Expression of AhDREB1, an AP2/ERF Transcription Factor Gene from Peanut, Is Affected by Histone Acetylation and Increases Abscisic Acid Sensitivity and Tolerance to Osmotic Stress in Arabidopsis

Abstract

Drought stress negatively affects plant growth and development. An increasing number of reports have revealed the involvement of APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription factors (TFs) in biotic and abiotic stress regulation in plants. However, research on these TFs in the peanut plant <i>(Arachis hypogaea)</i> has been limited. Here, we isolated a full-length coding sequence (CDS) of the AP2/ERF family gene <i>AhDREB1</i> from the peanut plant and showed that its expression was induced by Polyethylene Glycol (PEG) 6000 and exogenous abscisic acid (ABA) treatment. When overexpressed in <i>Arabidopsis</i>, <i>AhDREB1</i> increased both ABA levels and ABA sensitivity, affected the ABA signaling pathway and increased the expression of downstream drought stress-related genes <i>RD29A</i>, <i>P5CS1</i>, <i>P5CS2</i> and <i>NCED1</i>. These results demonstrate that <i>AhDREB1</i> can improve tolerance to drought via the ABA-dependent pathway in <i>Arabidopsis</i>. In the peanut plant, the specific histone deacetylases (HDACs) inhibitor trichostatin A (TSA) promotes <i>AhDREB1</i> transcription and the enrichment level of H3ac was increased in regions of the <i>AhDREB1</i> gene during TSA and PEG treatment. In summary, histone acetylation can affect the expression of <i>AhDREB1</i> under osmotic stress conditions, thereby improving plant drought resistance.