ABSCISIC ACID REPRESSOR-1 (ABR1), an APETALA2 (AP2) domain containing transcription factor (TF) contribute important function against variety of external cues. Here, we report an AP2/ERF TF, AtERF60 that serves as an important regulator of ABR1 gene. AtERF60 is induced in response to drought, salt, abscisic acid (ABA), salicylic acid (SA), and bacterial pathogen PstDC3000 infection. AtERF60 interacts with DEHYDRATION RESPONSE ELEMENTS (DRE1/2) and GCC box indicating its ability to regulate multiple responses. Overexpression of AtERF60 results in the drought and salt stress tolerant phenotype in both seedling and mature Arabidopsis plants in comparison with the wild type (WT-Col). However, mutation in AtERF60 showed hyperactive response against drought and salt stress in comparison with its overexpression and WT. Microarray and qRT-PCR analysis of overexpression and mutant lines indicated that AtERF60 regulates both abiotic and biotic stress inducible genes. One of the differentially expressing transcripts was ABR1 and we found that AtERF60 interacts with the DRE cis-elements present in the ABR1 promoter. The mutation in AtERF60 showed ABA hypersensitive response, increased ABA content, and reduced susceptibility to PstDC3000. Altogether, we conclude that AtERF60 represses ABR1 transcript by binding with the DRE cis-elements and modulates both abiotic and biotic stress responses in Arabidopsis.
Overexpression of the ChVDE gene, encoding a violaxanthin de-epoxidase, improves tolerance to drought and salt stress in transgenic Arabidopsis
