Book of Abstracts - Geyseco

FESPB 2010 - XVII Congress of the Federation of European Societies of Plant Biology
PS03: SYSTEMS BIOLOGY &
Omics
Session lead lectures
PS03-001: SYSTEMS ANALYSIS OF THE CONTRIBU-
TION OF METABOLISM TO GROWTH IN ARABIDOP-
SIS
Stitt, M.*
Max Planck Institute of Molecular Plant Physiology, Golm, Germany
*Corresponding author, e-mail: stitt@mpimp-golm.mpg.de
Plants are exposed to a continually changing environment, including
the diurnal light-dark cycle, and changes that are superimposed
on this cycle. Starch provides the major carbon store
for growth at night. We have used ‘omics analysis of responses
during the diurnal cycle to investigate how growth is coordinated
with the momentary and longer-term changes in the carbon.
Thousands of transcripts show large diurnal changes of their
levels. These can be predicted using a simple linear model, in
which the clock, sugar and light as the major inputs. Some of
the most striking and best-predicted changes are for genes involved
in protein synthesis. Polysome analyses reveal that the
global translation rate is tightly tied to the momentary carbon
availability. To explore the relation between translation and plant
growth more closely, we have carried out quantitative analyses
of rRNA, transcripts, polysome loading and protein abundance.
This allows us to model the relationship between basic molecular
parameters like ribosome and transcript concentrations and
the whole plant carbon budget and growth. The results show that
protein synthesis represents a significant component of the total
plant energy budget, and is regulated to optimise energy costs
on a diurnal basis, and probably also during long term adaptations
to environmental conditions. These results receive independent
support from a complementary approach, in which we
have identified integrative molecular and metabolic parameters
that determine biomass production in a panel of 100 Arabidopsis
accessions. These reveal that starch and protein are correlated
with each other, act as integrators of the metabolic response, and
are negatively correlated with rosette biomass, and also reveal a
strong impact of ribosome abundance and the efficiency of ribosome
use on biomass formation.
PS03-002: CONSTRAINT BASED MODELLING – A NEW
APPROACH TO SYSTEMS-LEVEL STUDY OF PLANT
METABOLIC NETWORK
Zhu, X.*
CAS-MPG Partner Institute for Computational Biology
*Corresponding author, e-mail: zhuxinguang@picb.ac.cn
Identifying new ways to improve photosynthesis is one feasible
approach to increase crop potential yields. Building dynamic
systems models of photosynthesis and plant primary metabolism
is one option to identify targets to increase photosynthesis. This
method however is often limited by the shortage of kinetic parameters,
which demands development of high throughput methods
to characterize the compartment-specific information about
the metabolomics, proteomics and enzyme activities related to
photosynthesis and plant primary metabolism. Constraint based
modelling on the contrary requires less detailed kinetic information.
It has been used widely in microbiology community to
study metabolism and regulation at a genomic scale. A few constraint
based models have been developed in the last five years to
study plant metabolic network properties. In this lecture, I will
briefly discuss the concept, methodology, major applications and
challenges of using this approach in plant biology research. The
potential of linking this method to high throughput data to sudy
the response of plants to climate change and identifying new options
to increase photosynthesis will be discussed.
PS04: REPRODUCTIVE DEVE-
LOPMENT
Session lead lectures
PS04-001: SELF-INCOMPATIBILITY SIGNALLING NET-
WORKS: CONVERSATIONS THAT TELL “SELF” PO-
LLEN TO COMMIT SUICIDE
Wheeler, M.J. - de Graaf, B.H.J. - Wu, J. - Poulter N.S. - Wilkins,
K.A. - Vatovec, S. - Franklin-Tong, V.*
University of Birmingham
*Corresponding author, e-mail: v.e.franklin-tong@bham.ac.uk
Self-incompatibility (SI) is controlled by a multi-allelic S locus
that allows discrimination between “self” pollen from “non-self”
pollen. In Papaver rhoeas, the pistil S determinant (recently renamed
as PrsS, Papaver rhoeas stigma S) encodes a small novel
protein that interacts with incompatible pollen, triggering a Ca 2+ -
dependent signalling network. We recently identified the Papaver
pollen S-determinant (Papaver rhoeas pollen S), PrpS, which
encodes a novel ~20 kDa transmembrane protein with no homology
to sequences in existing databases. I will present our data
showing that PrpS has the attributes expected of a pollen S locus
determinant, including functional data5. I will also present recent
data suggesting that PrsS acts as a ligand, stimulating non-specific
cation conductance permeable to Ca 2+ and K + . Downstream of
interaction of PrsS with PrpS, we have identified several events
that are triggered specifically in an incompatible situation. These
include rapid alterations to the actin cytoskeleton 1,2 and programmed
cell death, involving caspase-like activities 3,4. I will present
unpublished data identifying further SI-specific events triggered
in incompatible pollen. We have recently begun studies of PrpS
in Arabidopsis and I will present preliminary data showing that
poppy SI appears to function in Arabidopsis.
References
1. Snowman BN, et al. (2002) Plant Cell 14, 2613-2626.
2. Poulter NS, et al (2010) Plant Physiol 10.1104/pp.109.152066
3. Bosch, M. & Franklin-Tong, V. E. (2007) PNAS 104, 18327-
18332.
4. Thomas, S. G. & Franklin-Tong, V. E. (2006) Nature 429, 305-
309.
5. Wheeler, M. J. et al. (2009) Nature 459, 992-995.
PS04-002: CELL-CELL COMMUNICATION DURING
FERTILIZATION IN ARABIDOPSIS: A SURPRISING
LINK TO DISEASE RESISTANCE
Kessler, S. 1 - Escobar-Restrepo, J. M. 1 - Huck, N. 1 - Asano, H. 1 -
Kienath, N. F. 2 - Panstruga, R. 2 - Grossniklaus, U. 1 *
1Institute of Plant Biology & Zürich-Basel Plant Science Center,
University of Zürich
2Max-Planck Institute for Plant Breeding Research, Cologne
*Corresponding author, e-mail: grossnik@botinst.uzh.ch
Research in our laboratory focuses on the developmental genetics
of plant reproduction. Our studies have shown that both
genetic and epigenetic mechanisms play a key role in plant reproduction.
We have isolated a female gametophytic mutant,
feronia, which disrupts double fertilization: in feronia mutant
embryo sacs the pollen tubes, even if wild-type, are unable to
release the sperm cells to effect fertilization (Huck et al., 2003,
Development 130: 2149). This phenotype suggests that the female
gametophyte plays a crucial role in pollen tube reception and,
thus, controls the behaviour of the male gametophyte. The feronia
mutant defines novel signalling processes between the male
and female gametophytes in the process of double fertilization
FERONIA was shown to encode a receptor-like kinase of a plantspecific
subfamily (Escobar-Restrepo et al., 2007, Science 317:
656). Interestingly, some interspecific crosses result in phenotypes
that are very similar to those observed in the feronia mutant.
I will report on the molecular and biochemical characterization