植物生长和抗逆性的动态平衡是植物增产抗逆的关键，也是目前植物逆境生物学研究的重要方向。促生长激素油菜素内酯(BR)在植物协调生长和抗逆性平衡过程中的作用备受关注，阐明BR调控植物响应高温胁迫以及协调植物生长与耐热性平衡的机制对于作物抗逆稳产实践具有重要指导意义。项目前期研究结果表明，BR信号在BIN2和BES1两个节点上参与调控植物响应高温胁迫，BIN2正调控而BES1负调控植物耐热性；蛋白互作筛选发现BES1与热激信号调控因子DREB2A形成复合物共同调控下游基因表达。在此基础上，本项目拟开展如下研究：1）通过转录组学、分子生物学、生物化学等手段解析BR信号通过BES1与热激调控因子调控植物生长和热胁迫响应动态平衡的机制；2）建立BIN2介导BR信号和热胁迫信号交叉互作的调控模型。旨在阐释植物整合BR信号和热胁迫信号适应环境温度变化的分子机制，为下一步培育耐热高产作物奠定坚实的理论基础。

The trade-off between growth and stress resistance is crucial for high yield of crops under stress conditions. Brassinosteroids (BRs) are one major family of growth-promoting plant hormones. Recently, the function of BRs in balancing plant growth and survival are paid much attention in botany field. However, the mechanisms in which BRs regulate plant high temperature stress responses and coordinate growth-thermotolerance balance has remained elusive. Our preliminary data indicated that two important regulators of BR signaling pathway, BIN2 and BES1, act as key nodes mediating the crosstalk between the BR signaling and heat responses, BIN2 positively and BES1 negatively regulates plant thermotolerance. Further, we indentified one of the BES1 interactors as DREB2A, a key regulator of heat responses, suggesting BES1-DREB2A maybe integrate BR signaling and heat response to control plant growth and thermotolerance. Therefore, in this project, we plan to take advantage of transcriptomics, molecular biology and biochemistry approaches to explore the molecular mechanism underlying BES1-DREB2A coordinating the balance between BR-promoted growth and heat response, and investigate the crosstalk between BR signaling and heat signaling mediated by BIN2. These results will help us to clarify the mechanism in which BR signaling coordinates the trade-off between growth and thermotolerance, and provide theory basis for breeding heat-resistance high-yield crops.