Abstract
Under abiotic stress conditions such as drought and high salinity, abscisic acid (ABA) levels increase in plants, thereby triggering the expression of many genes that function in the stress tolerance. Many ABA-inducible genes contain a conserved cis-element designated ABRE (ABA-responsive element) in their promoter regions. Arabidopsis cDNAs encoding bZIP-type transcription factors referred as ABRE-binding (AREB) proteins or ABRE-binding factors (ABFs) were isolated using the yeast one-hybrid screening method. Among these transcription factors, expression of AREB1, AREB2, and ABF3 was upregulated by ABA, dehydration, and high-salinity stresses in Arabidopsis plants. Based on results of analyses of areb1 areb2 abf3 triple mutant, here we report that these AREB family transcription factors are involved in the ABA and stress signaling. Moreover, taken together with the information on expression patterns of these proteins, we will discuss the role of each AREB transcription factor.
