The work outlined in this proposal will identify how processes at a range of different organizational levels (from genes to cellular events) contribute to salt tolerance of plants and whether their manipulation in transgenic plants can improve salinity tolerance. The project will use a number of different approaches to investigate the mechanisms and pathways that contribute to the tolerance of specific ion stresses when plants are grown in saline conditions, particularly processes involved in the regulation of cellular ionic composition. The hypothesis underlying the proposal is that regulation of cellular, particularly cytosolic, ion concentrations is central to salt tolerance and that this is regulation is achieved by modification of ion transport at the plasma membrane through changes in both the complement of transporters (gene expression) and their activity (biochemical regulation). The role of signal transduction and other regulatory pathways
(phosphorylation/dephosphorylation) is a major focus both because our knowledge of how transport is regulated is rudimentary and because some Na'-sensitive enzymes may modulate inositol-based signalling pathways.
The specific objectives are:
1. To understand the regulation of cytosolic and vacuolar ion concentrations in plants exposed to salinity, and to identify and characterise the membrane transport processes involved
2. To determine the effect of salinity on the regulation of ion transport, including changes in gene expression, biochemical modification of transporters, and regulation by small molecules or proteins
3. To study and elucidate the role of signal transduction pathways in salinity responses in plants, with particular emphasis on pathways already shown to be important in salinity responses of the yeast
4. To identify additional genes with a role in salt tolerance The information gained is expected to provide strong indications of the key processes that need to be manipulated to improve the salinity tolerance of plants and some of the genes produced should be useful both in marker-assisted breeding and direct genetic manipulation of crops for improve salt tolerance.
Funding SchemeCSC - Cost-sharing contracts
221 00 Lund