干旱和高温胁迫是威胁植物生长发育及作物产量的主要逆境因子。拟南芥DREB2A是响应干旱及高温胁迫的关键转录因子，但其在胁迫条件下如何维持蛋白质稳定性并被激活其转录活性的机制尚不清楚。SUMO 化是影响植物生长发育和非生物胁迫的重要调控方式。最近我们发现，SUMO E2 结合酶AtSCE1在胁迫条件下能够与DREB2A相互作用，且DREB2A能被SUMO化修饰，SUMO化增强了其在干旱及高温条件下的稳定性。上述结果表明，SUMO化在胁迫条件下对调控DREB2A蛋白的稳定性及活性具有重要的作用。在此基础上，本项目拟利用遗传学、分子生物学及生物化学方法，深入研究SUMO化修饰增强DREB2A稳定性及调控其转录活性来响应胁迫的具体分子机制。通过对SUMO化修饰调控DREB2A功能的阐释，揭示SUMO途径与DREB2A途径之间的关系，进一步完善DREB2A响应干旱及高温胁迫的转录调控网络。

Drought and heat stresses are the main factors that threaten plant growth and crop yield. DREB2A is a key transcription factor responding to drought and heat stresses in Arabidopsis, but the mechanisms of maintaining its protein stability and activating its transcription factor function under stress conditions are unclear. Sumoylation is an important regulating process which functions in plant growth and development as well as abiotic stress. We have recently found that SUMO E2 conjugation enzyme AtSCE1 interacted with DREB2A under stress conditions, and DREB2A can be modified by SUMO, and sumoylation has enhanced its stability under drought and heat conditions. These results suggested that sumoylation may play an important role in regulating the stability and activity of DREB2A protein. Based on these data, we will study the molecular mechanisms of DREB2A stability and transcriptional activity regulated by sumoylation in response to drought and heat stresses using moleculars biology, genetics and biochemical methods. The results from this study will not only clarify the interaction between SUMO pathway and DREB2A pathway, but also improve the transcriptional regulation network of DREB2A in response to drought and heat stresses.