Molecular Responses to Water Deficit

Abstract

Water deficit elicits a complex of responses beginning with stress perception, which initiates a signal transduction pathway(s) and is manifested in changes at the cellular, physiological, and developmental levels. The set of responses observed depends upon severity and duration of the stress, plant genotype, developmental stage, and environmental factors providing the stress. Cellular water deficit may result from stresses such as drought, salt, and low temperature. This complexity makes it difficult to uncover the responses to water deficit that enhance stress tolerance. In recent years efforts have tumed toward isolation of genes that are induced during water deficit in order to study the function of droughtinduced gene products and the pathways that lead to gene induction. Changes in gene expression are fundamental to the responses that occur during water deficit, and they control many of the short-and long-tem responses.