Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
Plant Physiol. 2019 May;180(1):605-620. doi: 10.1104/pp.19.00100. Epub 2019 Mar 6.
BRI1-EMS suppressor (BES)/brassinazole-resistant (BZR) family transcription factors are involved in a variety of physiological processes, but the biological functions of some BES/BZR transcription factors remain unknown; moreover, it is not clear if any of these proteins function in the regulation of plant stress responses. Here, wheat () brassinazole-resistant 2 ()-overexpressing plants exhibited drought tolerant phenotypes, whereas downregulation of in wheat by RNA interference resulted in elevated drought sensitivity. electrophoretic mobility shift assay and luciferase reporter analysis illustrate that TaBZR2 directly interacts with the gene promoter to activate the expression of glutathione s-transferase-1 (), which functions positively in scavenging drought-induced superoxide anions (O ). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O scavenging and antioxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating and mediates the crosstalk between BR and drought signaling pathways. Our results thus provide new insights into the mechanisms underlying how BES/BZR family transcription factors contribute to drought tolerance in wheat.
BRI1-EMS 抑制物（BES）/油菜素内酯抗性（BZR）家族转录因子参与多种生理过程，但某些 BES/BZR 转录因子的生物学功能仍不清楚；此外，这些蛋白是否参与植物应激反应的调节也不清楚。在这里，小麦油菜素内酯抗性 2（）过表达植株表现出耐旱表型，而通过 RNA 干扰下调小麦中的则导致干旱敏感性增加。电泳迁移率变动分析和荧光素酶报告基因分析表明，TaBZR2 直接与基因启动子相互作用，激活谷胱甘肽 s-转移酶-1（）的表达，该基因在清除干旱诱导的超氧阴离子（O）方面发挥积极作用。此外，TaBZR2 作为油菜素内酯（BR）信号转导的正调控因子。外源 BR 处理增强了 TaBZR2 介导的 O 清除和抗氧化酶基因的表达。总之，我们证明了 BES/BZR 家族转录因子 TaBZR2 通过激活和介导 BR 与干旱信号通路之间的串扰，积极参与干旱反应。我们的研究结果为 BES/BZR 家族转录因子如何促进小麦耐旱性提供了新的见解。
