玉米转录因子ZmCCT逆境应答的表观调控机制及抗逆作用机理研究

Maize is the largest cultivated crop worldwide and plays key role towards food security around the world. In a previous work, we identified a QTL named ZmCCT, which encodes a transcription factor and is important for resistance to stalk rot in maize. Further, a polymorphic CACTA-like transposable element (TE1) was found to locate at the upstream of ZmCCT. TE1 insertion changed epigenetic modifications and triggered a drastic but transient induction gene expression of ZmCCT, resulting in susceptibility to stalk rot disease. We proved that this transposon directed epigenetic regulation in ZmCCT upon pathogen challenge. Previous studies have showed that ZmCCT tended to have pleiotropism. We found that ZmCCT could respond to low nitrogen and high salt stress conditions and enhance the adaption to abiotic stress of maize. At present, the roles and regulatory mechanisms of maize ZmCCT gene in plant stress tolerance were still unknown. In this project, we will further plan to integrate the approaches of epigenetic and biochemical strategies to discover the mechanisms of transposon-directed epigenetic regulation of ZmCCT，which proteins interact with ZmCCT, what downstream targets regulated by ZmCCT and what are their signaling roles during the resistance process. Together, this work will contribute to analyze the stress tolerance mechanism of ZmCCT gene in maize. Our study will provide novel views to understand mechanism to control Gibberella stalk rot and other stress conditions, and will also provide new inspiration for deploying broad-spectrum resistance maize varieties.

玉米是世界上广泛种植的粮、饲兼用的重要作物。玉米茎腐病是世界各玉米产区普遍发生的、危害严重的土传真菌病害。前期,我们克隆到玉米抗茎腐病基因ZmCCT，并发现其调控区域存在一个转座子TE1的插入。TE1的插入介导了ZmCCT迅速响应病原菌侵染的动态表观遗传调控机制。此外，ZmCCT基因区段是许多重要农艺性状QTL定位的热点区域。除抗病外，我们发现ZmCCT还参与低氮和高盐等逆境胁迫,具有一因多效性。目前，ZmCCT基因如何参与抗病、低氮和高盐等逆境胁迫的分子作用机理尚不清楚。本研究将利用表观遗传学及生物化学等研究方法，进一步鉴定TE1插入对ZmCCT基因响应低氮和高盐逆境胁迫的表观调控机制；筛选并鉴定ZmCCT互作蛋白复合体及保守的氨基酸序列；明确其靶基因及其可能参与的逆境信号传导途径；探讨ZmCCT介导的抗逆分子调控机制。本研究将为创新抗逆种质资源和培育持久抗性品种提供理论基础。

玉米是世界上广泛种植的粮、饲兼用的重要作物。玉米茎腐病是世界各玉米产区普遍发生.的、危害严重的土传真菌病害。前期,我们克隆到玉米抗茎腐病基因ZmCCT，并发现其调控区域.存在一个转座子TE1的插入。TE1的插入介导了ZmCCT迅速响应病原菌侵染的动态表观遗传调控.机制。此外，ZmCCT基因区段是许多重要农艺性状QTL定位的热点区域。除抗病外，我们发现Zm.CCT还参与低氮和高盐等逆境胁迫,具有一因多效性。目前，ZmCCT基因如何参与抗病、低氮和.高盐等逆境胁迫的分子作用机理尚不清楚。本研究将利用表观遗传学及生物化学等研究方法，.进一步鉴定TE1插入对ZmCCT基因响应低氮和高盐逆境胁迫的表观调控机制；筛选并鉴定ZmCCT.互作蛋白复合体及保守的氨基酸序列；明确其靶基因及其可能参与的逆境信号传导途径；探讨.ZmCCT介导的抗逆分子调控机制。本研究将为创新抗逆种质资源和培育持久抗性品种提供理论.基础