BES/BZR Transcription Factor TaBZR2 Positively Regulates Drought Responses by Activation of TaGST1
作 者：Xiao-Yu Cui, Yuan Gao, Jun Guo, Tai-fei Yu, Wei-Jun Zheng, Yong-Wei Liu, Jun Chen, Zhao-Shi Xu, You-Zhi Ma
文章摘要：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, TaBZR2-overexpressing plants exhibited drought tolerant phenotypes, whereas down-regulation of TaBZR2 in wheat (Triticum aestivum) 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 TaGST1, which functions positively in scavenging drought-induced superoxide anions (O2-). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O2- scavenging and anti-oxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating TaGST1 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.