Abstract
An Arabidopsis thaliana RD26 cDNA isolated from dehydrated plants, encodes a NAC protein. The expression of RD26 gene was induced not only by drought but also by ABA and high salinity. In this report, we identified target genes of RD26 protein by a microarray analysis of the transgenic plants overexpressing RD26. In a transient transactivation experiment using Arabidopsis protoplasts, RD26 protein activated transcription of a reporter gene driven by a promoter of a target gene that identified by using the microarray analysis. Taken together with the finding that RD26 overexpressors exhibited ABA-hypersensitivity, the observation on the reppressed expression of RD26 in aba mutant suggested that RD26 requirs ABA for their activation. Moreover, based on the analysis of loss-of-function mutants, an important role of RD26 in ABA-signal transduction pathway will be discussed
