Gene Expression during Water Stress

Abstract

The severity of the water loss, the developmental stage and the physiological condition determine the response of plants to water stress of affected plants. We initiated research with the objective to identify gene products which may contribute to water stress tolerance using a resurrection plant and barley embryos as model systems. The unique ability of resurrection plants to withstand severe water loss greater than 90% makes them a suitable system to study water stress tolerance: upon rewatering these plants recover quickly from the stress (Gaff 1971, Bartels et al. 1990). An attractive feature of the resurrection plant Craterostigma plantagineum is that we can analyse desiccation tolerance in undifferentiated callus tissue, too. Callus withstands rapid dehydration if it is treated with the plant hormone abscisic acid (ABA) prior to the drying treatment (Bartels et al. 1990). This makes two experimental systems available from the same plant for the isolation of molecular components relevant to desiccation. Initially we isolated a large number of cDNA clones which are induced upon dehydration and/or ABA treatment (Bartels et al. 1990, Piatkowski et al. 1990, Bartels et al. 1992).