Abstract
In Arabidopsis, the induction of a dehydration-responsive gene, RD22, is mediated by ABA. Previous experiments have established that MYC- and MYB-recognition sites in RD22 promoter function as cis-acting elements in the dehydration-induced gene expression. A MYC-related factor (RD22BP1) and a MYB-related factor (ATMYB2) have been isolated. We have shown that transgenic plants overexpressing RD22BP1 and/or ATMYB2 cDNA displayed ABA hyper sensitivity. ABA induced gene expression of the RD22 gene also showed the ABA hypersensitivity. Moreover, Ds-insertion mutant of the RD22BP1 (rd22bp1) gene showed ABA less-sensitivity. In rd22bp1 mutants, ABA induced gene expression of the RD22 gene was significantly decreased. In this meeting, we will show the isolation of the RD22BP1 interacting factors and discuss about the function of these factors in ABA signaling.
