Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Plant Mol Biol. 2020 Sep;104(1-2):67-79. doi: 10.1007/s11103-020-01024-9. Epub 2020 Jul 3.
Acetylation and deacetylation of histones are important for regulating a series of biological processes in plants. Histone deacetylases (HDACs) control the histone deacetylation that plays an important role in plant response to abiotic stress. In our study, we show the evidence that GhHDT4D (a member of the HD2 subfamily of HDACs) is involved in cotton (Gossypium hirsutum) response to drought stress. Overexpression of GhHDT4D in Arabidopsis increased plant tolerance to drought, whereas silencing GhHDT4D in cotton resulted in plant sensitivity to drought. Simultaneously, the H3K9 acetylation level was altered in the GhHDT4D silenced cotton, compared with the controls. Further study revealed that GhHDT4D suppressed the transcription of GhWRKY33, which plays a negative role in cotton defense to drought, by reducing its H3K9 acetylation level. The expressions of the stress-related genes, such as GhDREB2A, GhDREB2C, GhSOS2, GhRD20-1, GhRD20-2 and GhRD29A, were significantly decreased in the GhHDT4D silenced cotton, but increased in the GhWRKY33 silenced cotton. Given these data together, our findings suggested that GhHDT4D may enhance drought tolerance by suppressing the expression of GhWRKY33, thereby activating the downstream drought response genes in cotton.
组蛋白的乙酰化和去乙酰化对于调控植物中的一系列生物过程非常重要。组蛋白去乙酰化酶（HDACs）控制组蛋白去乙酰化，在植物应对非生物胁迫中起着重要作用。在我们的研究中，我们证明了 GhHDT4D（HDACs 的 HD2 亚家族的一个成员）参与棉花（Gossypium hirsutum）对干旱胁迫的响应。在拟南芥中过表达 GhHDT4D 增加了植物对干旱的耐受性，而在棉花中沉默 GhHDT4D 则导致植物对干旱敏感。同时，与对照相比，沉默 GhHDT4D 的棉花中 H3K9 乙酰化水平发生了改变。进一步的研究表明，GhHDT4D 通过降低其 H3K9 乙酰化水平来抑制 GhWRKY33 的转录，GhWRKY33 在棉花对干旱的防御中起负作用。GhDREB2A、GhDREB2C、GhSOS2、GhRD20-1、GhRD20-2 和 GhRD29A 等与应激相关的基因在 GhHDT4D 沉默的棉花中的表达显著降低，但在 GhWRKY33 沉默的棉花中的表达增加。综合这些数据，我们的研究结果表明，GhHDT4D 可能通过抑制 GhWRKY33 的表达来增强耐旱性，从而激活棉花中下游的干旱响应基因。
