寄主调控甜菜夜蛾VgR表达的关键驱动因子解析

The phenomenon of host plants affecting insect growth and reproduction has been widely known, but the molecular mechanism of how host plants regulate the reproduction of insects remains still unclear. Vitellogenin receptor (VgR) is the main receptor mediating endocytosis of insect vitellogenin (Vg), which is closely related to insect fecundity. Previous study showed host plants affect the fecundity of Spodoptera exigua by regulating VgR mRNA expression level. In order to analyze the key driving factors of host regulating VgR expression in Spodoptera exigua, this project intends to screen candidate reproductive regulatory genes in S. exigua feeding on different hosts by differential transcriptome sequencing and bioinformatics technology. QPCR technique was used to determine the correlation between key candidate genes and VgR mRNA expression. RNAi studies were conducted on key target genes and through the monitoring of VgR expression before and after the interference of key candidate factors, the potential VgR expression regulation pathway was revealed, and the regulating effect of key factors on VgR expression was clarified. The results of this project can reveal the molecular mechanism of the host regulating the fecundity of S. exigua, and provide the scientific basis for the forecasting and control of S. exigua .

寄主植物影响昆虫生长发育和生殖已获得广泛认知，然而其调控昆虫生殖的内在分子机制仍不明确。卵黄原蛋白受体（VgR）是介导昆虫卵黄原蛋白（Vg）胞吞作用的主要受体，与昆虫生殖力密切相关。前期研究发现寄主植物通过调控甜菜夜蛾VgR的表达来影响其生殖力。为解析寄主植物调控甜菜夜蛾VgR表达的关键驱动因子，本项目通过差异转录组测序和生物信息学筛选不同寄主甜菜夜蛾品系差异表达的候选生殖调控基因，应用qPCR技术明确关键候选基因与VgR表达的相关性；对关键目标基因进行RNAi研究，通过对关键目标基因干扰前后VgR表达的监测，揭示其潜在的VgR表达调控通路，明确关键因子对VgR表达的调控作用。本研究结果可揭示寄主调控甜菜夜蛾VgR表达的分子机制，为甜菜夜蛾准确测报及防控提供科学依据。

卵黄原蛋白受体(VgR)是介导昆虫卵黄原蛋白（Vg）胞吞作用的主要受体，与昆虫生殖力密切相关。项目组前期研究发现甜菜夜蛾取食不同寄主可显著影响其生殖力和VgR表达量。为解析VgR表达量如何受寄主植物影响并调控甜菜夜蛾生殖力，本项目通过差异转录组测序和生物信息学技术筛选到取食不同寄主的甜菜夜蛾品系中与VgR表达相关的JH调控通路以及关键调控基因SeMet1及SeKr-h1。通过PCR技术克隆获得SeMet1及SeKr-h1， SeMet1及SeKr-h1在幼虫-蛹转变期及成虫期高表达，暗示其参与幼虫变态与成虫生殖的功能。通过qPCR技术明确SeMet1及SeKr-h1与寄主适合度的相关性，同时通过RNAi技术研究SeMet1及SeKr-h1的功能，其结果显示下调表达SeMet1及SeKr-h1基因会抑制SeVg/SeVgR以及雌虫卵巢发育进度，进一步明确SeMet1及SeKr-h1在不同寄主影响VgR表达量中的作用。本项目研究结果从VgR调控角度初步揭示寄主调控甜菜夜蛾繁殖力的内在分子机制，为甜菜夜蛾准确测报与防控提供科学依据。