The R2R3-type MYB gene OsMYB91 has a function in coordinating plant growth and salt stress tolerance in rice
The R2R3-type MYB gene OsMYB91 has a function in coordinating plant growth and salt stress tolerance in rice
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R2R3型MYB基因OsMYB91具有协调水稻植物生长和耐盐胁迫的功能
DOI：
10.1016/j.plantsci.2015.03.023
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发表时间：
2015
期刊：
影响因子：
5.2
通讯作者：
Zhao Yu
中科院分区：
文献类型：
--
作者：
Zhu Ning;Cheng Saifeng;Liu Xiaoyun;Du Hao;Dai Mingqiu;Zhou Dao-Xiu;Yang Wenjing;Zhao Yu
植物进化出许多不同的机制来响应和适应非生物胁迫以维持其生存。然而，参与协调非生物胁迫耐受性和植物生长的调节机制尚未完全了解。本研究对水稻R2R3型MYB转录因子OsMYB91的功能进行了初步探讨，OsMYB91在非生物胁迫，特别是盐胁迫下受到诱导。对该基因的染色质结构分析表明，盐胁迫导致启动子区域DNA甲基化的快速去除和该位点组蛋白修饰的快速变化。在对照条件下，过量表达OsMYB91的植物表现出降低的植物生长和内源阿坝积累。在盐胁迫下，过量表达的植株表现出更强的耐盐性，脯氨酸含量显著增加，活性氧吸收能力显著增强，OsP5CS1和LOC_Os03g44130的诱导率也比野生型高，而RNAi植株对盐胁迫的敏感性较低。此外，OsMYB91的表达也受到其他非生物胁迫和激素处理的诱导。更有趣的是，SLR1，水稻同源的拟南芥DELLA基因，已被证明整合内源发育信号与不利的环境条件，高度诱导OsMYB91过表达，而盐诱导的SLR1表达在RNAi植物中受损。这些结果表明，OsMYB91是一个胁迫响应基因，可能通过调控SLR 1的表达来协调水稻对非生物胁迫的耐受性和植物生长。
Plants have evolved a number of different mechanisms to respond and to adapt to abiotic stress for their survival. However, the regulatory mechanisms involved in coordinating abiotic stress tolerance and plant growth are not fully understood. Here, the function of OsMYB91, an R2R3-type MYB transcription factor of rice was explored.OsMYB91was induced by abiotic stress, especially by salt stress. Analysis of chromatin structure of the gene revealed that salt stress led to rapid removal of DNA methylation from the promoter region and rapid changes of histone modifications in the locus. Plants over-expressingOsMYB91showed reduced plant growth and accumulation of endogenous ABA under control conditions. Under salt stress, the over-expression plants showed enhanced tolerance with significant increases of proline levels and a highly enhanced capacity to scavenge active oxygen as well as the increased induction ofOsP5CS1andLOC_Os03g44130compared to wild type, while RNAi plants were less sensitive. In addition, expression ofOsMYB91was also induced by other abiotic stresses and hormone treatment. More interestingly,SLR1, the rice homolog of ArabidopsisDELLAgenes that have been shown to integrate endogenous developmental signals with adverse environmental conditions, was highly induced byOsMYB91over-expression, while the salt-induction ofSLR1expression was impaired in the RNAi plants. These results suggested thatOsMYB91was a stress-responsive gene that might be involved in coordinating rice tolerance to abiotic stress and plant growth by regulatingSLR1expression.