Abstract
The plant hormone abscisic acid (ABA) is accumulated under drought and high salinity, and triggers expression of many ABA-responsive genes that appear to enhance tolerance to water stress. A large number of ABA-induced genes have conserved cis-elememts, ABREs (ABA-responsive elements) that control expression of ABA-responsive genes in their promoter regions. Arabidopsis cDNAs encoding the basic-domain leucine zipper (bZIP) transcription factors known as ABRE-binding (AREB) proteins or ABRE-binding factors (ABFs) were isolated. We have revealed that Arabidopsis and rice AREB genes are transcriptional activator of ABRE-dependent ABA signaling involved in water stress tolerance. Here we identified and characterized soybean (Glycine max [L.] Merr) AREB/ABF homologous genes (GmAREB), as soybean is an economically important global crop. Four putative soybean AREB family genes were identified by an alignment analysis and were named GmAREB1, GmAREB2, GmAREB3, and GmAREB4. We cloned them and analyzed by using transient expression assay and transgenic Arabidopsis plants overexpressing GmAREB. We will discuss a role of the GmAREB genes in ABA signaling in response to water stress.
