29 Environmental Stress and Gene Regulation

Abstract

The many facets of plant responses to environmental stress may include morphological and ultrastructural changes, alterations in metabolic pathways, and transcriptional regulation of genes. Despite a great deal of research on plant stress, the mechanisms by which plants sense and respond to many environmental changes are largely unknown, particularly at the gene level. In addition, although considerable information concerning the responses of plants to different types of stress has been published in other species, relatively few studies have been conducted with Arabidopsis.

In this chapter, we discuss the processes involved in the environmental signal transduction chain, linking a given environmental stimulus to gene expression and regulation. A multitude of genes, their sequences, and their subsequent protein profiles produced have been reported in numerous types of plants under many environmental stresses. Therefore, discussion of what is known about stresses in other plants precedes discussions concerning Arabidopsis. Many of the genes and proteins described in the literature have been named according to an extraction procedure, or according to the particular stress (e.g., cold, salt, water) they were associated with when described. It is becoming evident that many of these genes and proteins are induced in response to more than one stress, and that those expressed under different stresses are similar in sequence or function. Therefore, the nomenclature of many of the genes presented here is different because of historical context, even if they share an evolutionary base or function.

In this chapter, we review UV light, water, heat, and hypoxia stress in...