from
ecotype Col-0 was used for in vitro measurements and
revealed a different behaviour on biochemical level
compared to AtSOT18 from ecotype C24.
P31: 37
Synthesis of retinoids and related apocarotenoids in
photosynthetic organisms
Al-Babili S.
Albert-Ludwigs Universität Freiburg, Germany;
[email protected]
Apocarotenoids, e.g. retinal, are carotenoid derived
compounds exerting essential functions. They are
synthesized through the oxidative cleavage catalyzed by
non-heme iron oxygenases, an enzyme family common in
all taxa. In vitro characterization of a carotenoid oxygenase
(SynACO) from Synechocystis sp. PCC 6803 revealed a
novel retinoid-forming activity. SynACO utilizes
apocarotinoids for retinal-formation, in contrast to the
animal homologs which cleave β-carotene. The elucidation
of the protein structure confirmed the experimentally
obtained data. While the function of retinal is still unknown
in Synechocystis, it is supposed to act as a chromophor of
the sensory rhodopsin in Nostoc PCC 7120. In vitro studies
with the three carotenoid oxygenases of Nostoc show a
diversity in substrates and cleavage sites. Nostoc contains,
like Synechocystis, an apocarotenoid cleaving enzyme,
NosACO, forming retinoids through cleavage of the C15C15´ double bond. The second enzyme, ND2, mediates the
cleavage of monocyclic carotenoid-intermediates and is
supposed to deliver the substrate for NosACO, while the
third one is responsible for the formation of volatile
compounds, e.g. 3-hydroxy-β-ionone, from mono- and
bicyclic xanthophylls. The diversity in function of the
carotenoid oxygenases in higher plants is mirrored in their
large number. For instance, the genome of Oryza sativa
encodes at least thirteen members of this family involved in
ABA-biosynthesis, formation of volatile compounds, and,
according to novel data, in the synthesis of yet unidentified
growth mediators.
P31: 38
The Arabidopsis CCoAOMT-gene family – tissue
specificity and functional redundancy
Fellenberg C., Vogt T., Milkowski C., Hause B. and
Lange P.
Plant natural product methyltransferases (MTs) are grouped
into two subfamilies, a large family of cation-independent
enzymes with multiple activities against various
nucleophiles, and a small subset of cation-dependent
enzymes, the caffeoyl CoA O-methyltransferases
(CCoAOMTs), only methylating aromatics with vicinal
dihydroxy groups exclusively at the meta-position. Defined
position and substrate specificities are known only for those
members of the CCoAOMT-family, that are involved in the
formation of lignin monomers. In Arabidopsis seven
CCoAOMT-genes are annotated in the databases, regulated
developmentally and on the tissue level. They code for
proteins with significant differences in substrate specificity
in vitro. One member of this subset of genes is nearly
exclusively expressed in young flower buds and the
corresponding protein exhibits a broad substrate specificity.
The tissue specific accumulation of transcript and protein
will be described and the potential role of this gene in
flower and seed development be discussed.
P31: 39
Translational and posttranslational regulation of
phytoene synthase in Arabidopsis
Maaß D., Welsch R. and Beyer P.
University of Freiburg, Institute for Biology II, Cell
Biology, Germany; [email protected]
Phytoene synthase (PSY) is the first specific enzyme in the
carotenoid synthesis pathway and is thought to catalyze the
limiting step. In the present work we investigated the
effects of an overexpression of AtPSY in transgenic A.
thaliana plants. In leaves of these plants unchanged
carotenoid contents were observed. This correlated with
unchanged PSY protein amounts as determined by Western
blot analysis, although AtPSY mRNA was increased up to
10 fold compared with wildtype levels. This indicates
regulatory mechanisms acting on the translational or
posttranslational level. However, this regulation is
abolished in callus tissues of the same transgenic lines.
Here, increased transcript levels led to both, increased PSY
protein amounts and carotenoid content. Furthermore, we
investigated the influence of the 5’ and 3’UTRs on
translation efficiencies in vitro using wheat germ lysate and
different AtPSY mRNAs carrying deletions in their 5’ and
3’ UTRs. These results were compared with the situation in
vivo. The rate-limiting role of PSY is corroborated by the
fact that certain C-terminal extensions show increased
enzymatic activity in vitro. Subsequently produced
transgenic lines overexpressing these modified versions
showed a remarkably strong increase of carotenoid content
in callus tissues of up to 40 fold compared to the wildtype.
P31/P32
P31: 40
P32: 2
Why does HMG-CoA lyase not interfere with the
cytoplasmic MVA biosynthesis in plants?
Hemmerlin A., Schaller H., Mutterer J., Tritsch D. and
Bach T.
CNRS, France; [email protected]
ABA-triggered changes in ion-channel activity
associated to stomatal movement
Stange A., Roelfsema R. and Hedrich R.
University of Würzburg, Julius von Sachs Institute,
Little is known on the function of 3-hydroxy-3methylglutaryl-coenzyme A (HMG-CoA) lyase (HMGL,
EC 4.1.3.4) in plants, other than it might participate in
leucine degradation and the mevalonate shunt (Nes &
Bach, 1985). Arabidopsis expresses two differential spliced
mRNAs coding for two putative 3-hydroxy-3methylglutaryl-coenzyme A (HMG-CoA) lyase (HMGL,
EC 4.1.3.4) with either a molecular mass of 51 kDa
(HMGL51) or 46 kDa (HMGL46). HMGL46 contains an
unusual N-terminal extension of 100 amino acids with no
targeting properties, which seems to be specific to plant
enzymes. In addition, the intact HMGL51 contains a
mitochondrial leader peptide. Transient expression of GFP
fusion proteins in tobacco cells shows that the enzyme can
either be directed to peroxisomes because of the presence
of a C-terminal peroxisomal retention motif and/or to
mitochondria depending to the expressed form and the
position of the additional 100 aa peptide within the protein.
When expressed in Escherichia coli, only a truncated (35
kDa) protein (HMGL35) led to an active enzyme catalyzing
the formation of acetyl-CoA and acetoacetate, which was
shown to be cytotoxic when expressed in Arabidopsis
plants without any targeting motif. In this way, the
cytoplasmic mevalonate pathway might be protected from
interference with HMCoA lyase during the transit to the
target organelles.
Plants lower transpiration by closing their stomata during
drought periods. The drought-induced accumulation of
abscisic acid (ABA) triggers activation of anion-channels
in the plasma membrane of guard cells. This leads to a
depolarization, which in turn activates potassium channels.
The signaling chain linking the increase in ABA to ionchannel activation and stomatal movement is subject of our
studies. To gain new insights into this process we applied a
microscopic analysis of stomatal movement and used
intracellular multi barreled electrodes. Guard cells of intact
tobacco SR1 plants were challenged with ABA. As a result
stomata close 3 min after introducing the stimulus. After 18
min stomata are closed. ABA-induced activation of anionchannels could be measured 2 min after application of
ABA and reached a maximal activity after 5 min. These
data show that anion-channel activation precedes stomatal
closure and that the maximal activity of anion-channels
correlates with a maximal velocity of stomatal closure.
Current findings regarding the relation between the
magnitude of the ABA-induced activation of anionchannels and ion-concentration changes during stomatal
closure will be discussed on the poster.
P32: SENSING IN PLANTS
P32: 1
Two WD40 proteins act redundantly to repress UV-Binduced phenolic sunscreen accumulation
Gruber H. and Ulm R.
Institute for biology II, University of Freiburg, Germany;
[email protected]
Organisms living on the surface of the earth are exposed to
natural UV-B radiation (>295 nm). Especially plants, being
sessile organisms, have to deal with UV radiation. For
plants, UV-B is not only a stress factor but also triggers
photomorphogenesis. Concerning this developmental
aspect, we still have only limited knowledge on
components mediating signal transduction and on how
integration with other environmental factors is enabled.
Recently several players were identified as part of the
regulatory UV-B signalling pathway. These include the E3
ubiquitin
ligase
CONSTITUTIVELY
PHOTOMORPHOGENIC
1
(COP1),
the
bZIP
transcription factor ELONGATED HYPOCOTYL 5 (HY5)
and UV RESISTANCE LOCUS 8 (UVR8), a protein with
show similarity to a human guanine nucleotide exchange
factor. In order to identify novel players in UV-B
signalling, we took a reverse genetic approach isolating TDNA insertion lines in UV-B activated genes. Two of them
are WDR1 and WDR2, proteins with β-propeller structure
and high amino acid homology between each other. Data
will be presented that provide evidences for their action as
repressors of UV-B signalling.
P32: 3
ABP1 and/or TIR1/AFB: Which auxin receptor triggers
rapid elongation growth?
Schenck D. and Lüthen H.
In 2005, the nuclear F-Box proteins TIR1 and its
homologues (AFB1, AFB2 and AFB3) have been identified
as auxin receptors controlling the expression of auxininduced genes. The downstream signalling pathways of
these proteins have been revealed as well as the mechanism
of TIR1 binding auxin. Another auxin receptor, ABP1, is
not a quarter as well characterised. The control of cell
cycle, activation of PM-bound K+-channels and H+ATPases or regulation of the direction of cell expansion
could be possible functions of ABP1.
Using a high-time-resolution growth assay we try to
elucidate the different roles of TIR1 and ABP1 in the
classical rapid elongation growth responses and in
protoplast swelling. Therefore we tested several A. thaliana
mutants with defects in the above-named proteins.
P32: 4
Activation of mitogen activated protein (MAP) kinases
by oxylipins
Götze S. and Roitsch T.
Julius-Maximilians-Universität Würzburg, Germany;
[email protected]
Infection of higher plants by necrotrophic fungi result in
lipid peroxidation of α-linolenic acid. While an enzymatic
pathway generates cyclic oxylipins of the jasmonate type,
the non-enzymatic oxidation by reactive oxygen species
generates a group of cyclic oxylipins including the so
called phytoprostanes. In contrast to the jasmonates, little is
known about the biological function of phytoprostanes.
Both jasmonates and phytoprostanes were shown to
POSTER ABSTRACTS
105
P32
stimulate the activation of overlapping defense related
responses. However, in tomato suspension culture cells
only treatment by phytoprostane A1 (PPA1) resulted in the
fast and transient posttranslational activation of MAP
kinases, an important signal transduction element, while
methyl-jasmonate (MeJa) was inactive. We could show that
also other enzymatically generated oxylipins, such as
OPDA and Hexenal, did not stimulate the activation of
MAP kinase activity. From all tested oxylipins only
prostaglandin A1, a signaling compound from vertebrates
which is structurally similar to PPA1, resulted in an
activation. These results could be extended to an
Arabidopsis cell suspension cultures. The specific
activation of MAP kinases by phytoprostanes in the model
plant species Arabidopsis, provides the possibility to assess
their biological function in relation to the enzymatically
generated jasmonates by functional approaches. The
identification of a specific signal transduction element will
be the basis to employ reverse genetics to elucidate the
biological role of the non-enzymatically generated
phytoprostanes.
P32: 5
Activation of pattern recognition receptors FLS2 and
EFR leads to calcium-associated opening of plasma
membrane anion channels
Becker D., Jeworutzki E., Roelfsema M. and Hedrich R.
University of Wuerzburg, Germany; [email protected]
In Arabidopsis, defense against bacterial pathogens
involves the pattern recognition receptors FLS2 and EFR.
Stimulation of these receptors through their ligands,
bacterial flagellin (flg22) or bacterial EF-Tu (elf18) leads to
a defense response and ultimately to increased resistance.
Little is known about the signaling pathway of these
receptors. Here, we characterize the early response in situ,
using an electrophysiological approach. Voltage recordings
of microelectrode-impaled mesophyll cells of wildtype
plants revealed rapid, dose-dependent membrane potential
depolarisations in response to either flg22 or elf18. Mutants
lacking the cognate receptor failed to respond. As predicted
for the parallel activation of two distinct receptors, in
wildtype plants stimulated with non-saturating levels of
both stimuli simultaneously, the depolarization response
was additive. Using ion selective microelectrodes,
pronounced anion currents were recorded upon application
of flg22 and elf18, indicating that the signaling cascades
initiated by each of the two receptors converged on the
same plasma membrane ion channels. Arabidopsis plants
expressing the calcium sensor apoaequorin revealed that
depolarization coincided with an increase in cytosolic
calcium level. Blocking this Ca2+ increase by lanthanum
abolished membrane potential depolarization. Thus,
activation of the pattern recognition receptors FLS2 and
EFR appears to lead to calcium associated plasma
membrane anion channel opening as an early step in
signaling.
P32: 6
Characterization of eid3 - a dominant hypersensitive
mutant in phytochrome signal transduction
Klose C. and Kretsch T.
Institut für Biologie 2, Schänzlestr.1, 79104 Freiburg,
The phytochrome family in Arabidopsis thaliana comprises
5 members (phytochrome A-E). PhyA is responsible for the
so-called very low fluence responses (VLFRs) and for the
high-irradiance responses (HIRs) in far-red light. PhyB is
mediating the photoreversible low fluence responses
(LFRs) in red light. The eid3 (empfindlicher im
dunkelroten Licht 3) mutant was identified in a screen for
specific mutants in phytochrome A signaling that could
overcome the red light-dependent decrease of the HIR
under alternating red and far-red light pulse treatments. The
eid3 mutant is extremely hypersensitive in red and far-red
light and is the only dominant among the eid mutants. The
mutation is caused by a single amino acid substitution.
EID3 shows predominantly nuclear localization. Double
mutant analyses show that EID3 acts in signaling pathways
downstream of phyA and phyB.
P32: 7
Detergent effects on plasma membrane lipid raft
proteins
Demir F.1, Fuchs I.1, Reinders J.2 and Hedrich R.1
1
J.-v.-Sachs-Inst. f. Biosciences, Molecular Plant
Physiology and Biophysics; 2J.-v.-Sachs-Inst. f.
Biosciences, Pharmaceutical Biology;
[email protected]
Many signalling processes are mediated through receptors
and channels in the plasma membrane. Recently, important
signalling components were found in specialized membrane
domains, so-called lipid rafts. These detergent-resistant
microdomains can be isolated from plasma membrane
fractions by treatment with different detergents. The wellknown standard setup for isolating lipid rafts from plant
plasma membranes is based on the incubation with Triton
X-100 at 4°C. It is known from studies on animal lipid rafts
that the use of different detergents, their concentrations and
incubation temperatures affects both the lipid- and the
protein composition of the respective microdomains. To
test if this also applies to plant membranes, we isolated
very pure plasma membrane vesicles from Arabidopsis
mesophyll cells. Western blot analysis as well as activity
assays of marker enzymes (cytochrome c reductase / oxidase and the V-type / F-type ATPase activities)
confirmed the purity of our plasma membrane preparation.
Using these PM-enriched membrane vesicles, we here
investigated the effects of zwitterionic, non-ionic and
alkylglycosidic detergents on the raft protein composition.
Thereby we found a detergent- and temperature dependence
of proteins extracted from lipid rafts.
P32: 8
Do GABA-shunt intermediates act as signaling
molecules in Arabidopsis thaliana?
Hüser A., Flügge U. and Ludewig F.
Universität zu Köln, Germany; [email protected]
Gamma-amino butyric acid (GABA), the main inhibitory
neurotransmitter in mammalia, occurs in all species and is
acting as a signaling molecule in organisms from
mammalia to bacteria. In plants, GABA accumulates under
various stress conditions. However, the manner of GABA
perception is unknown. Besides GABA, several substances
with a discussed signaling function - gamma-hydroxy
butyric acid (GHB) and succinic semialdehyde (SSA) occur during GABA degradation. Therefore, knock out
plants in the GABA-shunt were analyzed. Mutants of both
catabolic genes (GABA-transaminase and succinic
semialdehyde dehydrogenase (ssadh)) display phenotypic
P32
deviations to wild type; gaba-t knock out plants show a
normal vegetative growth with reduced fertility, whereas
ssadh knock out plants are severely affected in growth.
These plants can be rescued by interrupting the GABAshunt upstream of the ssadh, thereby preventing
accumulation of a potential signaling substance. To test
whether the GABA-shunt metabolites may be signaling
molecules in planta, wild type and mutant plants were
grown on media supplemented with GABA, SSA or GHB,
respectively. Each of the three substances has a specific
influence on plant growth. External GABA had dose
dependent effects, small amounts increase plant growth,
higher concentrations decrease plant size. The ssadh
phenotype could be mimicked by addition of SSA to the
growth media, whereas feeding of GHB results in altered
root architecture. These findings suggest a signaling
function for GABA-shunt intermediates in plants.
P32: 9
Effects of tocopherol and tocopherol-derivates on signal
transduction pathways and cell cycle progression in
tobacco BY-2 cell cultures
Findling S.1, Roitsch T.1 and Desel C.2
1
Department of Pharmaceutical Biology,University of
Würzburg; 2Institute of Phytology, University of Kiel;
[email protected]
Tocopherols (vitamin E) are isoprenoid lipids with strong
antioxidative activity that protect lipids such as
polyunsaturated fatty acids from oxidative damage.
Whereas various functions have been described in
vertebrates, only little is known about tocopherols and its
physiological function in plants. Some studies indicate a
role in carbohydrate partitioning, seed longevity and
germination.
Based on the finding that high levels of nitro-tocopherol
were found in germinating seeds, the question arises,
whether nitro-tocopherol is either just a by-product, or
whether nitro-tocopherol has a specific function in seedling
physiology and cellular signal transduction mechanisms.
To study the role of tocopherol and its derivates on cell
cycle progression, synchronized tobacco BY-2 cell
suspension cultures were used. Whereas α-, β-, γ-, and δtocopherol delayed cell cycle progression, tocopherolphosphate accelerated cell cyle progression.
Since it has been shown that calcium plays a role as second
messenger in the regulation of cell cycle progression, the
effect of tocopherols on calcium signaling has been
addressed. Synchronized BY-2 cells expressing the calcium
sensor aequorin are used to study the role of tocopherols on
changes in cytosolic calcium by measuring calcium
dependent bioluminescence. Application of α-, β-, γ-, and
δ- tocopherol did not elicit any significant calcium
signature. The effect of tocopherols on calcium signatures
elicited by various stress related stimuli will be reported.
P32: 10
Functional expression and characterization of a lightactivated adenylyl cyclase from E. gracilis
Looser J.1, Schroeder-Lang S.2 and Nagel G.1
1
Universität Würzburg, Julius-von-Sachs Institut, 97082
Würzburg, Germany; 2Max-Planck-Institut für Biophysik,
60439 Frankfurt, Germany; [email protected]
is enhanced by blue light. Each subunit harbors two BLUFtype photoreceptor domains, binding flavin adenine
dinucleotide, and two catalytic domains that are
homologous to class III adenylyl cyclases. Expression of a
light-sensitive adenylyl cyclase in cells would allow the
manipulation of cAMP with exquisite spatiotemporal
control. To this end, we functionally expressed PACs
(encoded by PACα and PACβ) in Xenopus laevis oocytes.
We used the human cystic fibrosis transmembrane
conductance regulator (CFTR) as a cAMP sensor to
monitor light-induced changes in [cAMP]i. CFTR is a
chloride channel that is activated by phosphorylation via
cAMP-dependent protein kinase (PKA). A short pulse of
blue light caused a strong increase in conductance after a
delay of 15-20s. For strong irradiation, the delay of the
electrical response was as short as 2s.
To examine the kinetics of the light-induced cAMP
production, we coexpressed PACα or PACβ with cyclic
nucleotide-gated (CNG) channels which are directly
opened by cAMP. In these oocytes the photocurrent
increased almost instantaneously after the onset of
irradiation. The time constant of the activation of PACα
was determined to be ≤ 20ms. Light-dependent activity of
PACα switches off within ≤ 10ms after light has been
switched off.
P32: 11
G-protein subunit α and phospholipase A2 form a signal
transducing complex in the plasma membrane of
Heinze M., Schwartze W. and Roos W.
Martin-Luther-University of Halle, Germany;
[email protected]
Plant heterotrimeric G-proteins are involved in a variety of
signal paths though only one α and few βγ isoforms exist.
In isolated plasma membranes the Gα subunit was
solubilized and immunodetected by different antisera.
Immunoprecipitates obtained with antisera against random
sites of recombinant Gα contain a complex of Gα and
phospholipase A2 (PLA2), antisera against the effector
coupling site of Gα precipitate Gα, but no PLA2. In the
immunocomplex and in the solubilized plasma membrane,
the activity of PLA2 is stimulated upon activation of Gα by
GTP. This stimulation is lacking in plasma membranes or
immunoprecipitates obtained from cells expressing much
less Gα due to antisense transformation, indicating PLA2 as
a target of contol by Gα. In intact cells, both antisense Gα
transformation and the expression of antiGα-scFv
antibodies cause a reduction in the elicitor-activation of
PLA2 and in the following phytoalexin response. The close
interaction of Gα and PLA2 indicated by these findings is
pH sensitive: the stimulation by GTP disappears at pH 9.5
compared to the usual pH 7.5. Non-denaturing PAGE
shows that PLA2 is present together with Gα in complexes
>100 kDa; after shifting the pH to 9.5, PLA2 is liberated
from these complexes. The occurrence of similar-type
complexes of multiple target proteins sharing the same Gsubunit(s) could be one way to generate the variety of Gαmediated signaling and complement the modulating
function of G-proteins in hormonal signal transduction.
The flagellate Euglena gracilis contains a photoactivated
adenylyl cyclase (PAC), which is crucial for
photoavoidance. It is composed of two PACα and two
PACβ subunits, which exhibit adenylyl cyclase activity that
POSTER ABSTRACTS
107
P32
P32: 12
P32: 15
In guard cells of Nicotiana tabacum, abscisic acid
increases anion channel activity with and without
changes in cytoplasmic free Calcium concentration
Marten H., Konrad K., Roelfsema M. and Hedrich R.
Universität Würzburg, Germany;
[email protected]
Monitoring signal induced changes in membrane
potential on the basis of the voltages sensitive dyes ABA triggered membrane depolarization in guard cells
Konrad K. and Hedrich R.
University Würzburg, Institute for Molecular Plant
Physiology and Biophysic; [email protected]
Drought induces stomatal closure, a response that is
associated with the activation of plasma membrane anion
channels in guard cells, by the phytohormone abscisic acid
(ABA). In several species, this response is associated with
changes in the cytoplasmic free Ca2+ concentration. In
Vicia faba, however, guard cell anion channels activate in a
Ca2+-independent manner. Because of potential differences
between species, Nicotiana tabacum guard cells were
studied in intact plants, with simultaneous recordings of the
plasma membrane conductance and the cytoplasmic free
Ca2+ concentration. ABA triggered transient rises in
cytoplasmic Ca2+ in the majority of the guard cells (14 out
of 19). In seven out of 14 guard cells, the change in
cytoplasmic free Ca2+ closely matched the activation of
anion channels, while the Ca2+ rise was delayed in seven
other cells. In the remaining five cells, ABA stimulated
anion channels without a change in the cytoplasmic Ca2+
level. Even though ABA could activate anion channels in
N. tabacum guard cells independent of a rise in the
cytoplasmic Ca2+ concentration, patch clamp experiments
showed that anion channels in these cells are stimulated by
elevated Ca2+ in an ATP-dependent manner. Guard cells
thus seem to have evolved both Ca2+-independent and dependent ABA signaling pathways. Guard cells of N.
tabacum apparently utilize both pathways, while ABA
signaling in V. faba seems to be restricted to the Ca2+ independent pathway.
Plant Physiology, January 2007, Vol. 143, pp. 28–37
P32: 13
Interactions of uranium with Brassica
Viehweger K. and Geipel G.
Forschungszentrum Dresden-Rossendorf, Germany;
[email protected]
Uranium is a widespread radioactive toxic heavy metal,
released into the biosphere mostly by military purposes and
nuclear industry. It is taken up by plant root systems and its
chemical toxicity is much more dangerous than the
radiological. Thus cell suspensions of rape (Brassica
napus) revealed similar defence mechanisms after uranium
exposure as described for other heavy metals (Clemens
2001). Some of them will be presented in detail, e.g. the
pH-shift of the outer medium, the uptake and cellular
sequestration revealed by ICP-MS and confocal
microscopy. The speciation of uranium in aqueous
solutions depends strongly on the pH-value, ionic
composition and strength and thus plays an important role
in bioavailability and cytotoxicity respectively. To
investigate the speciation of uranium time-resolved laserinduced fluorescence spectroscopy (TRLFS) was
performed. Further investigations are under way to clarify
the molecular interactions between possible cellular ligends
and uranium.
Celemns, S. (2001). "Molecular mechanisms of plant metal
telerance and homeostasis." Planta V212 (4): 475-486.
The phytohormon abscisic acid (ABA) has been shown to
activate anion channels, that cause a plasma membrane
depolarisation and in turn a voltage activation of K+ release
channels. Membrane potentials of single guard cells can be
precisely measured with voltage-recording microelectrodes.
This technique is time consuming and only allows
measuring one cell at a time, additionally damages vitality
of cells. There for it is not well suited for rapid screens of
large sample numbers. To provide the basis for high
throughput membrane potential recordings, we tested the
suitability of two voltage sensitive dyes, DiBAC4(3) and
the FMP dye, for this purpose. Using the membrane
potential dye DiBAC4(3) batches of up to hundred intact
Vicia faba guard cell protoplasts could be measured
simultaneously, in a non-invasive manner. ABA treatment
caused a reversible rise in DiBAC4(3) fluorescence which
symbolised
a
phytohormon
induced
membrane
depolarisation. It was possible to quantify this potential
change according to the Botzmann fit of the DiBAC4(3)
calibration with the patch-clamp technique. Changes in
vacuolar membrane voltage could be resolved as well in
Arabidopsis thaliana mesophyll vacuoles. After ATPapplication
to
a
current-clamped
vacuole,
a
hyperpolarisation could be monitored due to the activity of
the H+-ATPase, which was accompanied with a
simultaneous fluorescence rise. This method opens up the
possibilities to monitor electrogenic events at the plasmaand vacuolar membrane in intact systems thus investigating
signalling cascades in terms of ion fluxes.
P32: 16
Protein-, mRNA-, and protein phosphorylation patterns
of Eschscholzia cells during elictor-triggered signaling
Buchheim M., Angelova S. and Roos W.
[email protected]
The expression of secondary metabolism by contact with
fungal elicitors reflects the activation of at least two signal
chains in cultured cells of Eschscholzia californica. We
have shown earlier that low concentrations of a yeast
glycoprotein elicitor signal via the stimulation of
phospholipase A2 and intracellular pH shifts, whereas high
elicitor concentrations involve a peak of jasmonate and
hypersensitive cell death (review: Roos et al. J. Plant
Physiol. 2006, 163:369-381). Downstream of the pH shift,
changes of biosynthesis and stability have been
demonstrated for a number of proteins by combined 2D
analysis of soluble proteins and those produced from the
actual mRNA population by in-vitro translation. For this
purpose, artificial pH shifts have been evoked by different
methods, that induced genes overlapping with those
activated by elicitor contact. Immediately after the pH shift,
changes in the phopshorylation state of about 5 proteins
have been observed, that are, however, not overexpressed.
Sequencing of these signal proteins is under way.
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P32: 17
P32: 20
Searching for interactors of the plant heterotrimetric
G-protein
Wolf C. and Roos W.
[email protected]
Spectral properties of Agrobacterium tumefaciens Agp2
are modified by specific compounds of the cell extract
Molina I.1,2, Krieger A.1, Oberpichler I.2 and Lamparter
T.2
1
FU Berlin, Germany; 2TU Karlsruhe, Germany;
[email protected]
The multitude of signaling functions of plant heterotrimeric
G-proteins contrasts with the existence of only one or few
of their subunits. We put the question whether the same Gα
subunit forms complexes with a variety of target proteins
and thus controls a multitude of second messengers. The
following methods are in use to screen for potential Gαtargets among Arabidopsis proteins:
a) binding studies at immobilized recombinant, His-tagged
Gα
b) co-immunprecipitation of solubilised plasma membrane
proteins with anti-Gα antibodies of different epitope
specificity
c) the split-ubiquitin-system with Gα as bait
The latter method detects interactions between test proteins
coupled to N- or C-terminal parts of ubiquitin that occur
during the mating process of two yeast cell lines (Obrdlik et
al., 2004). First putative interactors of Gα are identified,
among them phospholipase A2 (analogous to data from
Eschscholzia californica, cf. Poster 658), a SNARE-like
protein and the DREPP plasma membrane protein (hitherto
of unknown function).
The split-ubiquitin approach, which is more laborious to
establish, reports binding partners with higher fidelity. The
candidate proteins obtained with this method are under
sequencing.
P32: 19
Spatial and kinetic properties of the stomatal humidity
response
Legner N. and Kaiser H.
Botanical Institute, CAU Kiel, Germany;
[email protected]
Stomata sense atmospheric humidity via the transpiration
rate, thus forming a feedback loop which controls leaf
water loss. The sensor for transpiration sensing and its
localization is still not identified.
There are two general possibilities: either transpiration
could directly be sensed in or in the direct vicinity of the
guard cells or surrounding leaf tissues could transmit a
transpiration dependent signal to the guard cells. The latter
should result in a large effect of the transpiration of
surrounding pores and a delayed kinetics compared to
stimuli which are sensed intracellularly. To test these
predictions, the stomatal response of Sambucus nigra to a
transition to dry air was observed after blocking
transpiration of single stomata by applying droplets of oil
to the pore. This treatment did not reduce stomatal closure.
Additional occlusion of the adjacent pores as well as
restricting transpiration to an area of 0.8 mm2 clearly
reduced the closing response. Consequently strictly local
processes triggered by a pore's own transpiration are neither
required nor sufficient to induce full stomatal closure.
Additionally we compared the response to light/darkness
transitions, which are sensed intracellularly, with that to dry
air. Whereas stomata nearly immediately responded to
light/dark transitions, the transpiration induced closure as
well as the opening response after transition to humid air
were clearly delayed. These results are consistent with the
generation of a signal in the surrounding tissue which
requires some time to travel to the guard cells.
Phytochromes are photochromic photoreceptors with a bilin
chromophore.
The
tumour-inducing
bacterium
Agrobacterium tumefaciens contains two genes that encode
for phytochrome-homologous proteins, which are termed
Agp1 and Agp2. Opposed to most other phytochromes,
Agp2 converts from the so-called Pr form to the so-called
Pfr form in darkness. Here, we analysed the
photoconversion and dark-conversion of full-length Agp2
and the truncated protein Agp2-M2, which consists of the
N-terminal 501 amino acids (chromophore module) of the
protein, under different conditions.
It has been noted before that the spectral properties of Agp2
are modified by compounds of the Agrobacterium cell
extract. This effect was analysed in more detail. In Agp2
concentration series, the modification was only found for
rather low concentrations. The effect is thus based on an
interaction with a limiting, specific factor of the cell
extract. Spectral properties of the truncated Agp2-M2 are
modified by the extract in a more complex way.
Competition experiments in which low-concentrated Agp2
holoprotein, excess Agp2-M2 apoprotein and cell extract
were mixed, imply that the interaction of the cellular factor
is with the N-terminal part of the protein.
P32: 21
The micro-compartmentation of cytosolic
glyceraldehyde 3-phosphate dehydrogenase (GAPDH)
in plant cells
Wojtera J., Holtgrefe S., Linke V. and Renate S.
University of Osnabrück, Plant Physiology Dep., Germany;
[email protected]
In the last years it became evident for the animal system
that glycolysis is compartmentalized in the cytosolic
environment not only in a soluble form, but also associated
with the cytoskeleton and/or membranes. It is not
completely clear, whether these enzymes function as
metabolon enabling metabolite channelling or form a
reservoir of inactive enzymes. In plants, it has been
doubted for a long time that such substructures are present,
but the association of aldolase and GAPDH with the
cytoskeleton has been shown recently in developing maize
endosperm [Azama et al.: Planta 217 (2003), 628–638].
The entire glycolytic pathway was found to be associated in
an active form with Arabidopsis mitochondria [Giege et al.:
Plant Cell 15 (2003), 2140–2151]. In our group the yeast
two-hybrid system has been applied to identify proteinprotein-interaction partners of actin from hypoxic maize
seedlings. Among other proteins three cytosolic isoforms of
GAPDH were found [Holtgräwe et al.: Physiol Plant 125
(2005), 141–156]. By means of epifluorescence and
confocal laser scanning microscopy we present the
localization of cytosolic GAPDH fused to GFP in
transiently transformed protoplasts from A. thaliana. Apart
from its cytosolic distribution, the localization in form of
locally associated complexes and also the nuclear
compartmentation of GAPDH is demonstrated, what
corresponds to the animal model. Since the physiological
context in planta remains to be revealed, we currently
POSTER ABSTRACTS
109
P33
investigate the effects of chemical modifications of the
enzyme upon its intracellular localization.
P33: SEXUAL PLANT
REPRODUCTION
P33: 1
Achene heteromorphism in Chrysanthemum
coronarium L.
Brändel M. and Jensen K.
University of Hamburg, Biocentre Klein Flottbek,
Seed heteromorphism can widen the ecological amplitude
of a species as the different seeds differ in dispersal,
germination and/or seedlings growth. Therefore such
species are better adapted to environmental fluctuations.
Chrysanthemum coronarium is an annual plant which
produces three types of achenes within one capitulum. The
aim of the study was to determine if differences in achene
morphology have effects on germination, seedlings growth
and on achene production of plants growing out of the
different morphs.
Plants growing out of the three morphs did not differ in the
number of produced morphs per capitulum. Moreover, the
mass of the three morphs showed no significant differences
between those plants. But germination percentages showed
significant differences between seed from central and
peripheral plants.
Seeds of the three morphs germinated over the same range
of temperatures (3-30°C), but germination percentages
were significantly different between the three morphs.
Peripheral seeds showed the lowest and central seeds the
highest germination.
Seedlings of the three morphs showed no significant
differences in weight.
In C. coronarium peripheral seeds had a higher degree of
dormancy and a thicker pericarp which may serve as
protection against soil biota and mechanical damage. In
contrast, the central seeds germinated to high percentages
(>50%) over a wide temperature range (3-24°C). To
produce seeds on one individual plant which show such
differences in germination characteristics represent a good
strategy for population persistence especially for an annual
plant.
P33: 2
ISOLATION OF REPRODUCTIVE CELLS OF
BRACHYPODIUM DISTACHYON; A MODEL
GRASS FOR FUNCTIONAL GENOMICS
Thuruthiyil D., Graff A. and Kranz E.
Hamburg University, Germany;
[email protected]
ISOLATION OF REPRODUCTIVE CELLS OF
BRACHYPODIUM DISTACHYON; A MODEL GRASS
FOR FUNCTIONAL GENOMICS T. Dennis Thomas*,
Alexandra Graff and Erhard Kranz Biozentrum Klein
Flottbek, Ohnhorststraße 18, 20609, Hamburg The
importance of a model plant system has been well
illustrated in modern biology by Arabidopsis thaliana, a
dicot plant. Recently Brachypodium distachyon has been
proposed as a new model system for monocot due to its
unique properties of a model system such as small size,
short generation time, self fertile, small genome size etc.
The isolation of embryo sac cells and sperm cells lead to
detailed studies at single cell level. In the present study the
egg and sperm cells were isolated from B. distachyon var
ABR1. The flowering spikes were emasculated five days
before anthesis, unfertilized ovaries were isolated in aseptic
condition and treated with a 0.5mL cell wall degrading
enzyme mixture for 10 minutes followed by keeping the
ovaries in 600 mosM/kg H2O mannitol solution. The
ovules were isolated by dissecting the ovaries with sharp
glass needles. The embryo sac cells were isolated by
dissecting the nucellus using glass needles under
microscopic observation. Egg and central cells were
isolated. For sperm cell isolation, about 1000 pollen grains
were added in to mannitol solution. Sperm cells were
released from the pollen grains after it ruptures by osmotic
shock and selected by using a micropump. *Permanent
address: Department of Botany, St. Thomas College, Pala,
Arunapuram (P.O), Kottayam (D.T), PIN-686574, Kerala,
India
P33: 3
Phytohormones in the progamic phase of fertilization in
self-compatible and self-incompatible clones of petunia
(Petunia hybrida)
Kovaleva L., Timofeeva G., Zakharova E., Minkina Y.
and Rakitin V.
Institute of Plant Physiology , Russian academy of
sciences, Russian Federation; [email protected]
The contents of IAA, ABA, and cytokinins, as well as the
content of ACC, the rate of ethylene production, and the
activity of ACC-synthase and ACC-oxidase in the pistils
and their parts (stigma, style, and ovary) were measured
over an 8-h period following compatible SC) and selfincompatible (SI) pollination. The dynamics of ethylene
production by petunia pollen-pistil system indicated that
the stigma is the main site of ethylene synthesis. Pollen
grain germination after SC pollination was characterized by
high ACC content, after SI pollination by the lowest ACC
level. The greatest ethylene evolution was recorded in the
case of self-pollination of SI clone. The hormonal status of
the petunia pollen-pistil system under SI pollination
differed dramatically from that under SC pollination. In the
case of SI pollination, pollen germination was accompanied
by ethylene evolution exceeding that in SC pollination and
by a 3-fold increase in ABA content, whereas growth
inhibition of pollen tubes through the conducting tissue of
style was accompanied by a 5-fold increase in cytokinin
content and high levels of ABA in the pollen-pistil
system. Taken together, the hormonal status of petunia
pollen-pistil system indicates that ethylene signal pathway
is integrated through a network of cross-talking
connections with ABA and cytokinins that appear to
coordinate responses in the pollen-pistil interactions after
SI pollination.
The work is supported by RFBR, grant no.06-04-48870.
P33: 4
Seed and pollen dispersal strategies and their effect in
the population structure of a subtropical conifer species,
Brazilian pine
Stefenon V., Gailing O. and Finkeldey R.
University of Goettingen, Germany;
[email protected]
Due to morphological features of pollen and seeds, limited
gene dispersal has been proposed for A. angustifolia. Pollen
grains of this species are large and have less ability to float.
P33/P35
Seeds are heavy (about 8.0 g), dispersed mainly through
gravity and occasionally by animals. However, seeds
dispersed by animals are usually damaged and not able to
germinate. Although the physical features of the pollen
grains suggest narrow dispersion, ecological features of the
species likely aid the pollination of the female strobili. A.
angustifolia occupies the upper canopy of the forest and the
strobili are located at the end of the branches. These
characteristics likely compensate at least partially the poor
flight ability of pollen. Regarding secondary seed dispersal
by animals, more studies are needed to highlight the
behaviour of potential seed dispersers and its importance
for the gene flow.
Our indirect estimations of both spatial genetic structure
and migration rate suggest relatively short-distance gene
dispersal. However, more efficient dispersal within
populations was observed in at least one out of six stands.
Although some proportion of seed dispersal may be
aggregated, reasonable secondary seed dispersal and the
overlap of seed shadows is suggested. Given the
environmental heterogeneity in the distribution range of A.
angustifolia, high adaptability is critical for the endurance
of natural populations. Therefore, strategies for
maintenance of gene flow among remnants must be
considered with the aim of diminishing the negative
consequences of population fragmentation.
P33: 5
Two SPO11 genes of Arabidopsis thaliana are essential
for the initiation of meiosis
Hartung F., Suer S., Wurz R. and Puchta H.
University of Karlsruhe, Germany;
[email protected]
SPO11, a homologue of the subunit A of the
archaebacterial topoisomerase VI, is essential for doublestrand break induced initiation of meiotic recombination. In
contrast to single homologues in animals and yeasts we
found three homologues in Arabidopsis thaliana and other
plants. Whereas AtSPO11-3 is involved in somatic
endoreduplication, Atspo11-1 mutants have a meiotic
phenotype similar to spo11 mutants of non-plant
organisms. Analysing a T-DNA insertion mutant, we were
now able to show that AtSPO11-2 is also required for
meiotic recombination and chromosome segregation, a
phenotype that can be reversed by complementation.
Atspo11-2 mutant plants are almost sterile, severely
impaired in meiotic divisions, and show random
segregation of chromosomes leading to aneuploidy in the
progenies. The phenotype of the mutant is similar to the
spo11-1 single mutant and the double mutant spo11-1/-2
does not differ phenotypically from the single mutants.
Thus, surprisingly, two SPO11 homologues are required for
initiation of meiosis in plants.
P35: TROPICAL ECONOMIC
PLANTS
P35: 1
Work related to the Quality of Cocoa (Theobroma
cacao)-The Influence of Post-harvest Processes
Rohsius C., Stoll L., Kadow D., Niemanak N. and
Lieberei R.
University Hamburg, Germany; [email protected]
Apart from genotype specific differences and
edaphoclimatic conditions, mainly post harvest-processes
influence the aroma-related quality of raw cocoa. In order
to display and describe possible quality differences
between cocoa shipments from different producing areas,
samples from 22 countries were analysed. Further studies
investigated the influence of single fermentation
parameters, such as acidification and temperature, on the
formation of specific aroma precursors, off-flavour
reduction and quality effecting enzymes. The following
aspects will be displayed: Cocoa Atlas:Quality parameters
for 122 raw cocoa samples traded in Germany were
analysed during this project. Fine and bulk Cocoa:Data
from the Cocoa Atlas allowed us to identify fine and bulk
cocoa from producing countries. Caffeine and theobromine
are the most important parameters for making these
distinctions. Model Fermentation Methods:Fermentationlike incubations under controlled conditions enabled us to
analyse the influence of different factors such as the
temperature regime and the effects of acidification and the
oxygen supply on aroma precursors. Enzymes:The change
of activity of the polyphenol oxidase, aspartyl endoprotease
and carboxypeptidase were measured under different
fermentation
conditions.
Fermentation
versus
Germination:The proteolytic decomposition of storage
proteins during fermentation was compared to the
germination process. GABA:Formation of the bitter tasting,
non proteinogenic amino acid GABA, during fermentation
and germination was shown in both the fermentation and
germination processes.
P35: 2
A survey of variety and diversity of Boraginaceae in
Kerman province (a tropical region),and a comparative
study of these plants with those in Iran
Mirzabagheri D.1, Soltani A.2 and Sharifnia F.3
1
Islamic Azad university,Bam Branch,Bam,Iran, Iran;
2
Khatemolanbeia high school , Azadi square,Kerman,Iran;
3
Islamic Azad university,North Tehran Branch,Tehran,Iran;
[email protected]
Boraginaceae family is one of the large families of plants is
the world whose geographic range is in tropical and
subtropical areas . Most of its species ,however,are
concentrated in the Mediterranean areas . This family
consist of 117 genera and about 2400 species . from among
the species discovered in Iran , 54 species are endemic to
Iran , out of which 15 species exist in a limited small region
in Iran . From among all species in Iran , 26 species merely
exist in one region , 17 species are found in two region ,
and 12 species are exclusively found in the Caspian sea
region , 42 species are merely found in the northern region ,
and six species are found merely in the southern part of the
country on the shores of the sea of Oman and near the
Persian Gulf .From among the existing species , 44 species
POSTER ABSTRACTS
111
P35
belong to 15 genera in Kerman province , out of which
Heliotropium (12 species),Lappula (5 species),Paracaryum
and Rochelia (4 species each),have the most number of
species ,respectively . No species endemic to Kerman
province was found , and 3 species which had already been
reported from other parts of the country were introduced
from this province for the first time , too . The full check
list for all information mentioned , together whith the
method of their diversity , is avalaibale . A key has also
been prepared for the local identification of species and
genera of this family in the related region .
P35: 3
Development of Phalaenopsis plants depending on
culture parameters in a temporary immersion system
(TIS)
Wollschläger J., Saare-Surminski K. and Lieberei R.
Universität Hamburg, Biozentrum Klein Flottbek,
The development of plant in vitro propagation systems to
produce identical genotypes of given plants under
laboratory conditions was traditionally based on solid
culture media systems. New approaches are based on liquid
media which is provided in rhythmic patterns. These new
systems are called temporary immersion systems (TIS) and
have been set up for several plants with high importance in
horticulture and medicine. Due to the fact that TIS provide
different culture conditions for the plants by comparison
with the culture on solid or in liquid medium where the
plants are permanent immersed, it is still possible to
optimize the steps needed for mass production.
It has been shown that TIS provide a lot of advantages
compared with conventional in vitro-techniques: Biomass
accumulation and shoot multiplication are increased, and
there are less plants which show hyperhydricity, an often
occurring, but not completely understood phenomenon in
tissue culture of plants.
In this study was analysed, how far different culture
conditions influence the growth and multiplication of
Phalaenopsis shoots in a TIS. The varied culture
parameters were light intensity, sugar content of the
nutrient medium and frequency of immersion with nutrient
medium.
In the second part of this work the surface of Phalaenopsis
shoot leafs grown under different culture conditions are
examined with a light- and a scanning electron microscope
(SEM). It can be shown that there is a marked difference
between the leaf surfaces of in vitro and ex vitro shoots.
P35: 4
Histological and physiological modifications during
peach palm germination
Steinmacher D.1,2, Saare-Surminski K.1 and Lieberei R.1
1
Universität Hamburg, Germany; 2Fellow of
CNPq/Brasilia, Brazil;
[email protected]
Peach palm (Bactris gasipaes Kutnh), a palm tree native
from the Amazon basin, is today important for its fruit and
heart-of-palm. Considering its increasing importance, it is
worthy
understanding
the
modifications
during
germination. In the present study, histological and
physiological modifications occurring in the endosperm as
well as the free amino acids pool of the haustoria during
germination was studied. Peach palm germination started
approximately 2 months after sowing. Histological
analyses revealed that the peach palm endosperm is
composed of living cells, with thick cell walls and several
protein and lipid bodies. The growth of the haustorium was
correlated to the growth of the seedling and also to
histological modifications of the endosperm cells,
especially in the cells adjacent to the growing haustorium.
First modifications occurred on proteins bodies, where
changes from proteins bodies to one vacuole with granular
aspect were seen. This was concomitant with thinner cell
walls and later with the degradation of the cytoplasm
content and the collapse of cell walls. Free amino acids
pool revealed that the major free amino acid in zygotic
embryos was glutamine, which showed a continuously
increase during haustorium development. Most of the other
amino acids showed a reduction of the initial amount and
remained stable during the period evaluated. This work
suggests that during peach palm germination the storage
proteins are the first reserve compounds mobilized and
used by the growing seed.
P35: 5
Optimization of Nucleic Acid Isolation Protocols for
Tropical Medicinal Plants
Panes V., Altarejos A., Go C., Berina R., Carballo C.
and Tolentino V.
Ateneo De Manila University, Philippines;
[email protected]
The hundreds of tropical medicinal plants in the Philippine
flora are attracting more attention among plant
researchers because these plants produce a high array of
secondary metabolites which impart upon these plants
medicinal properties.
However, these secondary
metabolites bind to the plants' nucleic acids and hinder the
isolation of these nucleic acids. This study focused on the
optimization of nucleic acid isolation protocols suitable for
tropical medicinal plants. Eight medicinal plants were
used such as: Allium sativum L., Artemisia vulgaris L.,
Blumea balsamifera L., Coleus amboinicus Lour., Curcuma
longa L., Mentha cordifolia L., Vitex negundo L. and
Zingiber officinale L. Three genomic DNA isolation
protocols (two from Pirttila et al. 2001 and one from
Khanuja et al. 1999) and two protocols for total RNA
isolation (modified from Bekesiova et al. 1999; Gilmartin
and Bowler 2002) were optimized. The first protocol by
Pirttila et al. 2001 emerged as the best DNA isolation
protocol for five plants, such as A. sativum, A. vulgaris, C.
amboinicus and Z. officinale. DNA yield is very high at
82.91 mg/mL. On the other hand, the best total RNA
isolation protocol for four plants, namely Artemisia
vulgaris, Mentha cordifolia, Curcuma longa and Zingiber
officinale is the Bekesiova et al. 1999 modified protocol
which uses the CTAB method of RNA isolation. It also
produced high yield of total RNA (22.96 mg/mL).
P35: 6
Posttranslational regulation of beta-glucosidase activity
in leave tissue of Hevea brasiliensis
Kadow D., Lieberei R. and Voß K.
Universität Hamburg, Germany;
[email protected]
The rubber tree Hevea brasiliensis is a cyanogenic plant,
which liberates HCN after tissue injury. In plant
environment most injuries are either caused by herbivore
attack or by microbial infection. The production of HCN is
a two step process: 1. The cyanogenic precursors for HCN
formation which are stored in the vacuoles as beta-
P35/P36
3
glucosides are liberated in the course of cell destruction. 2.
The precursors are cleaved by an apoplastically localized
beta-glucosidase (linamarase). The resulting aglycon
(alpha-hydroxynitril) decays to form HCN and a carbonyl
compound.In plant herbivore interaction the liberation of
HCN follows clear kinetics and depends on the amount of
the cyanogenic precursors and the activity of the betaglucosidase (linamarase). HCN acts as a very efficient
feeding deterrent e.g. in lima bean (Ballhorn et. al 2005)
but it impairs the plants´ defence against microbes
(Lieberei et al. 1989). The linamarase of H. brasiliensis has
been isolated and widely sequenced. Its molecular special
character is the formation of homooligomeres which form a
ladder of active enzyme in native zymograms.Recently we
have shown that the activity of beta-glucosidase in rubber
tree is sensitive to tissue injury. Upon leaf cell disruption it
raises up to 40 fold. The activation process occurs within
seconds and is a so far not described post translational
modification of beta-glucosidase activity with impact on
kinetics of HCN liberation and consequently on plant
resistance mechanisms.
P35: 7
The most important ecological factors affecting the
diversity and change in the plant cover in southwest of
Kerman province (a tropical region in Iran)
Mirzabagheri D.1 and Sharifnia F.2
1
Islamic Azad university , Bam Branch , Bam , Iran;
2
Islamic Azad university,North Tehran Branch,Tehran,Iran;
[email protected]
The region under study with an area about 40000 hectares
is located in the southwest of one of the southern provinces
of Iran . During 2 years of growth (2003_2005),200
species belonging to 47 orders and 145 genera have been
identified . A list of all identified plants in the region as
well as medicinal plants and those introduced from this
province for the first time is avalaible . Then a study was
carried out with regard to the most important ecological
factors effective in the diversity and change in the plant
cover in the region . For this reason , six factors were taken
into consideration : 1.light , 2.Relief; for this purpose , the
region was divided into three major topographic classes
(Plain,semi-mountainous,mountainous )And then the plant
cover in each part was studied and evaluated . 3.Climate
(with regard to meterological studies , the region was
divided into two climatic parts , and the plant cover was
studied and evaluated in each , separately) . 4.Soil
5.Percentage and direction of slope 6.Biological factors ,
(For this purpose , the cross effects of plants on one another
, the cross affects of plants and animal on one another , and
the role of man and domestic animals on diversity and
change in plant cover were studied . also , with regard to
the role of man and domestic animals , the region under
study was devided into two separate parts so that one part
was introduced as protected , and man and cattle were
prevented from entering the area for 2 years ) .
P35: 8
Efficient in vitro micropropagation of Ornithogalum
oligophyllum E. D. Clarke
Özel C.1, SUR I.1, Khawar K.2, Cam D.1, Ates M.1,
Özdemir F.1, Sahbaz R.3 and Arslan O.1
1
Department of Biology Education, Gazi University,
Ankara, Turkey, Turkey; 2Department of Field Crops,
Faculty of Agriculture, University of Ankara, 0;
Department of Ecology and Crops Science, Biocenter
Klein Flottbek, Univer; [email protected]
Ornithogalum oligophyllum E. D. Clarke, family Liliaceae,
is perennial plant that grows widely in Balkan countries,
Anatolian Turkey and Georgia at altitude of 700 to 3000 m.
It has great potential as ornamental cut flower or garden
plant because of silky textured very attractive white colored
flowers. The plant has not reached its commercial potential
and need developments as new flower bulb crop. In line
with the objectives of the study, In vitro bulblet
regeneration of O. oligophyllum; was achieved using twin
scales bulb explants on MS medium supplemented with 1-2
mg l-1 BAP - 0.5-1.0 mg l-1 IBA. The primary adventitious
bulbs regenerated from twin scales were sub cultured on
the same medium to achieve bulblet regeneration and
increase bulb diameter. The highest adventitious bulblet
regeneration was achieved on MS medium containing 2 mg
l-1 BAP - 0.5 mg l-1 IBA. Subsequently all plants were
acclimatized in the Sanyo Versatile Environmental
chamber for onward transfer to the green house for
flowering. The described procedure could be used for
commercial, rapid and out of season multiplication of this
plant.
P36: WETLAND ECOLOGY
P36: 1
Ecological aspects of pigmy Drosera (Droseraceae) in
heath ecosystem on ‘Beach Ridges Interspersed with
Swales’ (BRIS) soil in Terengganu, Malaysia
Mohd Salim, Halim J.
University Malaysia Terengganu, Malaysia (UMT),
Malaysia; [email protected]
Tropical heath ecosystem supports fewer species than other
ecosystems in the tropics, but plant species thrived here are
more likely to interact with other organisms for scarce
resources on such oligotrophic site. The occurrence of a
carnivorous plant species, Drosera (Droseraceae) on the
‘beach ridges interspersed with swales’ (BRIS) soil in
Melaleuca stands in Setiu district of Terengganu, Malaysia
is discussed in terms of taxonomy descriptions, seed
biology and conservation status. This report is important to
provide a basis for in situ conservation of neglected heath
ecosystem on BRIS soil of Terengganu, Malaysia.
P36: 2
Floristic Composition and Environmental
Characteristics of Abu-Za’abal Artificial Wetland,
Egypt
Galal T.1 and Khalafallah A.2
1
Helwan University, Egypt; 2Ain-Shams University, Egypt;
[email protected]
The aim of the present study is to provide a description of
the floristic composition and life form spectrum of the
recorded species in Abu-Za'abal Wetland (four lakes). It
aims also at analyzing the distribution pattern of the plant
species and the environmental factors that affect their
distribution. Forty stands were selected to represent the
apparent variation in the vegetation physiognomy and
habitats of these lakes. Sixty four species (38 annuals and
26 perennials) belonging to 56 genera and 28 families were
recorded in Abu-Za’able Wetland. Gramineae had the
highest contribution, followed by Leguminosae,
Amaranthaceae, Chenopodiaceae and Compositae. Forty-
POSTER ABSTRACTS
113
P36
five species (31 annuals and 14 perennials) were terrestrial
weeds, 7 species (2 annuals and 5 perennials) natural
plants, 6 species (one annual and 5 perennials) aquatic
weeds, while other six (5 annuals and one perennial)
escaped from cultivations. Life forms of the recorded
species indicated the predominance of therophytes,
followed by geophytes-helophytes, phanerophytes,
hemicryptophytes, chamaephytes and hydrophytes.
Pluriregional taxa were dominated over bioregional, and
monoregional ones. The dendrogram resulting from the
agglomerative clustering technique and DCA ordination of
the four lakes based on their floristic, soil and water
characteristics indicated that three clusters were separated:
cluster A includes lake IV, B includes lake I and C includes
lakes II and III. Lake I had the highest species diversity,
while lake IV had the lowest.
P36: 3
Growth of Phragmites australis in Lake Burullus, Egypt
Mohamed E.
Kafr El-Sheikh University, Egypt; [email protected]
Lake Burullus (Ramsar site in Egypt) is one of the Egyptian
northern lakes that connect with Mediterranean Sea through
one natural outlet. It has a total area of 410 km2, and has an
oblong shape extends for a distance of 47 km along NE SW axis. The main basin could be classified into 3 sections
(Eastern 117,6 km2, Middle 189 km2 and Western 103,4
km2). Lake Burullus is a shallow basin, its depth varies
between 40 cm near the shores and 200 cm near the sea
outlet; and contains 30 Islets (11 in Eastern sec., 15 in
Middle sec. and 4 in Western sec.).
Reed beds of Lake Burullus represent one of the most
important reed beds in the Mediterranean region; where this
type of habitat is becoming rare and threatened. Phragmites
australis recorded in the main habitats of Lake Burullus
area such as: salt marshes, sand sheets, lands cut from the
lake, terraces, slopes, water edges, open water zone of the
drains, lake shores, open water and islets
INDEX OF AUTHORS
Index of Authors
P = POSTER
L = PLENARY LECTURE
S = LECTURE SESSION
R = LAUREATION
LISASY = SATELLITE SYMPOSIUM: LICHENS
FOR ABSTRACTS OF L, S, R AND LYSASY
SEE “PROGRAM&ABSTRACT BOOK”
A
Abarzua, Sibylle
Abdaladze, Otar
Abdelly, Chedly
Abele, Analisa Daniela
Aberle-Malzahn, Nicole
Ache, Peter
Adamska, Iwona
Afshar zadeh, Saeed
Aguirre, Jesús
Ahmad, Rana Iqrar
Aker, Jose
Akhalkatsi, Maia
Akinnagbe, Akindele
Alaghehband, Negar - Hossein
alaghehband, negar-hossein
Al-Babili, Salim
Albach, Dirk C.
Albrecht, Sandra
Alder, Adrian
Allen, John
Altarejos, Alvin Alconcel
Altmann, Bianca
Altmann, Thomas
Alvarez, Miguel
Andersson, Ulrica
Andreev, I.
Andres, Sylvia
Angelova, Sornitza
Annick, Koulibaly
Appelhans, Marc
Appenroth, Klaus-J.
Arbeiter, Andrea
Arslan, Orhan
Asch, Folkard
Asiimwe, Theodore
Assefa-Fantaye, Chalie
Assmann, Sarah Mary
Ates, Mevlüde Alev
Augustin, Anna
Aurich, Claudia
Ayasse, Manfred
Ayoo, Linus Moses Kosambo
P31:15
P03:11
S01:3
P23:5
P13:1, P14:1
S34:5, P25:2
P18:33
P06:3
S22:1
P08:11
S31:2
P03:11
P01:5
P06:15
P06:7
P31:37, P31:9
S08:6
P22:13
P31:13
S20:4
P35:5
S27:4
S04:3
S21:4
P18:33
P19:1
P17:26
P32:16
S41:4
P26:11
P15:12, P13:11,
P18:20, P23:4
P22:21
P35:8
P19:6
P26:3
S16:4
L:7
P35:8
P16:1, P01:11
P03:12
S12:5, S30:2,
S30:1
P08:6
B
Baar, Kim-Miriam
Babbick, Maren
S24:5, P19:15
S16:5
Bacelar, Eunice
Bach, Thomas J.
Backhausen, Jan E.
Baden, Christian Ulrich
Bader, Maram
Bahulikar, Rahul
Baier, Margarete
Bailey-Serres, Julia
Balczun, Carsten
Baldwin, Andrew Hamilton
Balk, Janneke
Bals, Thomas
Balß, Jörg
Baluska, Frantisek
Baluška, František
Bamberg, Ernst
Barjaktarovic, Zarko
Barker, Nigel P.
Barniske, Anna-Magdalena
Barranco Medina, Sergio
Barranco-Medina, Sergio
Barsch, Aiko
Bartel, Stephanie
Bartels, Stephanie
Barth, Olaf
Barthlott, Wilhelm
Barton, Kathryn
Bartrina, Isabel
Bartsch, Oliver
Basché, Thomas
Batistic, Oliver
Bauch, Matthias
Baudisch, Bianca
Bauer, Franziska
Bauer, Joerg
Bauer, Robert
Baumann, Guido
Baumann, Ingrid
Baumann, Kim
Baumbach, Henryk
Baumeister, Dirk
Baumert, Alfred
Baur, Xaver
Bauwe, Hermann
Beck, Andreas
Beck, Erwin
Beck, W.
Becker, Annette
Becker, Burkhard
Becker, Dirk
Becker, Prof.Annette
Beckmann, Julia
Beer, Anja
Beerhues, Ludger
Behnke, Anke
Beining, Alice
Bekele, Endashaw
Belkheir, Asma k.
Bellmann, Birgit
Beneken, Christin
P18:8
P31:40
P30:3
P25:3
P08:6
P06:9
P30:12, P30:1,
S36:3
P20:1
P17:13
S21:1
S23:1, P17:35
P17:2
P13:19
S16:2
P09:1
S34:7, P13:4
S16:5
S38:3
P23:11
S39:4
S27:1
P15:9
P28:17
P21:2
P04:14
S41:2
S24:3
S47:1, P19:5
P18:18
P18:17
S09:4
P14:10
P17:9
S44:4
S07:2
P22:22
P17:27
P17:27
S03:2
P23:4
P13:31
P31:21
P08:2
S40:2, P18:18,
P18:19
lysasy:2
P19:11
P03:8
P04:5, P04:4,
P04:24
P06:17, P07:1
P17:30, P32:5,
S25:2, P08:11,
P08:6, P13:21,
P13:20, P08:5
P04:23
P18:24
S40:1
P31:27, P31:23,
P31:29
P14:7
S18:3
S41:3
P31:23
S31:1
P04:22
INDEX 115
INDEX OF AUTHORS
Benning, Christoph
Bentrup, Friedrich-Wilhelm
Benz, Philipp
Berendzen, Kenneth W.
Berg, Sabine
Berger, Susanne
Bergmann, Hans
Berina, Robert Soniel Navarte
Bernd, Mueller-Roeber
Bertalan, Ivo
Bertl, Adam
Beschow, Heidrun
Betsche, Thomas
Bettina, Falkenberg
Beyer, Peter
Beyhl, Diana
Bhattacharya, Debashish
Biastoff, Stefan
Biehl, Alexander
Bilger, Wolfgang
Binder, Stefan
Birkmann, Stefan
Bischof, Kai
Biskup, Bernhard
Bittkau, Christiane
Bittner, Cordula
Bittner, Florian
Blaschke, Hanna
Blattner, Frank R.
Blawid, Rosana
Bleeker, Walter
Blilou, Ikram
Blöchl, Andreas
Bock, Ralph
Boenigk, Jens
Boerjan, Wout
Boettinger, Petra
Bogner, Martin
Bohlmann, Holger
Bohne, Alexandra-Viola
Boland, Wilhelm
Bolle, Nina
Boller, Thomas
Bolte, Andreas
Bölter, Bettina
Bonfig, Katharina
Boniface, Kagiraneza
Bonilla, Oriel Herrera
Boos, Evelin
Borisjuk, Ljudmilla
Börner, Thomas
Borsch, Thomas
Boutry, Marc
Brach, Thorsten
Brachhold, Kerstin
Braeutigam, Andrea
Branco-Price, Cristina
Brand, Silke
Brändel, Markus
Brandt, Ronny
Brandt, Wolfgang
Bräuchler, Christian
116 INDEX
L:12
S34:7
S27:5
P20:11, P20:10
S10:2
P19:13, P04:11,
P30:9
P31:26
P35:5
S23:4
P14:9
P13:10, P13:20
P18:14
P15:9
S23:4
P31:39, S07:3
P13:20
S33:3, P17:33,
S33:2
P31:10
P18:32
P18:5, P18:22,
P06:14
S04:3, P15:1,
P17:5
P30:1
S13:3, P06:10,
P06:14, P06:4
P18:3
P28:11
P08:2
S47:4, P17:35
P19:8
S12:1, S19:7
S28:2
S08:3
L:9
P22:20, P22:12
P17:25
S13:5
S34:4
P08:7
P13:5
S22:3, P22:12
P17:25, S10:1
S11:2, L:4
P17:17, P17:37,
P17:15
L:3
S34:3
S27:5
P04:11, P22:15
P01:1
P10:2, P10:1
S08:4
S31:6
P17:12, P17:38,
P17:25, S10:1
P23:11, S41:3
S25:5
S36:2
P17:32
P13:15
P20:1
S05:2
P33:1
P13:11
P31:2
S38:5
Braun, Hans-Peter
Braun, Helen
Brauns, Jan
Bräutigam, Andrea
Bräutigam, Katharina
Breckle, Siegmar W.
Bremer, Melanie
Brennicke, Axel
Breuning, Stefanie
Briese, Volker
Brinker, M
Brinkmann, Henner
Brinkmann, Nicole
Brock, Andrea
Broer, Inge
Brosche, M
Broughton, Willam J
Brown, James
Brownlee, Colin
Bruckner, Christian
Brueckner, Kathleen
Bruhs, Anika
Büchel, Claudia
Buchert, Eva
Buchheim, Marcus
Buchhop, Jutta
Buchmann, Karin
Buck, Friedrich
Buckhout, Thomas J.
Bücking, Heike
Bull-Hereñu, Kester
Bültmann, Helga
Burger, Hannah
Burkhardt, Juergen
Bürstenbinder, Katharina
Busch, Andrea
Busch, Florian
Busch, Heinke
Busch, Susanne
Buschbom, Jutta
Büttner, Carmen
Büttner-Mainik, Annette
Bystriakova, Nadia
S04:4, S36:6
S47:1
S40:1
S46:4, P18:4
P18:32, S46:1,
P18:25
P10:1
P20:8
S04:1, P17:36
P15:6
P31:15
S44:3
P14:5
P14:7
P31:10
S15:4, P27:3
S44:3
S35:1
P13:7
S09:3
P06:9
P29:2
S27:4
S40:1, P14:3
P04:20
S09:5, P32:16
S42:3
P06:17
P30:10, S39:5,
P30:5, P13:12
S09:6
P26:6
P24:1
lysasy:6
S30:2
S18:3
P15:10
S03:3
P03:6
P03:5
S10:1
lysasy:4
S42:3
P08:8
S12:4
C
Cai, Daguang
Callis, Judy
Cam, Dilek
Camehl, Iris
Canino, Giusy
Carballo, Cristina Angela
Caron, Sébastien
Carpaneto, Armando
Cavalier-Smith, Thomas
Chapman, Anne Lise
Chase, Mark
Chen, Chung-Ying
Chincinska, Izabela
Cho, Won Kyong
Cho, Young Jun
Christian, Wiencke
Cin, Huriye
Cirpus, Petra
Claßen-Bockhoff, Regine
P22:2
S16:4
P35:8
P26:5
P17:39
P35:5
P03:6
P13:25
L-2
P03:2
S38:4
P04:18
P13:16
P17:10
P19:3
P06:16
P19:4
S07:2
P28:6, P24:1
INDEX OF AUTHORS
Claudel, Cyrille
Clauß, Kathleen
Coleman, Annette
Colmer, Timothy David
Comes, Hans Peter
Conk Dalay, Meltem
Convey, Peter
Corbet, Dominik
Correia, Carlos Manuel
Cortes, Claudio
Cosgrove, Daniel J.
Costa, Andrea
Costa, Liliana
Cozzolino, Salvatore
Crous, Pedro W.
Cunha, José Boaventura
Curtu, Alexandru Lucian
Czempinski, Nadine
P28:15
P31:21
S38:4, S33:1
S01:1
P28:11
P31:16
lysasy:4
S20:3
P18:8
P06:13
P22:12
S44:4
S02:1
S12:5
P22:22
P18:8
S19:5
S35:4
Dolnik, Christian
Domptail, Stephanie
Doobe, Gerhard
Döring, Elke
Dossahoua, Traoré
Dötterl, Stefan
P11:2
S16:3
S14:1
P23:12
P04:13
S39:3
P10:2
S48:3
S39:3
S26:3
S31:2
S35:1
S05:5
S01:3
S47:2, P08:8
S22:4, P22:17
S11:5, P03:9
S21:4
S22:1
S48:2
P32:7
P31:16
P31:25
S41:3
S41:3
P28:9
P01:4
P15:3, P32:9
P13:23
S41:4
S06:1
S02:1
P22:14
P13:13, P13:21
S39:4
P30:12, P13:28,
S27:3, P17:7,
P30:14, P13:30,
P30:6, P30:11,
S27:1, S36:3
P18:25
P25:8
S11:4, P25:3,
P25:7
P18:24
P13:32
E
D
Dähne, Judith
Daiker, Viktor
Daldrop, Peter
Dandekar, Thomas
Danisman, Selahattin
De Gara, Laura
de Oliveira Martins, Marcio
De Pauw, Eddy F
de Pinto1, C.
de Vera, Jean-Pierre
de Vries, Sacco C.
Deakin, William J
Debeaujon, Isabelle
Debez, Ahmed
Decker, Eva L.
Deeken, Rosalia
Degen, Bernd
Deil, Ulrich
Deising, Holger B.
del Barrio, Gabriel
Demir, Fatih
Demirel, Zeliha
DEMIREL, Zeliha
Demissew, Sebsebe
Denich, Manfred
Denk, Thomas
Derero, Abayneh
Desel, Christine
Desimone, Marcelo
Dethardt, Goetze
Dhonukshe, Pankaj
Dickinson, Hugh, Gordon
Diethelm, Manuela
Dietrich, Petra
Dietz, Karl Josef
Dietz, Karl-Josef
Dietzel, Lars
Dinse, Claudia
Dobler, Susanne
Doebbe, Anja
Dolan, Liam
Draeger, Birgit
Dreber, Niels
Dresselhaus, Thomas
Dreyer, Ingo
Dreyer, Jacqueline
Drincovich, María Fabiana
Drzewiecki, Corinna
Dückershoff, Katharina
Dueckershoff, Katharina
Dugall, Berndt
Dunkel, Elisabeth
Dunkel, Marcel
Durenkamp, Mark
Durner, Jörg
Ebele, Rainer
Ecke, Martin
Eckert, Christian
Edding, Mario, E.
Edelmann, Hans Georg
Edner, C.
Edner, Christoph
Eensalu, Eve
Efetova, Marina
Effmert, Uta
Egle, Komi
Ehlting, Barbara
Ehwald, Rudolf
Eing, Christian
Eisenhut, Marion
Eiserhardt, Wolf L.
Elles, Ingolf
Elleuche, Skander
Elling, Barbara
Ellinger, Dorothea
El-Sherif, Fadia
Emery, John
Endress, Peter K.
Endress, Peter Karl
Engelen, Andreas
Engelhardt, Ulrich H
Engels, Jana Gesina
Engqvist, Martin Karl
Ensminger, Ingo
Enß, Dagmar
Erdmann, Robert
Eriksson, Thorsten
Ernst, Oliver P.
Escalante Pérez, María
Escalante-Pérez, Maria
Essmann, Jutta
Esteves, S. M.
lysasy:5
S48:4
S11:6
P23:10, P23:1
S41:4
S30:3, S30:2,
P31:1
P31:10
P01:3
S31:1
P13:9, S44:5
P31:34
S46:3
P26:8
P19:13
P30:9
P11:2
P13:13
P17:30, P13:21
S23:5
S39:1
lysasy:1
P02:1
S09:4
P06:13
S06:2
P18:16
S46:2
S01:5
S22:4
P25:8
P18:14
S23:7
S21:2, S21:3,
P26:4
P13:20
S40:2
P28:12
P17:24, S20:2
P19:10
P21:1
P19:4
P08:1
S24:3
P24:2
S03:1
lysasy:4
S18:1
S21:6
P31:3
P03:6
P31:24
P20:3
S38:5
S14:1
P25:2
S34:5
P18:21, P18:27
P03:1
F
INDEX 117
INDEX OF AUTHORS
Fahnenstich, Holger
Falco, Virgílio
Falk, Jon
Fallahian, Fatollah
Faltusz, Alexander M. C.
Fatima, Tahira
Fayaz, P
Feike, Janie
Fekete, Ágnes
Fellenberg, Christin
Fernandez Lopez, Ángel B.
Fernández Núñez, Marta
Fernie, Alisdair
Ferreira, Helena
Fetene, Masresha
Feuerer, Tassilo
Feussner, Ivo
Fiala, Brigitte
Finckh, Manfred
Findling, Simone
Fink, Nadine
Finkeldey, Reiner
Finkemeier, Iris
Fischer, Andreas
Fischer, Dirk
Fischer, Irene
Fischer, Markus
Fischer, Matthias
Fischer, Uwe
FLADUNG, Matthias
Fladung, Matthias
Fladung, Matthias
Fleischmann, Frank
Floß, Daniela S.
Flowers, Timothy John
Flügge, U.I.
Flügge, Ulf Ingo
Flügge, Ulf-Ingo
Formann, Steffi
Forner, Joachim
Frahm, Jan-Peter
Francke, Wittko
Frank, Julia
Frank, Wolfgang
Franke, Stephanie
Fredersdorf, Jana
Freystein, Katharina
Fricke, Anna
Frieder, Müller-Uri
Friedl, T.
Friedl, Thomas
Friedt, Wolfgang
Friehe, Sven
Friesen, Nikolai
Friml, Jiri
Frischmuth, Sabine
Fritz, Michael
Fromm, J
Fromm, Jörg
Fromm, jörg
Frommolt, Ruth
Frühwald, Arno
Fry, Stephen C
118 INDEX
S46:3
P18:8
P29:2
P06:3
S09:3
P04:11
S44:3
P20:7, P31:35
S35:3
P31:38
S12:3
P19:8
P18:32
P18:8
S18:3
P12:3
S35:4
S19:7
P16:1, P01:11
P32:9
P06:2
P33:4, P01:5,
S19:5, P01:4
P30:6, R:3
S37:4
P08:4
P03:5
S30:4
S14:4
P04:19
P08:1
S15:2, P20:5,
P03:7
P03:9, P08:5,
P03:3, P03:4
S34:2
P26:2, P31:32
S01:1
P31:3
P32:8
P13:23, S46:3,
S15:3, P13:14
P26:3
S04:3
P23:6
S12:5
P20:6
S09:3, S24:5,
P19:15
P13:11
P06:10
P06:12
P03:2
P31:19
P14:8
P06:8, S33:6,
P14:7, P07:3
P22:14
P04:17
P28:7
S06:1
S28:1
S21:2, S21:3
P13:29
S34:6
P25:2
S33:3
S34:1
P29:4
Fuchs, Ines
Fuchsberger, Kai
Fuehrs, Hendrik
Funk, Helena T.
P32:7
P19:11
S36:6
S10:2
G
Gabriele, Fischer
Gadaleta, C.
Gagneul, David
Gailing, Oliver
Galal, Tarek M
Galfe, Nadine
Galinha, Carla
Galinsky, Ina
Gamas, Pascal
Garab, Győző
Garcia, Monica
Gau, Achim
Gau, Achim E.
Gebert, Marina
Gebhardt, Manuela
Gebhardt, Yvonne
Gebühr, Christina
Gehrke, Berit
Geigenberger, Peter
Geiger, Dietmar
Geiger, Michael
Geimer, Simon
Geipel, Gerhard
Geissler, Nicole
Geißler, Nicole
Geißler, René
Gemeinholzer, Birgit
Gent, Ricardo
Gerendas, Joska
Gerendás, Jóska
Gerlitz, Nadja
Gershenzon, Jonathan
Ghergel, Felicia
Gibon, Yves
Gielis, johan
Gigolashvili, T.
Gladis, Franziska
Glaeser, Judith
Glanz, Stephanie
Glawischnig, Erich
Glöckner, Gernot
Go, Crystal Karen Ong
Göbel, Cornelia
Gobert, Anthony
Godiard, Laurence
Goetze, Stefanie
Gögler, Julia
Göker, Markus
Golczyk, Hieronim
Goldbach, Heiner E.
Golecki, Jochen
Golldack, Dortje
Gomez-Porras, Judith Lucia
Gonçalves, Berta
Gontcharov, Andrey
Gonzalez, Mari-Cruz
González-Rodríguez, Agueda
Göpfert, Jens
P31:19
S39:3
S14:3, S46:4,
P18:4
P33:4, P01:5,
S19:5, P01:4
S21:5, P36:2
P22:21
L:9
S12:3
S35:5
P18:10
S48:2
P04:6
P22:16, P22:11
S10:3, S31:1
P13:31
P31:17
P13:1
S38:5
P18:32, L:11
P13:25, S25:2
S07:2
P17:10
P32:13
P10:3
S01:4
P31:28
P28:8
S07:1
P15:3
S18:2, P15:6
S31:5, P18:1
P15:1
P26:3
L:11
S03:4
P31:3
P06:6
S21:7
P17:13
P31:30, P19:16
S33:5, P07:1
P35:5
S35:4
S25:1
S35:5
S36:6
S12:5
S19:4
S19:6
S18:3
S10:6
P13:28, P13:30
S44:5
P18:8
P07:2
P04:11
S12:3
P31:18
INDEX OF AUTHORS
Goss, Reimund
Goss, Tatjana
Göttfert, Michael
Göttling, Melanie
Götz, Christine
Götz, Klaus-Peter
Götze, Stefanie
Govers, Kim
Grabov, Alexander
Grabowski, Evelyn
Graf, Alexander
Graff, Alexandra
Grams, Thorsten
Grauvogel, Carina
Grein, Michaela
Greiner, Stephan
Greiten, Christian
Grieneisen, Veronica
Griesser, Michaela
Grigoriev, Pavel A.
Grimm, Bernhard
Grimm, Guido W.
Groenewald, Johannes Z.
Grond, Stephanie
Gross-Hardt, Rita
Grossman, Arthur R.
Grossniklaus, Ueli
Groth-Malonek, Milena
Grube, Esther
Grube, Martin
Gruber, Ansgar
Gruber, Henriette
Grundler, Florian M. W.
Grundler, Florian M.W.
Grundmann, Götz
Guicking, Daniela
Guinot, David
Gundermann, Kathi
Gundlach, Kristina
Günther, Björn
Guo, Shiwei
Guo, Xiaomei
Gustavs, Lydia
Gutensohn, Michael
Gutierrez-Marcos, Jose
S33:3, P18:10
P30:13
S35:2
S11:4
S35:3
P15:8, P08:9
P32:4
S41:3
P13:32
P17:8
S22:1
P33:2
S34:2
P14:5
P18:6
S19:6
S15:3
L:9
S22:3
S11:2
P13:16
P28:9, S19:4,
P28:13
P22:22
S35:4
S31:4, P20:4
S33:3
S31:4
P05:1
P13:23
S26:1
S27:2, P13:27,
P14:3, P17:23
P32:1
P22:12
S22:3
P18:17
S19:7
P13:13
S40:1
P18:17
P03:7
P15:3
P22:3
P06:8
P17:6, P17:22
S02:1
H
Haase, Winfried
Häberle, Karl-Heinz
Häder, Donat-Peter
Haebel, Sophie
Haferkamp, Ilka
Haferkamp, Silvia
Hagemann, Martin
Hager, Johannes
Hahn, Achim
Halim, Jamilah
Hallmann, Armin
Hallmann, Christine
Hameister, Steffen
Hammer, Timo
Hammer, Timo R.
Hampp, Rüdiger
P18:28
S34:2
S16:3
P17:27
S15:3
P18:28, S20:4
S40:2, P08:10,
P18:18
P10:1
S06:2
P36:1
P04:2, P04:16
S33:6, P07:3
P28:1
P22:7
P22:10
S16:5
Hampp, Ruediger
Hanelt, Dieter
Hanitzsch, Miriam
Hanner, Peter
Hans, Joachim
Hänsch, Robert
Hansen, Ulf-Peter
Hanson, Dave
Hanspach, Jan
Hänßgen, Ilka
Härdter, Rolf
Hartard, Britta
Harter, Klaus
Hartig, Katja
Hartl, Lorenz
Hartmann, Anton
Hartmann, Heidrun E.K.
Hartung, Frank
Hasenstein, Karl H.
Haszprunar, Gerhard
Hatzopoulos, Polydefkis
Hauck, Markus
Hauer, Rene
Hause, Bettina
Hauser, Andreas
Hauser, Felix
Häusler, Rainer E.
Hawighorst, Peter
He, Hongxia
Hedrich, R
Hedrich, Rainer
Hedtke, Boris
Hegemann, Peter
Heiber, Isabelle
Heidstra, Renze
Heilmann, Ingo
Heinlein, Manfred
Heinrichs, Jochen
Heinz, Ernst
Heinze, Michael
Hell, Rüdiger
Helle, Gerhard
Hellwig, Frank
Hellwig, Frank H.
Hellwig, Frank. H.
Hemleben, Vera
Hemmerlin, Andrea M.
Hendriks, Janneke
Hennecke, Hauke
Herl, Vanessa
Hermann, Katrin
Herold, Miriam
Herppich, Werner B.
Herrmann, Markus
Herrmann, Reinhold G.
Hertel, Brigitte
P26:10
P06:18, P03:4
P13:30
P17:31
S05:3, P31:8
S23:3, P15:11
S25:3, P15:3
S14:4
S08:4
P14:2
S18:2
?:1
P20:11, P20:2,
P20:10, S09:1
P19:11
P22:14
S35:3
P01:10
P33:5
S16:1
P28:8
P13:32
S26:4
P17:16
S35:7, P19:9,
P19:12, P31:38,
P26:12
P13:26
S35:2
S15:3
S01:5
P13:16
P13:29
P32:12, S06:5,
P13:25, P17:30,
P32:5, S22:4,
S25:2, S34:5,
P32:7, P32:15,
P25:2, P13:21,
P13:20, P32:2,
P22:17
P17:38
P13:4, S14:1
P30:12, S36:3
L:9
S37:3, P17:28,
P19:7, S31:3,
P04:8
S42:2
S17:5
P22:13, S07:2
S09:5, P32:11
S36:2, S23:2
P03:7
P23:4
P23:7, P01:9
P28:2
P28:9, S19:4,
P28:13
P31:40
L:11
S35:2
P31:19
P04:19
S35:6
S01:2
P04:21, P04:20
S19:6, S20:5
S28:3, P13:31
INDEX 119
INDEX OF AUTHORS
Hertel, Stefanie
Herwig, Stefan
Hesse, Holger
Heubl, Günther
Heydel, Felix
Heyser, Wolfgang
Hieke, Margit
Hilgarth, EM
Hilker, Monika
Hillig, Inga
Hiltscher, Heiko
Hinrichsen, Inga
Hippauf, Frank
Hoef-Emden, Kerstin
Hoenicka, Hans
Hoff, Birgit
Hoffman, M Timm
Hoffman, Timm
Hoffmann, Anne
Hoffmann, Manuela
Hoffmann, Matthias H.
Hoffmann, Ralf
Hoffmann-Benning, Susanne
Hofhuis, Hugo
Hofmann, Alexandrine
Hofmann, Julia
Hogeweg, Paulien
Hohenstatt, Mareike L.
Holländer-Czytko, Heike
Hölscher, Dirk
Holtgrefe, Simone
Hölzle, Angela
Holzwarth, Alfred
Homann, Ulrike
Hönicka, Hans
Hönicka, Hans
Hopff, David
Hoppert, Michael
Hoque, Imdadul
Horbach, Ralf
Horn, Cornelia
Horst, Walter Johannes
Hossain, Md. Zakir
Hossain, Mohammad B.
Huber, Christian
Huchzermeyer, Bernhard
Hude, Rene
Huecherig, Stephanie
Huesgen, Pitter Florian
Humbeck, Klaus
Hummel, Sabine
Humphreys, Aelys M.
Hundt, Miriam
Hüner, Norman PA
Hupp, Sabrina
Hurka, Herbert
Hurst, Annette C.
Hüser, Anke Christine
Huskens-Keil, Susanne
Huss, Volker
Hussin, Sayed
Hust, Bianca
Huynen, Martijn A.
Hwang, In-yong
120 INDEX
P19:14
P14:11
S23:4
S38:5
P28:3
P26:6
S09:5
P13:29
S11:1
P22:13
P30:12
P17:37
P20:7
P07:4
P03:4
P31:34
S41:5
S41:1
P15:3
P17:11
S38:2
P18:10
P13:15
L:9
P22:18
P22:20, S22:3,
P22:12
L:9
P20:11
P15:4
S05:2
S27:4, S36:5,
P32:21, P30:3
S04:3
S20:5
P13:8
P08:1
P03:3
P30:5
P07:3
P22:8, S18:5
S22:1
P19:19
S36:6
P19:9
P22:16
P17:26
S01:3
P13:10
P31:31
P18:33
P04:14
P20:11
S38:3, P23:13
P31:7
P03:6
P22:15
S19:3, P28:5,
P28:4
P13:8
P32:8
S01:2
P06:2
P10:3
P17:6
P13:22
P19:3, P19:16,
P04:3
I,J
Ibisch, Pierre L.
Ick, Julia
Ilg, Andrea
Imhof, Stephan
Isabell, Witt
Ischebeck, Till
Jacob, Simone
Jahn, Regine
Jakob, Torsten
Jamalloo, fatemeh
Jander, Vanessa
Janowiak, Franciszek
Janska, Hanna
Janssen, Friederike
Janssen, Thomas
Jansson, Christer
Janz, D
Jaros, Ursula
Jaspert, Nina
Jauneau, Alain
Jensen, Kai
Jeske, Holger
Jeworutzki, Elenea
Jiménez, M. Soledad
Jockovic, Nebojsa
Johanningmeier, Udo
Jones, Alan M.
Jonietz, Christian
Joost, Regina
Jörg, Meurer
Jülke, Sabine
Jung, Christian
Jürgens, Andreas
Jürgens, Gerd
Jürgens, Norbert
P28:10
S44:2
P31:13
P26:11, P01:6,
P26:9, P31:1
S23:4
S31:3, P04:8
P30:6
P14:7
P06:1
P06:7, P06:15
S47:4
P19:6
P17:19
P17:22
S12:4
P20:2
S44:3
P28:11
S25:5, P18:2
S35:5
S21:6, P33:1,
P28:3
S28:1
P32:5
S12:3
P31:10
P08:4, P14:6,
P14:2, P14:9
S16:4
S04:3
S27:4
S19:6
S47:2, P22:9
L:6
S30:3
L:10
S48:5
K
Kadioglu, Asim
Kadow, D.
Kadow, Daniel
Kägi, Christina
Kahmen, Ansgar
Kai, Bischof
Kai, Marco
Kaiser, Hartmut
Kaiser, Heike
Kaiser, Roland
Kaiser, Werner M.
Kaldenhoff, Ralf
Kalko, Elisabeth
Kaminski, Marc
Kandlbinder, Andrea
Kangasjärvi, J
Kaplan, Aaron
Kapuganti, Jagadis Gupta
Karabay Yavasoglu N.Ülkü
Kärkönen, Anna
Karlova, Rumyana
Karlovsky, Petr
P29:3
P35:1
P35:6
S31:4
R:1
P06:16
S22:5
P15:3, P32:19
P31:10
P26:12
P22:1
S14:4
S30:4
S40:3
P17:7, S27:1
S44:3
S40:2
P22:1
P31:16, P31:25
P29:4
S31:2
S35:4, P19:18
INDEX OF AUTHORS
Karsten, Ulf
Kasambula, Phyllis G.
Kasperek, Gerwin
Kast, Stefan M.
Kaulfürst-Soboll, Heidi
Keding, Gudrun B.
Kehr, Julia
Kellner, Alexandra
Kellner, Sandra
Kempken, Frank
Kerp, Hans
Kessler, Michael
Khalafallah, Ahmed A.
Khan, Muhammad Sayyar
Khawar, Khalid Mohmood
Khraiwesh, Basel
Kianianmomeni, Arash
Kiehlmann, Elke
Kilbienski, Isabell
Kilian, Joachim
Kim, Yeo-jae
Kirchberger, Simon
Kirchhoff, Helmut
Kirschner, Roland
Klaas, Christine
Klähn, Stephan
Klein, Marion
Klein, Markus
Klein, Peter
Kleine, Michael
Kleine, Tatjana
Kleine-Vehn, Jürgen
Kleinow, Tatjana
Klinkenberg, Jörn
Klinkert, Birgit
Klode, Mathias
Kloer, Daniel Paul
Klose, Cornelia
Klösgen, Ralf Bernd
Klotz, Stefan
Kluth, Jantjeline
Knill, Tanja
Knoop, Volker
Knüfer, Jessica
Koch, Martina
Köhler, Barbara
Köhler, Daniela
Köhnen, Ines
Koiwa, Hisashi
Kolbe, Ludger
Köllmer, Ireen
Kolukisaoglu, Üner
Komarova, Nataliya
König, Nicolas
König, Sabine
Konrad, Kai Robert
Konrad, Kai-Robert
Konrad, Wilfried
Kopertekh, Lilya
Kopka, Bernd
Kopka, Joachim
P06:8, S13:4,
P06:6, P06:11,
S33:6, P06:10,
P07:3
P01:1
P11:2
P13:31
P20:6
P01:1, P01:2
P22:19
P01:9
S05:3
P17:17, P17:37,
P22:4, P17:15
S17:1
S12:2
P36:2
S23:2
P35:8
S24:5
P04:2, P04:16
S12:6
P17:8
P20:11, P20:2,
P20:10
P19:2, P04:3
P13:22
P18:28, S20:4
P22:6
P14:1
P08:10
P31:36
S05:5
P30:1
S07:4
P18:12
S06:1
S28:1
P22:17
P14:12
P27:2
P31:9
S06:4, P32:6
P17:22, P17:16,
P17:11, P17:9
S08:2, S08:4
S10:3, P04:21,
P04:20
P15:1
P05:1, P17:34
P14:11
S22:7
P13:6
P17:5
S19:2
P20:6
S05:4
S47:1
P20:11, P20:2
P28:13
S27:4
P17:28, P19:7,
P04:8
P32:12
P32:15
S17:2
P27:3
S01:5
S36:6
Kopriva, Stanislav
Koprivova, Anna
Kopycki, Jakub Grzegorz
Kornberger, Wolfgang
Kothe, Erika
Kötting, Oliver
Koutb, Mostafa
Kovaleva, L.
Kovaleva, Lidia Valentinovna
Kowarik, Ingo
Koyro, Hans-Werner
Krabel, Doris
Kraberg, Alexandra
Kraft, Christine
Kranz, Erhard
Krause, Katrin
Krause, Kirsten
Krebs, Melanie
Krebs, Michael
Krech, Katharina
Kreft, Holger
Kreier, Hans-Peter
Kreil, David P.
Kreimer, Georg
Kreis, Wolfgang
Krenz, Björn
Kretsch, Thomas
Kriebitzsch, W.-U.
Kriechbaumer, Verena
Krieger, Alexander
Krijger, Jorrit-Jan
Krohn, Katrin
Kroth, Peter
Krug, Rainer M
Krügel, Undine
Krumpe, Katrin
Krupinska, Karin
Kruse, Karoline
Kruse, Olaf
Kubigsteltig, Ines
Kubitscheck, Ulrich
Kuchernig, Jennifer
Kück, Ulrich
Kudla, Jörg
Kufa, Taye
Kühdorf, Katja
Kühle, Susanne
Kühn, Christina
Kühn, Ingolf
Kühn, Kristina
Kuijpers, Anne-Marie
Kukavica, Biljana
Kulmann, Christoph
Kumwenda, Rose
Kunze, Irene
Küper, Wolfgang
Küpper, Hendrik
Küppers, Manfred
Küster, Helge
Kutschmar, Anke
S23:5
S23:5
P31:5
S23:7
P26:3
S46:2
P04:6
P19:1
P33:3
S08:5
P10:3, S01:3,
S01:4
P03:7
P14:1
P06:2
P33:2
P26:3
S10:2
P13:5, S25:4
P14:9
P18:12
S41:2
S12:2
P22:12
S40:3, P14:10
P31:19
S28:1
S06:4, P32:6
P03:8
P19:16
P32:20
S22:1
P20:7
P06:9, S27:2,
P18:23, P13:27,
P14:3, P17:23
S41:5
P13:16
P17:19
S10:2, P17:8,
P17:14, P18:5,
P29:2
S10:3
S20:2, P18:24
P19:4
P09:1, S16:2
P15:11
P04:1, P31:34,
P17:13, S10:4
S09:4
S18:3
P23:4
P31:27
P13:16
S08:2, S08:4
P17:25, S10:1
S07:2
P29:1
P26:6
P01:1
S07:2
S41:2
P18:29, P13:3,
P18:9
?:2
P08:9
S47:5
INDEX 121
INDEX OF AUTHORS
L
Labandeira, Conrad C.
Lachmann, Nicole
Lachnit, Tim
Ladig, Roman
Lakatos, Michael
Lamparter, Tilman
Lang, Christina
Lang, Daniel
Lang, Kathrin
Lange, Henrik
Lange, Matthias
Lange, Peter Robert
Lange, Sabrina
Lange, Theo
Langenkämper, Georg
Langner, Uwe
Larisch, Christina
Laschke, Corinna
Latz, Andreas
Laurent, Aké Assi
Lautner, Silke Christine
Lavaud, Johann
Laxa, Miriam
Lazaro Paniagua, Juan Jose
Le Quéré, Antoine
Lebaudy, Anne
Lebert, Michael
Lee, Justin
Lee, Young Na
Lefebvre, Benoit
Leffers, Hans-Martin
Legen, Julia
Legner, Nicole
Lehmann, Gabriele
Lehmann, Thomas
Lehnhardt, Lothar
Lehr, Nina
Lehr, Nina Alexandra
Leister, Dario
Leitenmaier, Barbara
Leitner, Margit
Leljac-Levanic, Dunja
Lembcke, Sebastian
Lendzion, Jasmin
Lepetit, Bernard
Lerchl, Jens
Leroch, Michaela
Leubner, Gerhard
Leuchte, Jessica
Leuschner, Christoph
Ley, Alexandra
Lezhneva, Lina
Li, Hsi-Wen
Li, Jie
Lieberei, R.
Lieberei, Reinhard
Liede-Schumann, Sigrid
Liere, Karsten
Lindemann, Andrea
Linder, H. Peter
122 INDEX
P31:1
P17:35
S13:3
P17:22
S43:2
S06:3, P32:20
S23:3
S44:2
S35:2
P03:10
P04:4
P31:38
P04:23, P04:24
S37:4
P15:9, P22:18
P18:31
S34:5
S19:3, P28:5,
P28:4
P17:30, P13:20
S41:4
S34:6
S13:2, P18:23
P17:7, P30:11,
S27:1
S39:4
S35:1
P13:9
S16:3
P13:21
P19:3, P19:16,
P04:3
S35:5
P28:4
S20:5
P32:19
S01:5
P19:10, P19:17
P17:27
P26:10
S35:6
P18:32, S20:1
P18:29, P13:3
P26:12
S31:1
P06:8
P19:18
P18:10
S15:1
P13:22
P04:19
P31:32
P19:18
P28:6
P17:10
P23:8
P23:8
P35:1
P35:6, P35:3,
P31:12, P35:4
P01:8, S30:3
P17:12, P17:38,
P17:25, S10:1
S35:2
S38:3, P23:13
Linder, Hans Peter
Lindermayr, Christian
Link, Gerhard
Linka, Marc
Linka, Nicole
Linke, Bettina
Linke, Vera
Linkies, Ada
Linsenmair, K. Eduard
Lischewski, Sandra
Liu, Cuimin
Liu, Tzu-Yin
Lobbes, Dajana
Locato, V.
Löder, Martin
Lodha, Mukesh
Lohmann, Jan U.
Lohr, Martin
Lohscheider, Jens Nikolaus
Looser, Jens
Lorbiecke, René
Loris, Kurt
Lörz, Horst
Loschelder, Heike
Löser, Carsten
Lückmann, Katrin
Ludenberg, Inga
Ludewig, Frank
Ludewig, Uwe
Ludwig-Müller, Jutta
Lughofer, Peter
Luijten, Marijn
Lundberg, Magnus
Lunn, John
Lüthen, Hartwig
Lüthje, Sabine
Lyubenova, Lyudmila
S19:1
S36:5, S39:1
P04:10, P04:15
S14:3, P17:33,
S46:4, P18:4
P13:24, S14:3,
S46:4, P18:4
P04:18
P32:21, P30:13
P04:19
S30:4
P19:12
S10:6
S25:4
P04:7
S39:3
P14:1
S40:4
L:8
S33:3, P14:10,
P14:3, P14:11
P18:33
P13:4, P32:10
S10:3, P04:21,
P04:20, P04:22
S46:3, S26:2
P08:11, P08:6,
P08:5
P04:10, P04:15
P23:7, P28:2
P28:5
P27:1
S15:3, P32:8
P13:5
S37:2, S47:2,
P22:9, P19:19,
P26:1, P22:19
P13:10
L:9
S38:5
L:11
P32:3
P30:10, S39:5,
P30:5, P29:1,
P13:12
P29:5
M
Maass, Brigitte L.
Maaß, Dirk
Machackova, Ivana
MacKay, John
Magel, Elisabeth
Magel, Elisabeth A.
Máguas, Cristina
Mahfoud, Hafez
Maier, Frank J.
Maier, Uwe G.
Maischak, Heiko
Maiss, Edgar
Major, Istvan
Manavski, Nikolay
Mangelsen, Elke
Marandu, Wilson
Marazzi, Brigitte
Marchfelder, Anita
P01:1, P01:2
P31:39
P04:19
P03:6
P03:10
P03:5
S43:2
P23:9
S22:2
S10:2, S33:3
S11:2
S28:2, S42:4
P10:2
P08:2
P20:2
P01:1
P24:2
P17:39
INDEX OF AUTHORS
Marco, Sergio
Maréchal-Drouard, Laurence
Maria Inés, Zanor
Marin, Birger
Marin, Kay
Marinova, Krasimira
Markussen, Torsten
Marquardt, Daniel
Marques, E. M.
Marten, Holger
Marten, I
Marten, Irene
Martens, Stefan
Martin, Cathie
Martins, Rui
Marty, Laurent
Masloff, Sandra
Masselter, Tom
Matern, Ulrich
Materna, Arne
Matthäi, Kevin
Matthes, Annemarie
Matthijs, Hans C. P.
Matyssek, Rainer
Maurino, Verónica G.
Maurino, Verónica Graciela
Mayer, Jorge E.
Mazars, Christian
McDowell, Nate
Mecklenburg, Rainer
Meeßen, Joachim
Mehrani Adl, Maryam
Mehrani adl, maryam
Meier, Anna-Carolin
Meiners, Torsten
Meinhard, Juliane
Melkonian, Michael
Melonek, Joanna
Melzer, Rainer
Menckhoff, Ljiljana
Mendel, Ralf R.
Mendel, Ralf-R.
Menkhaus, Jan
Merbach, Wolfgang
Meurer, Jörg
Meve, Ulrich
Meyer, Andreas J.
Meyer, Matthias
Meyer, Rhonda C
Meyer, Stephanie
Meyer, Tanja
Mezher, Zeina
Miao, Ying
Michalski, Carmen
Michalski, Justyna
Michel, Klaus Peter
Michel, Klaus-Peter
Mielke, Nicole
Mika, Angela
Mikolajewski, Sabine
Mikosch, Melanie
S25:5
S04:2
S23:4
P07:2, S33:5
P08:10
S05:5
P20:5, P03:7,
P03:9
P08:10, P13:14
P03:1
P32:12, S06:5
P13:29
P13:20
P31:17, P31:6,
P31:7
S03:2
P18:8
S36:2
P22:18
S17:3
S05:3, P31:17,
P31:8, P31:6,
P31:7
P17:23
P30:7
P17:5
S40:2
S34:2
S46:3
P13:23
S44:5
S47:3
S14:4
P23:7
?:14
P06:7
P06:15
P31:10
S11:1
P04:19
P07:2, P17:32,
S33:5
P17:14
S24:4
P30:10, P29:1
S47:4, P17:35
, P15:11
P22:2
P18:14
S20:5, P17:10
P01:8, S30:3
S36:2, S23:2
P03:7
S04:3
P15:11, S02:3,
P04:9
P17:20
P18:15
P17:8
P25:1
L:11
P15:7
P18:11, P30:4,
P15:2
S42:1, P27:2,
P27:1
S39:5
P22:14
P13:8
Mikschofsky, Heike
Milde, Sabine
Milkowski, Carsten
Minkina, Y.
Minkina, Yuliya Viktorovna
Mira-Rodado, Virtudes
Mirzabagheri, Dawood
Miszalski, Zbigniew
Mithoefer, Axel
Mithöfer, Axel
Mittag, Maria
Mohagheghi, Hoda
Mohamed, Ebrahem Mohamed Eid
Mohd Salim
Mohr, K. I.
Molina, Isabel
Molis, Markus
Moll, Cordula
Møller, Ian Max
Mollwo, Anne
Mongrand, Sébastien
Montanini, Barbara
Moore, Robert
Morales, Domingo
Moreau, Sandra
Moreira, Cármen
Morel, Johanne
Moreth, Ute
Moroni, Anna
Mosblech, Alina
Motyka, Václav
Moustafa, Ahmed
Movahedi Naini, Zahra
Mrosk, Cornelia
Mudimu, Opayi
Muehlbach, Hans-Peter
Mueller, Martin
Mueller, Stefan
Mueller-Roeber, Bernd
Muellner, Alexandra Nora
Mühlbach, Hans-Peter
Mühlhausen, Andreas
Mühling, Karl H.
Mukherjee, Oindrilla
Mulisch, Maria
Müllen, Klaus
Müller, Daniela
Müller, Kai
Müller, Katja
Müller, Kerstin
Müller, Lenard
Müller, Maren
Müller, Martin J
Müller, Rebecca
Müller, Ruth
Müller, Stefan
Müller, Tobias
Mullineaux, Conrad
Mumm, P
Mummenhoff, Klaus
Muñoz, Jésus
Murray, Shauna Ann
Mussgnug, Jan H.
Mustroph, Angelika
Muthreich, Martin
Mutke, Jens
Mutterer, Jérôme
S15:4
P15:3
P31:21, P31:38
P19:1
P33:3
S09:1
P35:7, P35:2
P18:5
P25:5
S47:3, S11:2,
P26:12
S40:3, S40:5
P25:1
P36:3
P36:1
P14:8
P32:20
P06:18, P03:2
S31:4
S36:4
S40:3, P14:10
S36:1
S25:1
P07:6
S12:3
S35:5
P18:8
S36:1
P03:5
S28:3, P13:31
P17:28, P19:7
P19:8
S33:2
P06:3
S35:7
S33:6, P07:3
S42:1, P27:1
P30:9
P30:9
P13:6, S44:5
S38:4
P22:8, P27:2
P04:7
P15:6
P22:21
P17:8
P18:17
P27:2
P23:11
P13:6
P04:19
P17:14
P21:1
P19:13
S06:4
P06:16
P19:13
P23:12
P18:28, S20:4
P13:29
P04:7
S44:4
P07:6
S20:2
P20:1
P15:4
S41:2
P31:40
INDEX 123
INDEX OF AUTHORS
N
Nagel, Georg
Nakhutsrishvili, George
Nam, Myung Hee
NAR, Hatice
Narberhaus, Ingo
Naumann, Kai
Neinhuis, Christoph
Nejadsattari, Taher
Nematollahi, Ghazaleh
Neu, Daniel
Neuffer, Barbara
Neuhaus, Ekkehard
Neuhaus, H. Ekkehard
Ng Chin Yue, Sabine
Nichelmann, Lars
Nichols, John
Nickelsen, Jörg
Nickelsen, Kärin
Niebel, Andreas
Niehaus, Karsten
Niemanak, N.
Niesler, Ingeborg Maria
Niewiadomska, Ewa
Nodop, Anke
Nosenko, Tetyana
Novak, Ondrej
Novoa, Patricio
Novoisky, Janine
Nowack, Eva C.M.
Nowrousian, Minou
Nuppenau, Ernst-August
Nykytenko, Alla
P13:4, P32:10
P03:11
P04:3
P29:3
S11:4
P31:28
S44:4, P23:9,
P23:6
P06:3, P06:7,
P06:15
P04:2, P04:16
P19:10, P19:17
P21:1, S19:3,
P28:1, P28:5,
P28:4
P13:24
S15:3, P13:22
P18:23
P18:22
S03:2
P17:24, S20:2,
P14:12
S45:1
S35:5
P15:9
P35:1
P01:10
P18:5
P18:13
S33:2
P19:8
S12:6
P14:11
S33:5
P04:1
S48:4
S46:1
O
Ober, Dietrich
Obermeyer, Gerhard
Oberpichler, Inga
Oecking, Claudia
Oelkers, Margit
Oelmüller, Ralf
Oelze, Marie-Luise
Oh, Young Joo
Ohad, Itzhak
Oliver, Sandra
Orashakova, Svetlana Ivanova
Ossenbühl, Friedrich
Oßwald, Wolfgang
Osuna, Daniel
Otmar, Spring
Ott, Sieglinde
Ott, Thomas
124 INDEX
S11:3, P31:24,
P25:1
P13:17, P13:10
S06:3, P32:20
S25:5, P20:9,
P18:2, P20:4
P15:11
P26:5, P26:8,
P26:1, R:2
P30:14
P19:3, P19:16,
P19:2, P04:3
S20:5
P18:32
P04:5
P17:18, P17:3,
P17:29
S34:2
L:11
P31:18
lysasy:1, S26:3,
lysasy:4
S35:5
Ottmann, Christian
Otto, Beate
Otto, Elisabeth Maria
Özdemir, Funda
Ozdemir, Guven
Ozdemir, Güven
Özel, Cigdem Alev
S25:5
S14:4
P28:16
P35:8
P31:16
P31:25
P35:8
P
Paetzold, Heike
Pakull, Birte
Palmieri, Cristina
Panes, Vivian Arque
Pannell, Caroline
Papenbrock, Jutta
Parameswaran, Aravind
Park, Woong June
Parolin, Pia
Pasternak, Maciej
Paulsen, Harald
Pawlowski, Katharina
Pedas, Pai
Peiter, Edgar
Peneva, Kalina
Pereira, José Moutinho
Pereira, R. A. S.
Perez-Rodriguez, Maria
Perry, Paula Jay
Persoh, Derek
Pertl, Heidi
Pescheck, Frauke
Peters, Jule
Petersen, Jörn
Petersen, Maike
Petschenka, Georg
Pfannschmidt, Thomas
Pfiz, Michael
Philippi, Nicole
Phoris, Carina
Picques, Maria
Piechulla, Birgit
Piekenhayn, Susanne
Pienkny, Silke
Pietsch, Daniel
Pimenta Lange, Maria Joao
Pinto, Sheena
Piotrowski, Markus
Pirie, Michael D.
Pirie, Michael David
Pischtschan, Elke
Pistorius, Elfriede K.
Plieth, Christoph
Pöckl, Magdalena
Pohanke, Judith
Pohl, D.
Pohnert, Georg
P31:32, P31:4
P20:5
S39:1
P35:5
S38:4
P31:36, P15:5
P18:29, P13:3
P19:3, P19:16,
P19:2, P04:3
P21:2, P28:17
S36:2
S33:3, P14:3,
P18:17
S35:4
S25:1
S25:1
P18:17
P18:8
P03:1
S03:2
P04:18
?:8
P13:17
P06:14
P28:10
S33:4, P14:5
P31:33, P31:14
P25:7
P18:32, S46:1,
P30:8, P18:25,
P30:7
S46:3, S26:2
P23:12
P26:9
L:11
S22:5, P20:7,
P31:15, P31:35,
P25:8
P17:18, P17:3,
P17:29
P31:2
P18:11, P30:4
S37:4
P04:21, P04:20
S23:6, P22:16,
P18:2, P25:5
P23:13
S38:3
P28:6
P18:11, P15:7,
P30:4
P30:2, P13:18,
P08:3
P13:17
P08:3
S28:4
S13:1
INDEX OF AUTHORS
Polle, A
Polle, Andrea
Pollmann, Stephan
Polsakiewicz, Monika
Polster, Alexander
Popko, Jennifer
Popp, Alexander
Poppendieck, Hans-Helmut
Pörs, Yvonne
Pouraiiouby, Rana
Pratje, Elke
Preuß, Anja
Preuten, Tobias
Prinsen, Els
Pröschold, Thomas
Puchta, Holger
Pufe, Heidrun
Puigdefábregas, Juan
Pusunc, Susan
Pysek, Petr
S44:3
S01:5
P15:4, P19:10,
P19:17
P05:1, P17:34
P04:7
P15:11
S48:4
L:1
P26:4
P04:17
P17:19
P31:6
P17:12, S10:1
S37:1
P07:5
P33:5
P17:27
S48:2
P04:20
S08:4
Q
Qiu, Xiao
Quandt, Dietmar
Qudeimat, Enas Abdullah
S07:2
P23:11, S44:4,
P23:6
S09:3
R
Radchuk, Ruslana
Radchuk, Volodymyr
Rainer, Hoefgen
Rakitin, Viktor Yurievich
Rakotondrainibe, France
Ralf, Reski
Ramírez, Carlos
Ranf, Stefanie
Ranjeva, Raoul
Rascher, Uwe
Rasouly, Aviram
Rath, Magnus
Ratke, Janina
Ratzinger, Astrid
Rauch, Sabine
Rauh, Daniel
Rauhut, Thomas
Rautenberger, Ralf
Rauwolf, Uwe
Rehn, Frank
Reichelt, Michael
Reinbothe, Christiane
Reinders, Joerg
Reinders, Jörg
Reinhardt, Susanne
Reißer, Werner
Renate, Scheibe
Rennenberg, Heinz
Renner, Susanne S.
Rensing, Stefan
Reschke, Stefan
Reski, Ralf
P15:8
S31:6
S23:4
P33:3
S12:4
S24:5
S21:4
P13:21
S47:3
P18:3
S06:3
P26:9
P14:12
S35:4, P19:18
P20:4
P31:5
P31:30
P06:4
S19:6
P22:21
P15:1
P17:1
P30:9
P32:7
P22:21
P06:12
P32:21
S23:7
S38:1
S44:2
P17:27
S09:3, S47:2,
S44:2, P08:8,
P19:15, L:13
Reuff, Muriel
Rex, Martina
Rexhepi, Jashar
Reyes-Prieto, Adrian
Riaño-Pachón, Diego Mauricio
Ribbeck-Busch, Kathrin
Richardt, Sandra
Richter, Christine
Richter, Dagmar-Ulrike
Richter, Hanna
Richter, Markus
Richter, Peter
Richter, Ute
Richter, Uwe
Riemenschneider, Anja
Rienmüller, Florian
Rigas, Stamatis
Rigaud, Jean-Louis
Rips, Stephan
Ristow, Michael
Ritte, G.
Ritte, Gerhard
Ritter, Claudia
Ritz, Christiane M.
Rödiger, Anja
Roelfsema, M.Rob G.
Roelfsema, Max Robert
Roelfsema, MRM
Roelfsema, Rob
Rohde, Britta
Rohrbeck, Diana
Rohsius, C.
Rohwer, Jens G.
Rohwer, Jens Gunter
Roitsch, Thomas
Roleda, Michael Y.
Roloff, Nils
Romoleroux, Katya
Ron, Eliora
Roos, Werner
Röse, Ursula S.R.
Rosen, Ran
Rosenkranz, H.
Röser, Martin
Rossignol, Michel
Roth, Dietrich
Rothenstein, Dirk
Roth-Nebelsick, Anita
Rottloff, Sandy
Rowe, Nick
Ruan, Jianyun
Ruch, Sandra
Rückert, Christian
Rüdinger, Mareike
Rudolph, Barbara
Rueter, Sebastian
Ruf, Stephanie
Rumbou, Artemis
Rust, Steffen
P13:8
S12:2, P28:10
P11:2
S33:2
S44:5
P08:10
S44:2
P17:4
P31:15
P31:12
P03:12
S16:3
P31:10
S10:1
P15:5
P13:20
P13:32
S25:5
P20:6
S08:3
P18:16
S46:2
P26:1
P23:7, S19:2,
P01:9
P17:9
P32:5
P32:12
P13:29
S06:5, P32:2
P31:8
P31:35
P35:1
P28:19, S12:3,
P28:15
P23:8, P28:3,
P23:5
P04:11, P22:15,
P32:4, P32:9
P06:18
P30:11
S38:5
S06:3
S09:5, P31:20,
P32:16, P32:11,
P32:17
P25:4
S06:3
P14:8
S38:2, P23:10,
P23:3, P23:1
S35:5
S45:3
S28:1
S17:2
P25:5
S17:3
S18:2
P31:9
P15:7
P17:34
P21:2, P23:8,
P28:19, P28:17,
S12:3, P28:14,
P28:15, P28:3
S34:1
P17:25
S42:3
P03:7
INDEX 125
INDEX OF AUTHORS
Ruth, Wolfgang
Rutten, Twan
P31:15
S31:6
S
Saadaoui, Dhouha
Saadatmand, Sarah
Saalbach, Isolde
Saare-Surminski, Katja
Safriel, Uriel Nahum
Sagasser, Martin
Saglam, Aykut
Sahbaz, Rasim
Saigo, Mariana
Saleh, Livia
Salisch, Mario
Salomon, Siegfried
Salonvaara, Sadette
Sánchez, Pedro A.
Sánchez, Ramón Ovidio
Sander, Tim
Sandorf, Iris
Santos, Patricia
Sarker, Rakha
Saruhan, Neslihan
Sattelmacher, Burkhard
Sauer, Michael
Sauer, Norbert
Sauer, Wilhelm
Säumel, Ina
Sauter, Margret
Savage, Natasha Saint
Scalone, Romain
Schaefer, Wilhelm
Schäffer, Wilhelm
Schaller, Hubert
Scharnhop, Helge
Scharr, Hanno
Scharte, Judith
Schattat, Martin Hartmut
Schauer, Nicolas
Scheel, Dierk
Scheibe, Renate
Scheible, Wolf
Schenck, Daniel
Schenk, Manfred K.
Schenk, Tobias
Scherer, Günther
Scheres, Ben
Scherzinger, Daniel
Schiemann, Joachim
Schinke, Anna-Lena
Schinner, Katrin
Schirarend, Carsten
Schlaich, Nikolaus L.
Schlatermund, Nanette
Schlebusch, Maximilian
Schlee, Matthias
Schlicht, Markus
Schlichting, Andre
Schliemann, Willibald
Schlink, Katja
Schlittenhardt, Peter
Schlunk, Ines
126 INDEX
S01:3
P14:4
P08:9
P35:3, P35:4
S48:1
P31:6
P29:3
P35:8
S46:3
P13:18, P08:3
P06:12
P08:11
P29:4
S14:1
P10:1
P13:30
P15:4
S35:4
S18:5
P29:3
P15:3, S18:2
S06:1
P13:2
S19:4
S08:5
S47:5, S09:2,
P15:10
P04:18
S08:6
S22:2
P08:11
P31:40
P31:29
P18:3
P18:15, P18:21,
P18:27
P17:16
P18:32
P13:21
S27:4, S36:5,
P30:3, P30:13
L:11
P32:3
P20:8
P08:5
S16:4
L:9
P31:9
P27:3, P08:7
P17:31
P15:3
P28:19
S22:7, P04:17
S42:1, P27:1
P15:2
S19:4
S16:2
P31:15
S35:7
P22:5
P01:9
P26:3
Schmelzer, Elmon
Schmid, Volkmar H.R.
Schmidt, Hendrik
Schmidt, Kerstin
Schmidt, Lilian
Schmidt, Sabrina
Schmidt, Sabrina Alexandra
Schmidt, Simone
Schmidt, Wolfgang
Schmidtke, Jörg
Schmitt, Anna
Schmitt, Bianca
Schmitt, Christine
Schmitt, U.
Schmitt-Kopplin, Philippe
Schmitz, Boris
Schmitz, Ulf
Schmitz-Streit, Ruth
Schmitz-Thom, Ina
Schmoock, Silvia
Schmülling, Thomas
Schneider, Anja
Schneider, Bernd
Schneider, Harald
Schneider, Julia
Schneider, Katharina
Schnitzer, Daniel
Schnitzler, Jörg-Peter
Schoening, Jan C.
Scholten, Stefan
Schön, Hardy
Schönknecht, Gerald
Schornack, Sebastian
Schreiber, Ullrich
Schreiner, Monika
Schrey, Silvia
Schrey, Silvia Diana
Schriek, Sarah
Schroda, Michael
Schröder, Joachim
Schröder, Peter
Schroeder, Hilke
Schroeder, Indra
Schroeder-Lang, Saskia
Schröter, Yvonne
Schuenemann, Danja
Schuller, Astrid
Schulte, Katharina
Schültke, Stefanie
Schultz, Jörg
Schultz, Matthias
Schulz, Karina
Schulz, Stefan
Schulze, E.-Detlef
Schulze, Jana
Schulz-Raffelt, Miriam
Schumacher, Barbara
Schumacher, Benjamin
Schumacher, Karin
Schumann, Brigitte
Schumann, Rhena
P04:17
S20:3
P30:2
S15:4, P08:7
P25:4
P23:8
P28:14
P19:4
P04:18, S09:6
S15:4, P08:7
P13:12
P13:2
S41:3
P03:8
S35:3
P17:14
S08:3
P22:4
P18:21, P18:27
P22:11
S47:1, P19:5
P13:14
S05:2
S17:5, S17:4,
S12:4, S12:2,
P28:16
P23:10, P23:3,
P23:1
P13:26
P13:28, P13:30
P18:7
P04:13
S02:3, P04:9
P18:15, P18:21,
P18:27
P13:7
P17:16
P22:15
S01:2
P26:10
S35:6
P15:7
S40:4, S10:6
S05:2
S35:3, P17:26,
P29:5
S11:5
S25:3
P32:10
S46:1, P30:8,
P30:7
P17:18
P22:19
S12:6, P28:10
S09:4
P23:12
?:11
P13:6
S30:2
S30:4
P14:6
S40:4
P17:19
P13:23
P13:5, S25:4
S09:5, P31:20
P06:8, S13:4,
P06:6, P06:11,
P07:3
INDEX OF AUTHORS
Schünemann, Danja
Schurr, Ulrich
Schuster, Joachim
Schuster, Martin
Schütz, Nicole
Schwartze, Wieland
Schwarz, Christian
Schween, Ulrike
Schweer, Jennifer
Schweizer, Günther
Schwenkert, Serena
Seebald, Eileen
Seibel, Philipp
Seibert, Sven
Seidel, Claudia
Seidel, Thorsten
Seitz, Stefanie
Selbach, Kristina
Selchow, Olaf
Selig, Christian
Sell, Simone
Selmar, Dirk
Selzer, Philipp
Senbeta W., Fayera
Senger, Toralf
Seumel, Gotelinde
Seumel, Gotelinde Irmgard
Shahollari, Bationa
Shaikhali, Jehad
Shaltout, Kamal H.
Sharifnia, Fariba
Shaw, Blanka
Shishova, Marie
Siegmund, D.
Siemens, Johannes
Sikorski, Martha
Simola, Liisa K
Simon, Andreas
Simon, Rüdiger
Simon, Uwe K.
Simon-Plas, Françoise
Sipman, Harrie J M
Sippl, Wolfgang
Sirrenberg, Anke
Smith, Alan R.
Smith, William K.
Sobczak, Miroslaw
Soljic, Lucija
Soll, Jürgen
Soltani, Asieh
Soltany, Saed
Somerville, Shauna
Sommer, Jan Henning
Sommer, Nicole
Specht, Andre
Speck, Thomas
Sperling, Petra
Spring, Otmar
Sprunck, Stefanie
Sramkova, Anna
Sreenivasulu, Nese
Srilunchang, Kanok-orn
Stackebrandt, Erko
Stadler, Ruth
Staiger, Dorothee
Stammler, Angelika
Stange, Annette
S10:5, P17:2,
P17:4, P17:29
P25:4, P18:3
P15:1
S16:3
P28:18
S09:5, P32:11
P17:24
P23:4
P04:10, P04:15
P22:14
S20:5, P17:10
P23:4
P23:12
P18:29, P18:9
S37:2
P13:28, P13:30
S40:5
P17:35
S28:1
P23:12
S39:1
?:0
P22:10
S41:3
S07:2
S09:3, S24:5
P19:15
P26:1,R:2
P30:1, S36:3
S21:5
P35:7, P35:2
P23:6
S16:4
S28:4
P22:21, P19:19
P17:18, P17:29
P29:4
P07:1
S24:2
P22:22
S36:1
lysasy:7
P31:20
S35:4
S12:2
P03:11
P22:20
S31:1
S27:5
P35:2
P14:4
S22:6
S41:2
P04:14
S36:6
S17:3
P22:13
P22:7, P22:10
S31:1
S12:5
S31:6
S31:1
P28:8
S31:5, P18:1,
P13:2
P04:13
P04:24
P32:2
Stefan, Porembski
Stefenon, Valdir Marcos
Steffens, Bianka
Steger, Gisela
Stehfest, Katja
Steinberg, Karl-Hermann
Steiner, Sebastian
Steinki-Schwarz, Christiane
Steinmacher, Douglas A
Stelljes, Christian
Stengel, Anna
Stenzel, Irene
Steup, Martin
Stieber, Regina
Stierhof, York
Stitt, Mark
Stocker-Wörgötter, Elfriede
Stockmeyer, Kerstin
Stohn, Patrizia
Stöhr, Christine
Stökl, Johannes
Stoll, L.
Stolpe, Thorsten
Stolter, Caroline
Stoppel, Rhea
Stotz, Henrik U.
ST-PIERRE, Benoit
Strack, Dieter
Stracke, Ralf
Strand, Åsa
Strauch, Sebastian
Streit, Wolfgang
Streitner, Corinna
Stremlau, Stefanie
Strickert, Marc
Strnad, Miroslav
Strodtkötter, Inga
Ströher, Elke
Stubbs, Milton
Suer, Stefanie
Sukatar, Atakan
Sundberg, Björn
Sunderhaus, Stephanie
Sur, Ilknur
Svatoš, Aleš
Swai, Ignas
Swai, Ignas S.
Swart, Elsabe
Swiatecka-Hagenbruch, Monika
Symmank, Lars
Szabó, Milán
Szakasits, Dagmar
Szellas, Tanjef
Szewczyk, Marlen
S41:4
P33:4
S09:2
S06:2
P06:1
P02:1
S46:1, P30:8,
P30:7
S23:7
P35:4
P14:12
S27:5
S31:3, P04:8
S46:2
P25:5
P13:5
L:11
S43:1
P22:4
P17:19
S39:2
S12:5, S30:1
P35:1
S06:4
P25:6
P17:10
P22:3
S05:1
P26:2, P31:32,
P31:4, P31:21,
P31:28
P31:6
P18:12
S16:3
P22:4
P04:13
S39:2
P04:12
P19:8
P30:13
S27:3, S27:1,
S36:3
P31:5
P33:5
P31:25
L:14
S04:4
P35:8
S05:2
P01:1
P01:2
S41:5
P17:38
P23:6
P18:10
P22:20, S22:3,
P22:12
P13:4
P31:15
T
Takenaka, Mizuki
Tala, Fadia
Tanaka, G. K.
Tantau, Hanny
Tanwir, Fariha
S04:1, P17:36
P06:13
P03:1
P22:8
S28:1
INDEX 127
INDEX OF AUTHORS
Tarca, A. Laurentiu
Tarkka, Mika
Tarkka, Mika Tapio
Tayefeh, Sascha
Teeri, Teemu H
Ternes, Philipp
Terzi, Rabiye
Teschner, Julia
Tesfaye G., Kassahun
Teuber, Michael
Theißen, Günter
Thell, Arne
Thevissen, Karin
Thiede, Joachim
Thiel, Gerhard
Thiel, Johannes
Thiemann, Alexander
Thierbach, Karsten
Thines, Eckhard
Thomas, Steffi
Thuruthiyil, Dennis Thomas
Thuss, Sabine
Timm, Marie
Timm, Stefan
Timmers, Ton
Timofeeva, G.
Timofeeva, Galina Vladimirovna
Tjaden, Joachim
Tkach, Natalia
Toledo, Pedro
Tolentino, Vivian Salvador
Torgersen, Helge
Törjek, Otto
Tribsch, Andreas
Tritsch, Denis
Trtílek, Martin
Tscheschner, Heike
Tsunoda, Satoshi P.
Twele, Robert
Tyra, Heather
P03:6
P26:10
S35:6
P13:31
P29:4
P22:13
P29:3
S47:4, P17:35
S41:3
P31:10
S24:4, S19:2,
P04:7
P12:3
P22:13
P28:14
S28:3, P13:31,
P13:19
P04:12
P27:2
P30:2
S22:1
P18:20
P33:2
S04:3
P28:19
P18:19
S35:5
P19:1
P33:3
P13:22
S38:2
P06:13
P35:5
S29:1
S04:3
P28:11
P31:40
P18:29
P22:7
S14:1
S12:5
P17:33
U
Uehlein, Norbert
Ullmann, Jörg
Ullmann, Katharina
Ulm, Roman
Umate, Pavan
Usadel, Björn
S14:4
P02:1
S40:3
P32:1
S20:5
L:11
V
Vâlcu, Cristina-Maria
Valdez, Nayuf
Valdivia, Nelson
van Alen, Helge
van Amerongen, Herbert
van Beusekom, Justus
Van de Peer, Yves
van der Linde, Karina
van der Merwe, Johannes A.
van Dongen, Walter
Van Elst, Daan
128 INDEX
P22:5
P22:8
P03:2
P28:7
P18:28
P13:1
S44:1
S36:5
S04:1, P17:36
S31:2
S37:1
Van Etten, James L.
Van Oevelen, Sandra
Vandermeeren, Caroline
Veith, Thomas
Veljovic Jovanovic, Sonja
Verbitskiy, Daniil
Verboom, G. Anthony
Verchot-Lubicz, Jeanmarie
Vernié, Tatiana
Vesa, Simona-Maria
Veste, M
Veste, Maik
Vicente-Agullo, Francisco
Viehweger, Kathrin
Viehweger, Katrin
Virchow, Detlef
Vlasova, Tatiana
Vogel, Mathias
Vogel, Stephanie
Vogt, Thomas
Voigt, Christian Axel
Volke, Daniela
Volkmann, Dieter
Volkov, Roman A.
Volz, Beate
von Bargen, Susanne
von der Fecht-Bartenbach, Jenny
von Hagen, K. Bernhard
von Lyncker, Ludwig
von Rad, Uta
von Schaewen, Antje
von Schwartzenberg, Klaus
von Thülen, Amke
Voss, Ingo
Voß, Karsten
Voytsekh, Olga
Vugrinec, Sascha
S28:3
S37:1
S25:5
P14:3
P29:1
S04:1, P17:36
P23:13
P13:7
S35:5
S36:1
P03:8
P10:2, P10:1
P13:32
S09:5
P32:13
P01:1
P12:1
P31:20
P22:8
P31:5, P31:38,
P31:28
S22:6
P18:10
P09:1, S16:2
P28:13
P14:11
S42:3
P13:5
S38:2
S31:4
P26:10
P18:15, P20:6,
P17:20
P31:12, P19:8
P31:7
P30:3
P35:6
S40:5
P18:23, P13:27,
P17:23
W
Waadt, Rainer
Wägele, Johann-Wolfgang
Wagenitz, Gerhard
Wagner, Carola
Wagner, Heiko
Wagner, Natascha
Wagner, Raik
Wagner, Richard
Wagner, Volker
Wahl, Markus
Wahl, Martin
Wahrmund, Ute
Walter, Agnes
Walter, Michael H.
Waltermann, Angelika
Walther, Gian-Reto
Walz, Alexander
Wan, Yinglang
Wang, linzhu
Wanke, Dierk
Wanke, Stefan
Warinowski, Tino
S09:4
P28:8
S45:2
P22:14
P06:1
P28:18
S46:1, P18:25
S14:2
S40:3
P13:22
S13:3
P05:1
S47:3
P26:2, P31:32,
P31:4
S42:4
S08:1
S37:2
P09:1, S16:2
S11:3
P20:11, P20:2,
P20:10
P23:9
P29:4
INDEX OF AUTHORS
Warnecke, Dirk
Weber, Andreas
Weber, Andreas Paul Michael
Weber, Andreas PM
Weber, Hans
Weber, Hans Christian
Weber, Till
Weckermann, Katrin
Wege, C.
Wege, Stefanie
Wegner, Lars
Wehner, Peter
Weier, Diana
Weigelt, Kathleen
Weihe, Andreas
Weinberger, Florian
Weis, Engelbert
Weishaar, Bernd
Weising, Kurt
Weisser, Wolfgang W.
Weitzel, Corinna
Welsch, Ralf
Wen, Jun
Wenclawiak, Bernd W.
Wenk, Meike
Wenkel, Stephan
Werner, Dagmar
Werner, Sonja
Werner, Tomáš
Werr, Wolfgang
Weschke, Winfriede
Westhoff, Markus
Wicke, Susann
Wieczorek, Krzysztof
Wienand, Udo
Wiencke, Christian
Wildhagen, Henning
Wilhelm, Christian
Wilhelm, Ralf
Willeke, Claudia
Willemsen, Viola
William, Meva Meva
Willmund, Felix
Wiltshire, Karen Helen
Winterfeld, Grit
Wirsel, Stefan
Wirtz, Markus
Wissemann, Volker
Wobbe, Lutz
Wobbe, Tobias
Wobus, Ulrich
Wodniok, Sabina
Wojtera, Joanna
Woldemariam G., Tadesse
Wolf, Carolin
Wolf, Matthias
Wölfel, Jana
Wolfgang, Erker
Wolfram, Karina
Wollschläger, Jochen Felix
Worberg, Andreas
P22:13, S39:5
P13:24
P13:15, S46:4,
P18:4
S14:3, P17:33
P15:8, P08:9
P26:11, P26:9,
P31:1
S27:2
P20:9, P18:2
S28:4
P04:23, P04:24
S34:7
P26:1
P04:12
P08:9
P17:25, S10:1
S13:3
P18:15, P18:21,
P18:27
P31:6
S12:2, S19:7,
P28:10, P28:18
S30:4
P31:14
P31:39
P31:1
S06:2
P04:19
S24:3
S31:5, P18:1
S33:3, P14:3
S47:1, P19:5
S02:2
P04:12
S34:7
S44:4
S22:3, P22:12
S10:3, P04:21,
P04:20, P04:22,
P08:2
P06:11, P06:18,
P03:2
S23:7
P06:1, S33:3,
P18:10
P08:7
S47:2
L:9
P31:22
S10:6
P13:1, P14:1
P23:3
S22:1
S23:2
S19:2
S20:2
P22:13
S31:6, P04:12
P07:1
S36:5, P32:21
S41:3
P32:17
P23:12
P06:11
P18:17
S35:7
P35:3
P23:11
Wowk, Myroslawa
Wu, Guahoi
Wu, Weicheng
Wu, Wenying
Wuennenberg, Petra
Wulff, Angela
Wunrau, Christina
Wurz, Rebecca
P23:2
S07:2
S48:3
P31:1
P13:21
P06:18
S36:5
P33:5
Y
Yang, Mingjie
Yang, Thomas
Yang, Thomas Ju Wei
Yatusevich, R.
Ye, Wanzhi
Yellina, Aravinda lakshmi
Yilmaz Koz, Ferda Fethiye
Yin, Chang
Yoon, Insun
P13:3
P04:18
S09:6
P31:3
P22:2
P04:23
P31:25, P31:16
S10:1
P04:3
Z
Zacher, Katharina
Zachgo, Sabine
Zafar, Yusuf
Zahn, Marc
Zähringer, Ulrich
Zakharova, E. V.
Zakharova, Ekaterina Vladimirovna
Zanetti, Eugenia
Zank, Thorsten
Zäpernick, Marion
Zäuner, Simone
Zauner, Stefan
Zdanowska, Magdalena
Zehrmann, Anja
Zetzsche, Holger
Zhang, Lizhi
Zhu, Zhujun
Ziegler, Jörg
Ziegler, Paul
Zimmer, Andreas
Zimmer, Martin
Zimmermann, Dirk
Zimmermann, Ulrich
Zinchenko, Vladislav
Zippel, Karin
Zipper, Reinhard
Zirr, Kerstin
Zizka, Georg
Zoglauer, Kurt
Zörb, Christian
Zoschke, Reimo
Zschiesche, Wiebke
Zufall-Roth, Elke
Zunke, Ulrich
Zvjaghina, Natalia
P06:18
S03:3, S24:1
S18:6
S16:4
P22:13
P19:1
P33:3
P20:1
S07:2
P03:12
P22:13
S33:3
S37:1
S04:1, P17:36
P28:8
S15:3
P15:3
P31:2
P15:12
S44:2
S13:3
S34:7
S34:7
P15:2
S18:4
P22:7
P31:26
S12:6, P28:10,
P28:18
P03:12
P15:9, P22:18
P17:12
P04:14
S33:6
S11:6
P11:1
INDEX 129
NOTES
130 NOTES
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