Plants have evolved numerous mechanisms that assist them in withstanding environmental stresses. Histone deacetylases (HDACs) play crucial roles in plant stress responses; however, their regulatory mechanisms remain poorly understood. Here, we explored the function of HDA710/OsHDAC2, a member of the HDAC RPD3/HDA1 family, in stress tolerance in rice (Oryza sativa). We established that HDA710 localizes to both the nucleus and cytoplasm and is involved in regulating the acetylation of histone H3 and H4, specifically targeting H4K5 and H4K16 under normal conditions. HDA710 transcript accumulation levels were strongly induced by abiotic stresses including drought and salinity, as well as by the phytohormones jasmonic acid (JA) and abscisic acid (ABA). hda710 knockout mutant plants showed enhanced salinity tolerance and reduced ABA sensitivity, whereas transgenic plants overexpressing HDA710 displayed the opposite phenotypes. Moreover, ABA‐ and salt‐stress‐responsive genes, such as OsLEA3, OsABI5, OsbZIP72, and OsNHX1, were upregulated in hda710 compared with wild‐type plants. These expression differences corresponded with higher levels of histone H4 acetylation in gene promoter regions in hda710 compared with the wild type under ABA and salt‐stress treatment. Collectively, these results suggest that HDA710 is involved in regulating ABA‐ and salt‐stress‐responsive genes by altering H4 acetylation levels in their promoters.

中文翻译：

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组蛋白脱乙酰基酶HDA710通过调节水稻中的ABA信号传导来控制盐耐受性

植物已经进化出许多机制来帮助植物抵御环境压力。组蛋白脱乙酰基酶（HDACs）在植物胁迫反应中起着至关重要的作用。然而，他们的监管机制仍然知之甚少。在这里，我们探讨了HDAC RPD3 / HDA1家族成员HDA710 / OsHDAC2在水稻（Oryza sativa）的胁迫耐受性中的功能。我们确定，HDA710既定位于细胞核，又定位于细胞质，并参与调节组蛋白H3和H4的乙酰化，特别是在正常情况下靶向H4K5和H4K16。非生物胁迫（包括干旱和盐碱化）以及植物激素茉莉酸（JA）和脱落酸（ABA）强烈诱导了HDA710转录物的积累水平。hda710敲除突变体植物显示出更高的盐度耐受性和降低的ABA敏感性，而过表达HDA710的转基因植物表现出相反的表型。此外，ABA-和盐胁迫应答基因，如OsLEA3，OsABI5，OsbZIP72，和OsNHX1，是在上调HDA710与野生型植物相比较。与在ABA和盐胁迫处理下的野生型相比，hda710基因启动子区域中的组蛋白H4乙酰化水平较高，这些表达差异与之相对应。总的来说，这些结果表明，HDA710通过改变启动子中的H4乙酰化水平，参与调节ABA和盐胁迫响应基因。