植物次生物质I3C通过蜕皮激素信号途径调控斜纹夜蛾解毒酶表达的机理研究

杂食性昆虫的庞大和复杂的解毒酶系统使其能很好地适应多种宿主植物，这为以解毒酶为直接靶标开展害虫防治带来困难。另一方面，对调控解毒酶表达的关键转录因子和miRNA的研究有可能为害虫防治提供新的思路和途径。我们发现植物次生物质吲哚-3-甲醇（I3C）可诱导斜纹夜蛾蜕皮激素（20E）生成途径关键基因、20E受体及解毒酶表达，推测I3C可能通过调节20E途径而引起解毒酶的表达，从而导致斜纹夜蛾对毒性I3C的抗性。项目将从4个方面开展研究以证明这个推测：1）I3C对蜕皮激素的诱导作用及其机制；2） I3C诱导的20E信号途径与解毒酶表达的相关性；3）I3C诱导20E通路转录因子对解毒酶表达调控的分子机理；4）作用于调控解毒酶的关键转录因子的miRNA。研究将明确I3C通过20E信号途径促进解毒酶表达的机理， 为阐明多食性斜纹夜蛾适应不同宿主植物的分子机理提供证据，为害虫防治提供新的分子靶标，有着重要的理论和应用意义。

Generalists can adapt very well a wide range of host plants by its large and complicated detoxifying enzyme system, which makes it difficult to control insect pests by directly targeting detoxifying enzymes. On other hand, the study of transcription factors and miRNA that are involved in the control of detoxifying enzymes may provide a novel approach toward efficient pest controlling. We found that the plant secondary substrate，indole - 3 - methanol ( I3C ), can activate the genes involving in the generation of 20-hydrooxyecdysone (20E) and the expression of detoxifying enzymes of Spodoptera litura, suggesting the I3C may induce detoxifying enzyme expression by the 20E pathway. To demonstrate this hypothesis, this project will study 1) Titer and induction mechanism of 20E by I3C; 2) The relationship between detoxification enzyme and 20E induced by I3C; 3) Regulation of detoxifying enzymes by I3C-induced transcription factors in the 20E pathway; 4) miRNA of transcription factors targeting detoxifying enzymes. The study will clarify the mechanism of I3C induction of detoxifying enzymes by the 20E pathway, providing the evidence for molecular mechanism in the adaption of generalist S. litura to different host plants, and potential molecular targets for insect pest controlling.