MORC1和bZIP18协同调控植物防卫基因表达的分子机制研究

拟南芥MORC1参与免疫反应，在病原菌侵染时，它从NLR蛋白互作态变成游离态，进入细胞核，增强防卫基因表达，但MORC1在转录水平上调控防卫基因表达的机制尚不清楚。我们前期筛选到一个与MORC1互作的转录因子bZIP18，并通过多种手段验证了它们的互作；通过遗传学手段发现bZIP18负调控植物免疫。本项目拟进一步分析bzip18突变体对不同病原菌抗性，以及对PTI和ETI信号途径的影响，明确其在植物免疫中的作用；通过MORC1和bZIP18的染色质免疫沉淀测序分析，挖掘MORC1和bZIP18直接调控的防卫基因；通过解析MORC1和bZIP18的互作模式以及二者的调控关系，揭示MORC1和bZIP18协同调控防卫基因表达的机制。项目将阐明bZIP18作为一个新免疫调控因子的作用机理，进一步完善MORC1参与植物免疫的分子调控网络。

Arabidopsis MORC1 is involved in plant immunity. Upon infection, MORC1 disassociates with NLR proteins and translocates into nucleus，resulting in enhancing the defense genes expression. However, the precise role of MORC in regulating plant defense genes expression at the transcriptional level is still unclear. Previously, we identified a transcription factor bZIP18, a novel MORC1-interacting protein. The interaction between MORC1 and bZIP18 was further confirmed by multiple biochemical means. Furthermore, the genetic dissection indicated that bZIP18 negatively regulates plant immunity, which is the first report of bZIP18’s role in plant immunity. This project aims to further analyze the effects of bzip18 mutant on the resistance to different pathogens, and on different signaling pathways, such as PTI and ETI, and clarify bZIP18’s role in plant immunity; the chromatin immunoprecipitation sequence (ChIP-seq) analysis of MORC1 and bZIP18, combined with exploration of their transcriptome data and bZIP18-binding promoter elements, will uncover the defense genes directly regulated by MORC1 and bZIP18; moreover, we will provide insights into the cooperative action of MORC1 and bZIP18, and elucidate the mechanism of fine-tuning plant defense genes expression by MORC1 and bZIP18. Our study will help to understand the molecular mechanism of bZIP18 as a novel regulator in plant immunity and further decipher plant immune signaling network for MORC1.