MYB96 recruits the HDA15 protein to suppress negative regulators of ABA signaling in Arabidopsis

• Published in: Nature communications Vol. 10; no. 1; p. 1713
• Main Authors: Lee, Hong Gil, Seo, Pil Joon
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.04.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 38; 38/1; 38/15; 38/35; 38/39; 38/88; 631/337/572/2102; 631/449/2661/2146; 631/449/2675; 64; 96; 96/95; Abscisic acid; Abscisic Acid - metabolism; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Catalysis; Deficient mutant; Derepression; Down-regulation; Drought; Gene expression; Gene Expression Regulation, Plant; Genes; Genetic analysis; Genotype; Guanosine triphosphatases; Histone Deacetylases - genetics; Histone Deacetylases - metabolism; Histone H3; Histones - metabolism; Humanities and Social Sciences; Molecular modelling; multidisciplinary; Mutants; Mutation; Plants, Genetically Modified - metabolism; Promoter Regions, Genetic; Proteins; Regulators; Reproducibility of Results; Science; Science (multidisciplinary); Sensitivity; Signal Transduction; Signaling; Transcription activation; Transcription Factors - genetics; Transcription Factors - metabolism
• DOI: 10.1038/s41467-019-09417-1
• ISSN: 2041-1723

Unlike activation of target genes in response to abscisic acid (ABA), how MYB96 transcription factor represses ABA-repressible genes to further enhance ABA responses remains unknown. Here, we show MYB96 interacts with the histone modifier HDA15 to suppress negative regulators of early ABA signaling. The MYB96-HDA15 complex co-binds to the promoters of a subset of RHO GTPASE OF PLANTS ( ROP ) genes, ROP6 , ROP10 , and ROP11 , and represses their expression by removing acetyl groups of histone H3 and H4 from the cognate regions, particularly in the presence of ABA. In support, HDA15 -deficient mutants display reduced ABA sensitivity and are susceptible to drought stress with derepression of the ROP genes, as observed in the myb96-1 mutant. Biochemical and genetic analyses show that MYB96 and HDA15 are interdependent in the regulation of ROP suppression. Thus, MYB96 confers maximal ABA sensitivity by regulating both positive and negative regulators of ABA signaling through distinctive molecular mechanisms. MYB96 can regulate both positive and negative regulators of ABA signaling to maximize plant drought tolerance. Here, the authors show that MYB96 represses expression of ABA negative regulators in Arabidopsis by interacting with HDA15 and promoting histone deacetylation at the cognate regions.