韩召奋等《Journal of Experimental Botany》2022年

论文题目：AtHD2D, A Plant-specific Histone Deacetylase Involved in Abscisic Acid Response and Lateral Root Development

论文作者：Zhang, Zhaochen;Yang, Weixia;Chu, Yueyang;Yin, Xiaotong;Liang, Yueqi;Wang, Qiuping;Wang, Lei;Han, Zhaofen

论文摘要：

In eukaryotes, Histone acetylation levels directly regulate downstream gene expression. As a plant-specific Histone deacetylase (HDAC), HD2D is involved in plant development and abiotic stress. However, the response of HD2D to drought stress and its interaction proteins are still unclear. In this study, HD2D gene expression patterns were analyzed, revealing that the HD2D gene was highly expressed in roots and rosette leaves, but poorly expressed in the other tissues examined. The HD2D gene expression was induced by D-mannitol. The study investigated the responses of the wild-type plant (WT), HD2D-overexpression lines, and hd2d mutants to drought stress, further demonstrating that HD2D-overexpressing lines showed Abscisic acid (ABA) hypersensitivity and drought tolerance, and these phenotypes were not present in hd2d mutants. RNA-seq analysis revealed the transcriptome changes by HD2D under drought stress and showed that HD2D responded to drought stress through the ABA signaling pathway. In addition, the study demonstrated that CASEIN KINASE II (CKA4) directly interacted with HD2D. The phosphorylation of Ser residues of HD2D by CKA4 enhanced HD2D enzymic activity. Furthermore, the phosphorylation of HD2D was shown to contribute to lateral root development and ABA sensing in Arabidopsis, but, these phenotypes could not be reproduced by the overexpression of Ser-phosphorylated mutant of HD2D. Collectively, this study suggested that the HD2D responded to drought stress by regulating the ABA signaling pathway and the expression of drought stress-related genes. The regulation mechanism of HD2D mediated by CKII phosphorylation provides new insights for its response to ABA and lateral root development in Arabidopsis.

在真核生物中，组蛋白乙酰化水平直接调控下游基因的表达。HD2D作为植物特有的组蛋白去乙酰化酶(HDAC)，参与植物的生长发育和非生物胁迫反应。然而，HD2D对干旱胁迫的响应及其互作用蛋白目前仍不清楚。本研究通过对HD2D基因表达谱的分析，发现HD2D基因在根系和莲座叶中高表达，而在其他组织中低表达。HD2D基因表达受到D-甘露醇的诱导。通过对野生型植物(WT)、HD2D过表达系和hd2d突变体对干旱胁迫的响应研究，进一步发现HD2D过表达株系表现出对ABA敏感和耐旱性，而这些表型在hd2d突变体中不存在。RNA-seq分析发现干旱胁迫下HD2D的转录组变化表明：HD2D通过ABA信号通路响应干旱胁迫。此外，研究表明，CASEIN KINASE II (CKA4)与HD2D直接相互作用。CKA4对HD2D中的丝氨酸残基的磷酸化增强了HD2D的酶活性。此外，HD2D的磷酸化被证明有助于拟南芥的侧根发育和对ABA的感知，但这些表型不能通过HD2D的ser磷酸化突变体的过表达来重现。综上所述，本研究表明HD2D通过调节ABA信号通路和干旱胁迫相关基因的表达来应对干旱胁迫。CKII磷酸化介导的HD2D调控机制为其对ABA的响应和拟南芥侧根发育提供了新的认识。

文章链接：https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erac381/6705480