Plants respond to drought through physiological and developmental changes. Many genes have been shown to be induced by dehydration stress and function in the tolerance of plants to drought. We isolated 25 independent genes that are responsive to dehydration in Arabidopsis thaliana and analyzed the structure of their gene products. Sequence analyses of these genes indicate that their products may function in protecting cells from dehydration. We also analyzed the expression of these genes under various stress conditions. Some of the dehydration-responsive genes are induced by the plant hormone abscisic acid (ABA), unlike others. There seem to be at least three independent signal transduction pathways between initial dehydration stress signal and gene expression. We precisely analyzed the promoter of two dehydration-inducible Arabidopsis genes, rd29A and rd29B, in transgenic plants, and identified a novel cis-acting element containing 9 bp, TACCGACAT (DRE, Dehydration Responsive Element), that is involved in the ABA-independent response of rd29A to dehydration or high salt conditions. DRE is also involved in the induction by low temperature, but does not function in the ABA-responsive, slow expression of rd29A. One of the myb-related genes, Atmyb2, that is responsive to water stress and abscisic acid (ABA) has been cloned from Arabidopsis thaliana. Atmyb2 encodes a transcription factor and binds to conserved MYB recognition sequence. These results suggest that the ABA-mediated induction of dehydration-inducible genes whose expression requires protein synthesis may be regulated by the ATMYB2 protein.