A brassinosteroid responsive miRNA-target module regulates gibberellin biosynthesis and plant development
A brassinosteroid responsive miRNA-target module regulates gibberellin biosynthesis and plant development
复制标题
油菜素类固醇响应性 miRNA 靶标模块调节赤霉素生物合成和植物发育
DOI：
10.1111/nph.15331
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发表时间：
2018-10-01
期刊：
影响因子：
9.4
通讯作者：
Li, Jianxiong
中科院分区：
文献类型：
--
作者：
Gao, Jing;Chen, Hong;Li, Jianxiong
植物的生长和发育是由激素高度协调的，包括油菜素类固醇（BR）和赤霉素（GA）。虽然在理解BR和GA的基本信号转导方面已经取得了很大进展，但它们之间的关系在水稻中仍然是难以捉摸的。在这里，我们表明BR抑制OsmiR159d的水平，OsmiR159d切割靶OsGAMYBL2基因。OsmiR159d-OsGAMYBL 2对作为早期BR应答模块发挥作用，通过结合到这些基因的启动子来调节参与BR信号传导的BR调节基因BU1以及GA生物合成中的两个基因CPS 1和GA 3ox 2的表达。此外，OsGSK2是BR信号传导中的关键负向参与者，其与OsGAMYBL2相互作用并阻止OsGAMYBL2在24-表油菜素处理下降解，而SLR1是负向调节GA信号传导的水稻DELLA蛋白，其与OsGAMYBL2相互作用并阻止OsGAMYBL2与靶基因启动子结合。GA信号转导诱导OsGAMYBL 2的降解，并因此增强BR信号转导。这些结果表明，BR-响应模块作为一个共同的组件在BR和GA途径中发挥作用，它连接BR信号和GA生物合成，从而协调BR和GA在植物生长发育中的调节。
Plant growth and development are highly coordinated by hormones, including brassinosteroid (BR) and gibberellin (GA). Although much progress has been made in understanding the fundamental signaling transduction in BR and GA, their relationship remains elusive in rice. Here, we show that BR suppresses the level of OsmiR159d, which cleaves the target OsGAMYBL2 gene. The OsmiR159d-OsGAMYBL2 pair functions as an early BR-responsive module regulating the expression of BU1, a BR-regulated gene involved in BR signaling, and CPS1 and GA3ox2, two genes in GA biosynthesis, by binding to the promoters of these genes. Furthermore, OsGSK2, a key negative player in BR signaling, interacts with OsGAMYBL2 and prevents it from being degraded under 24-epibrassinolide treatment, whereas SLR1, a rice DELLA protein negatively regulating GA signaling, interacts with OsGAMYBL2 and prevents OsGAMYBL2 from binding to the target gene promoter. GA signaling induces degradation of OsGAMYBL2 and, consequently, enhances BR signaling. These results demonstrate that a BR-responsive module acts as a common component functioning in both BR and GA pathways, which connects BR signaling and GA biosynthesis, and thus coordinates the regulation of BR and GA in plant growth and development.