Book of Abstracts - Geyseco

FESPB 2010 - XVII Congress of the Federation of European Societies of Plant Biology
P07-055: ANALYSIS OF ABIOTIC STRESS RESPONSES
USING PROTEOMIC APPROACHES
Hedtmann, C. 1 - Kaspar, S. 1 - Lippmann, R. 1 - Doell, S. 1 - Matros,
A. 1 - Mock HP 1 - Witzel K 2
1
Leibniz Institute of Plant Genetics and Crop Plant Research
2
Instituts für Pflanzenernährung und Bodenkunde der Universität
Kiel
The presentation will focus on the application of proteomics performed
on model and crop plants to elucidate mechanisms and
traits related to abiotic stress tolerance. Although proteomics still
is limited in comprehensiveness when compared with transcriptomics,
it can provide valuable information not obtained by other
“omics”-techniques. We apply 2-D gel based as well as LC-MSbased
approaches to study the responses of plants towards abiotic
stresses on the protein level. A major focus of recent work relates
to the function of co-chaperones which are induced by various
stresses. These co-chaperones with homology to the human
HOP protein are represented as dimers and within larger protein
complexes and are located both in the cytosol and the nucleus.
Central for our further work is the use of the wide genetic diversity
represented e.g. in the plant genebank of our institute. As
an example, barley was evaluated for contrasting salt tolerance
using mapping populations.
P07-056: ARSENATE SIGNALLING IN ARABIDOPSIS
THALIANA
Leyva Tejada, A. - Castrillo Molina, G. - Pablo Catarecha, Z. -
Eduardo Sánchez, B. - Leo Del Puerto, Y.
Centro Nacional de Biotecnología-CSIC
*Corresponding author e-mail: aleyva@cnb.csic.es
In soils arsenic is primarily in the form of arsenate [As(V)] (Tamaki
and Frankenberger, 1992, Brown et al 1999). Due to its
chemical similarity to phosphate (Pi), As(V) is highly toxic to
plants since it is readily incorporated through the high affinity
phosphate transporter (McNair et al., 1992). This transport system
is induced by Pi starvation and repressed in its presence.
We have demonstrated that the genes induced by Pi are properly
down regulated by As (V) (Catarecha et al 2007). In fact, some
of these genes (Pi transporter PHT1;1 included), are repressed by
As (V) more efficiently than by Pi. Analyzing the transcriptomic
profile of the As(V) response in Arabidopsis thaliana, we have
found that this behavior occur at least in 10 % of the Pi-inducible-genes.
These data indicates that in the case of As(V) and Pi
their signaling mechanisms shares common elements. In order
to identify these and others different elements, we start working
in the characterization of mutants alters in the PHT1;1 repression
by As(V). In this regard, we have analyzed the kinetics of
PHT1;1 repression using a transgenic line expressing the gen of
luciferase drive by PHT1;1 promoter. This tool provide us the
possibility to concluded that this promoter are rapidly repressed
by As(V) and in the case of Pi this repression is retarded (30
min and 36 h respectively). In addition, the screening of an EMS
mutagenized population expressing PHT1;1:LUC led us to the
identification of mutants alters in the repression
by As (V). The mapping of these genes will allow us the characterization
of key elements in the As (V)
perception.
P07-057: MITOCHONDRIAL PROTEASE, ATFTSH4, IS
REQUIRED FOR ARABIDOPSIS GROWTH AND DEVE-
LOPMENT UNDER CONTINUAL MODERATE HEAT
STRESS.
Smakowska, E.* - Kicia, M. - Gibala, M, - Janska, H.
University of Wroclaw
*Corresponding author e-mail: elwira@ibmb.uni.wroc.pl
We found, that a loss of mitochondrial AtFtsH4 protease significantly
affect Arabidopsis growth and development under continual
moderate heat stress (long days at 30oC). The ftsh4 mutant
plants have shorter roots and stems, beside an emergence of true
leaves but not cotyledons is delayed compared with wild-type
plants. The true leaves are smaller and an important characteristic
of the adult leaves is the asymmetric shape and irregular serration
of leaf blades. Moreover, the inflorescence development of the
ftsh4 plants growing at 30oC is arrested and, as a consequence,
ftsh4 plants are unable to produce seeds.
Although the growth and development of the ftsh4 mutants is
highly susceptible to continual moderate heat stress, the mutants
are not defective in acquired thermotolerance based on physiological
experiments. In agreement with this result, the transcript
level of AtHsp 101, which is a cytosolic heat shock protein required
for acclimation to high temperature, is similar in the wild-type
and ftsh4 when plants are exposed to both a short severe heat
stress (1h, 38oC) or continual moderate heat stress (1-4 weeks,
30oC). We also established that the mitochondrial AtFtsH4 protease
is not a typical heat shock protein like Hsp101, because we
haven’t found an increased accumulation of the AtFtsH4 transcripts
upon a short time of high temperature stress. These results
suggest that the thermosensitivity observed in the ftsh4 mutants
is not caused by a defect in induction of cytosolic Hsp101 expression.
P07-058: POLY ADP-RIBOSE POLYMERASE INVOLVE-
MENT IN PROGRAMMED CELL DEATH OF TOBACCO
BY-2 CELLS
Locato, V. 1 - Cimini, S. 2 - Novo Uzal, E. 2 - de Pinto, M.C. 3 - Foyer,
C.H. 4 - De Gara, L. 1
1
CIR-University Campus Bio-Medico di Roma
2
Departamento de Biología Animal, Vegetal y Ecología, Universidad
de A Coruña
3
Dipartimento di Biologia e Patologia vegetale, Università di
Bari
4
Centre of Plant Science, Leeds University, UK
The term “programmed cell death” (PCD) refers to an apoptoticlike
cell death that occurs during plant development and/or as
consequence of various injuries. Plant PCD has many common
features with animal apoptosis, but it also has some unique features
related to the morphological and functional differences between
the plant and animal systems. Like apoptosis, plant PCD
initiation generally requires an accumulation of reactive oxygen
species (ROS). Enhanced ROS production or depletion of antioxidants
leads to oxidative stress, which can cause damage to
cell structure and DNA. Moreover, ROS can act as molecular signals
that regulate the progression of PCD. Animal and plant cells
have defence and repair systems that counteract cell injury and
DNA breakage. Poly-ADP ribosylation is a major process involved
in DNA repair during oxidative stress and apoptosis that has
been intensively studied in animal systems. However, little information
is available on this process in plant cells. Here we report
a study in which tobacco BY-2 cells were subjected oxidative
stress-triggered PCD. Our results showed that poly ADP-ribose
polymerase (PARP) activity was increased rapidly as consequence
of oxidative stress. However, within hours of PCD activation
PARP activity was decreased. PARP uses NAD+ to drive poly-
ADP ribosylation. Thus, we suggest that regulated activation and
deactivation of PARP might avoid energy depletion during PCD
in order to sustain the energy-demanding death process.
P07-059: LOOKING FOR CADMIUM TOLERANT MU-
TANTS
Agorio, A. 1 - Dardennes, J.S. 2 - Thomine, S. 1
1
Institut des Sciences du Végétal (CNRS)
2
Agroparistech
Exposure to cadmium (Cd) has adverse health effects. Human
uptake of Cd occurs mainly through the food-chain and tobacco
smoke, as a consequence of heavy metal accumulation by crop