Baek Dongwon, Shin Gilok, Kim Min Chul, Shen Mingzhe, Lee Sang Yeol, Yun Dae-Jin
Division of Applied Life Science (BK21plus program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea.
Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea.
Front Plant Sci. 2020 Feb 25;11:143. doi: 10.3389/fpls.2020.00143. eCollection 2020.
Drought stress, a major environmental factor, significantly affects plant growth and reproduction. Plants have evolved complex molecular mechanisms to tolerate drought stress. In this study, we investigated the function of the RPD3-type HISTONE DEACETYLASE 9 (HDA9) in response to drought stress. The loss-of-function mutants and were insensitive to abscisic acid (ABA) and sensitive to drought stress. The ABA content in the mutant was reduced in wild type (WT) plant. Most histone deacetylases in animals and plants form complexes with other chromatin-remodeling components, such as transcription factors. In this study, we found that HDA9 interacts with the ABA INSENSITIVE 4 (ABI4) transcription factor using a yeast two-hybrid assay and coimmunoprecipitation. The expression of and , which encode (+)-ABA 8'-hydroxylases, key enzymes in ABA catabolic pathways, was highly induced in , , , and mutants upon drought stress. Chromatin immunoprecipitation and quantitative PCR showed that the HDA9 and ABI4 complex repressed the expression of and by directly binding to their promoters in response to drought stress. Taken together, these data suggest that HDA9 and ABI4 form a repressive complex to regulate the expression of and in response to drought stress in .
干旱胁迫作为一个主要的环境因素，显著影响植物的生长和繁殖。植物已经进化出复杂的分子机制来耐受干旱胁迫。在本研究中，我们调查了RPD3型组蛋白去乙酰化酶9（HDA9）在响应干旱胁迫中的功能。功能缺失突变体对脱落酸（ABA）不敏感，但对干旱胁迫敏感。突变体中的ABA含量在野生型（WT）植株中降低。动植物中的大多数组蛋白去乙酰化酶与其他染色质重塑成分（如转录因子）形成复合物。在本研究中，我们通过酵母双杂交试验和免疫共沉淀发现HDA9与ABA不敏感4（ABI4）转录因子相互作用。编码ABA分解代谢途径关键酶（+）-ABA 8'-羟化酶的和的表达在干旱胁迫下在、、和突变体中被高度诱导。染色质免疫沉淀和定量PCR表明，HDA9和ABI4复合物通过在干旱胁迫下直接结合其启动子来抑制和的表达。综上所述，这些数据表明HDA9和ABI4形成一个抑制复合物，以响应中的干旱胁迫来调节和的表达。
