Hormonal plant cell signalling involves a complex network
specified by a unique intracellular compartmentation
Barbier-Brygoo, H., Lapous, D., Ephritikhine, G.
Institut des Sciences Végétales, CNRS UPR 40, Avenue de la Terrasse,
F-91198 Gif sur Yvette Cedex, France
Unravelling signalling pathways by which plants respond to endogenous regulators controlling their development, or adapt to changes in their environment represents a longstanding goal of plant physiology studies [1]. Although substantial progress has been made in the last years toward the characterization of transduction mechanisms mediating some of these responses and the identification of the involved genes, the description of plant signalling networks is still far from complete. An emerging picture is that the various pathways involve specific receptors, a variety of signalling components with remarkably conserved functions between plants and other eukaryotes, and rely on a tight coordination of several intracellular compartments required to ensure a specific response [2]. Using the model plant Arabidopsis thaliana, we developed a genetic approach aiming at the isolation of mutants altered in hormone-regulated cell elongation. We isolated a dwarf mutant, sax1, which turned out to be altered in its sensitivity to four different hormones (hypersensitive to abscisic acid and auxin for root elongation, resistant to gibberellins and ethylene for hypocotyl elongation) and can be rescued by exogenous application of a fifth hormone, brassinosteroid. This mutant will be described and used as an example to illustrate specific features of hormone signalling in plant cells.
[1] Trewavas and Malho, 1997, Plant Cell, 9:1181
[2] Barbier-Brygoo et al, 1997, Trends Plant Sci, 2:214
| LOCATION |
DATE |
TIME |
| Lecture Hall I |
Monday, April 6 |
03:00 pm |