Many plant genes have been shown to be induced by drought stress and function in drought tolerance. We isolated more than 40 independent genes that are responsive to drought in Arabidopsis thaliana and cowpea and analyzed the structure of their gene products. Sequence analyses of these genes indicate that their gene products may function in protecting cells from dehydration. We also analyzed the expression of these genes under various stress conditions. Some of the drought-responsive genes are induced by plant hormone abscisic acid (ABA), unlike others. There seem to be at least four independent signal transduction pathways between initial drought stress signal and gene expression. Two of the pathways are ABA-dependent and two are ABA-independent. We precisely analyzed the promoter regions of two drought-inducible Arabidopsis genes, rd29A and rd29B, in both transgenic· Arabidopsis and tobacco, and identified a novel cis-acting element containing 9 bp, TACCGACAT (DRE, Dehydration Responsive Element), that is involved in the AHA-independent response of rd29A to conditions of dehydration and high salt. DRE is also involved in the induction by low temperature, but does not function in the AHA-responsive, slow expression of rd29A.