In @entity958 , the induction of a dehydration-responsive gene, @entity22714 , is mediated by @entity2271 ( @entity2272 ) and requires protein biosynthesis for ABA-dependent gene expression. Previous experiments established that a 67-bp DNA fragment of the @entity22714 promoter is sufficient for dehydration- and ABA-induced gene expression and that this DNA fragment contains two closely located putative recognition sites for the basic helix-loop-helix protein MYC and one putative recognition site for MYB. We have carefully analyzed the 67-bp region of the @entity22714 promoter in transgenic @entity286 plants and found that both the first MYC site and the MYB recognition site function as cis-acting elements in the dehydration-induced expression of the @entity22714 gene. A cDNA encoding a MYC-related DNA binding protein was isolated by DNA-ligand binding screening, using the 67-bp region as a probe, and designated @entity15020 . The @entity15020 cDNA encodes a 68-kD protein that has a typical DNA binding domain of a basic region helix-loop-helix @entity368 zipper motif in MYC-related transcription factors. The @entity15020 protein binds specifically to the first MYC recognition site in the 67-bp fragment. RNA gel blot analysis revealed that transcription of the @entity15020 gene is induced by dehydration stress and ABA treatment, and its induction precedes that of @entity22714 . We have reported a drought- and ABA-inducible gene that encodes the MYB-related protein @entity60896 . In a transient transactivation experiment using @entity958 leaf protoplasts, we demonstrated that both the @entity15020 and @entity60896 proteins activate transcription of the @entity22714 promoter fused to the beta-glucuronidase reporter gene. These results indicate that both the @entity15020 (MYC) and @entity60896 (MYB) proteins function as transcriptional activators in the dehydration- and ABA-inducible expression of the @entity22714 gene.

Role of XXXX MYC and MYB homologs in drought- and @entity2271 -regulated gene expression.

@entity2272 :: ('CHEBI:2365', 'Chemical') :: ['ABA'] @entity286 :: ('4097', 'Species') :: ['tobacco'] @entity2271 :: ('MESH:D000040', 'Chemical') :: ['abscisic acid'] @entity368 :: ('CHEBI:25017', 'Chemical') :: ['leucine'] @entity958 :: ('3702', 'Species') :: ['Arabidopsis'] @entity60896 :: ('819332(Tax:3702)', 'Gene') :: ['ATMYB2'] @entity15020 :: ('840158(Tax:3702)', 'Gene') :: ['rd22BP1'] @entity22714 :: ('832636(Tax:3702)', 'Gene') :: ['rd22']
@entity958 :: (3702,Species) :: ['arabidopsis']
