Analysis of downstream genes of DREB2A, a transcription factor involved in dehydration and salt-stress response, using transgenic Arabidopsis plants overexpressing a constitutive active form of DREB2A

Abstract

DREB2A is a transcriptional factor that functions in drought and high-salinity responsive gene expression. This protein specifically binds to DRE/CRT in the promoter region of stress-inducible genes and seems to require post-translational modification for its activation. DREB2A has a negative regulatory domain in the central region, and deletion of this region makes DREB2A a constitutive active form (DREB2A CA). We generated transgenic Arabidopsis plants overexpressing 35S:DREB2A CA. The microarray analysis of the transgenic plants revealed that many water-stress inducible genes were expressed in the transgenic plants even under non-stressed condition. Induction of heat-shock related genes was also detected by overexpression of DREB2A CA. We have analyzed expression profile of DREB2A under heat-shock condition. The expression of DREB2A was rapidly and transiently induced by heat-shock treatment. This result suggests that DREB2A may be involved in not only drought and high-salinity response but also heat-shock response.