斜纹夜蛾应对植物次生物质的关键因子Nrf2和Ap-1的表观遗传调控机制研究

宿主植物通常以次生物质毒性来防御昆虫的取食，而植食性昆虫以其解毒酶和抗氧胁迫酶系统对抗植物次生物质来适应宿主植物。因此，研究昆虫如何应对植物次生物质毒性的调控途径及其机制具有重要的理论和应用意义。我们前期研究发现，斜纹夜蛾的抗氧胁迫因子Nrf2和Ap-1在应对宿主植物次生物质时受表观遗传调控，进而启动防御系统，降解植物次生物质和清除活性氧。在此基础上，本项目拟以农业害虫斜纹夜蛾为研究对象，开展下列2个方面内容的研究：（1）Nrf2翻译的表观遗传调控机制；（2）Ap-1调控组蛋白去甲基化酶LSD1翻译的表观遗传调控机制。通过研究将明确斜纹夜蛾应对植物次生物质过程中RNA甲基化和miRNA两者协调调控Nrf2翻译的机制、Ap-1通过抑制LSD1翻译而促进抗植物次生物质基因表达的机制。项目为阐明植食性害虫适应宿主植物的表观遗传调控机制，为害虫防治提供新的理论基础和指导。

Host plants often defense insect damaging by generating toxic phytochemicals, whereas phytophagous insects use their detoxification and antioxidant enzyme systems to defense the phytochemical toxicity and adapt their host plants. Therefore, the study on the regulation pathways and their regulatory mechanisms of detoxification will be greatly helpful in both basic theory and application for pest controlling. In our previous studies, we found that the epigenetic regulation enhanced the expression of antioxidative factors Nrf2 and Ap-1 in adaption of Spodoptera litura to phytochemicals, activating the defensing systems to detoxify phytochemicals and scavenge reactive oxygen species. In this proposal, we will focus on S. litura and study 1) the epigenetic regulatory mechanism of Nrf2 expression at the post transcriptional level; 2) the epigenetic regulatory mechanism of AP-1 in regulation of the histone demethylase LSD1 translation. The study will clarify the epigenetic regulatory mechanisms of the Nrf2 translation by cooperation of RNA methylation and miRNAs, and the mechanism of phytotochemical tolerance gene expression through AP-1-inhibited LSD1 translation. We hope that these studies will benefit the elucidation of the epigenetic regulatory mechanism of the adaptation of the phytophagous pests to host phytochemicals, serving as a theory base and providing potential novel strategies for pest controlling.