15th International Conference on Arabidopsis Research - TAIR

T04-111
Abiotic stress signaling and tolerance
Jian-Kang Zhu(1)
1-University of California at Riverside
Detecting and responding to environmental perturbations are important for
all living organisms. Our lab is interested in the molecular mechanisms underlying
plant responses to harsh environments such as soil salinity, drought
and cold temperatures. In addition, we are interested in the mechanisms of
transcriptional gene silencing and in the role of epigenetic gene regulation in
stress adaptation. We use a combination of genetic, biochemical, genomic
and proteomic approaches to analyze various levels of gene regulation (chromatin
level/epigenetic, transcriptional, posttranscriptional, and protein activity)
and to understand stress signaling and stress tolerance. Our long-term
goals are to elucidate the signaling pathways used by plants in responding to
environmental stresses and to identify key genes for modifying the responses
of crops to environmental stresses which ultimately will lead to major contributions
to agriculture and the environment. In this presentation, I will give
an overview of recent progress in the area of abiotic stress responses, and
describe some recent results from my lab on salt, drought and cold stress
signal transduction in Arabidopsis. Potential involvement of microRNAs and
other small regulatory RNAs in abiotic stress responses will be discussed.
T04 Interaction with the Environment 1 (Abiotic)
T04-112
Role of membrane fluidity in cold perception in
Arabidopsis thaliana suspension cells.
VAULTIER Marie-Noëlle(1), ZACHOWSKI Alain(1), RUELLAND Eric(1)
1-Physiologie Cellulaire et Moléculaire des Plantes, CNRS/Université Paris VI
Perception and transduction mechanisms of cold signal begin to be elucidated
in plant cells. Signalisation pathways implying phospholipases are part of
the transduction (Ruelland et al., (2002) Plant Physiol.130: 999-1007). We
wanted to characterize some of their properties in Arabidopsis thaliana suspension
cells. The existence of a temperature threshold for phosphatidic acid
production by phospholipase C and D in response to cold was demonstrated.
Besides, we have shown that this temperature triggering of phospholipase C
and D activation was shifted in systems where membrane fluidity was modified
artificially (pretreating cells with fluidifying or rigidifying agents as benzyl
alcohol or dimethylsulfoxyde, respectively), physiologically (acclimated cells)
or genetically (mutants of desaturation pathways). Results have evidenced
that membrane rigidification plays a central role in signal perception leading
to phospholipase C and D activation when plant cells are exposed to cold
15 th <strong>International</strong> <strong>Conference</strong> on Arabidopsis Research 2004 · Berlin