Promoter-associated histone acetylation is involved in the osmotic stress-induced transcriptional regulation of the maize ZmDREB2A gene.
Promoter-associated histone acetylation is involved in the osmotic stress-induced transcriptional regulation of the maize ZmDREB2A gene.
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DOI：
10.1111/ppl.12136
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发表时间：
2014-08
影响因子：
6.4
通讯作者：
Lin Zhao;Pu Wang;Shihan Yan;Fei Gao;Hui Li;Haoli Hou;Qi Zhang;Junjun Tan;Lijia Li
中科院分区：
文献类型：
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作者：
Lin Zhao;Pu Wang;Shihan Yan;Fei Gao;Hui Li;Haoli Hou;Qi Zhang;Junjun Tan;Lijia Li
表观遗传修饰在植物逆境胁迫诱导基因表达的转录调控中起着关键作用。在这项研究中，我们表明，在甘露醇处理（模拟渗透胁迫）后，玉米幼苗基因组中组蛋白H3赖氨酸9（H3K9）和H4赖氨酸5（H4K5）的整体乙酰化水平增加。甘露醇处理显著诱导玉米渗透胁迫响应基因玉米脱水响应元件结合蛋白2A（ZmDREB2A）的上调，而脱落酸（阿坝）没有导致该基因的诱导。在渗透胁迫条件下施加外源阿坝强烈抑制了ZmDREB2A基因的诱导。染色质免疫沉淀和染色质可及性的实时PCR实验表明，ZmDREB2A基因的启动子区域被迅速超乙酰化和甘露醇处理后的去致密化，这表明启动子区域准备组蛋白乙酰化，以允许快速诱导ZmDREB2A基因。然而，在渗透胁迫条件下，阿坝处理降低乙酰化状态和染色质可及性微球菌核酸酶。这些结果表明，渗透胁迫通过增加与ZmDREB2A启动子区域相关的乙酰化组蛋白H3K9和H4K5的水平来激活ZmDREB2A基因的转录。
Epigenetic modifications play a key role in the transcriptional regulation of stress-induced gene expression in plants. In this study, we showed that the overall acetylation levels of histone H3 lysine 9 (H3K9) and H4 lysine 5 (H4K5) in the genome were increased in maize seedlings after mannitol treatment (to mimic osmotic stress). Mannitol treatment significantly induced the upregulation of the maize osmotic stress responsive gene Zea mays dehydration-responsive element binding protein 2A (ZmDREB2A), whereas abscisic acid (ABA) did not result in the induction of this gene. The application of exogenous ABA under osmotic stress conditions strongly repressed the induction of the ZmDREB2A gene. Chromatin immunoprecipitation and chromatin accessibility by real-time PCR experiments revealed that the promoter region of the ZmDREB2A gene was quickly hyperacetylated and decondensed after the mannitol treatment, suggesting that the promoter region is poised for histone acetylation to allow for fast induction of the ZmDREB2A gene. However, under osmotic stress conditions, the ABA treatment decreased the acetylation status and chromatin accessibility to micrococcal nuclease. These results suggest that osmotic stress activates the transcription of the ZmDREB2A gene by increasing the levels of acetylated histones H3K9 and H4K5 associated with the ZmDREB2A promoter region.