基于性信息素的小菜蛾交配选择对寄主植物的响应机制

Insect sex pheromones play an indispensible role in chemical communication.The traditional paradigm was that their main purpose in sexual behaviour was to coordinate mate and species recognition and thus pheromones were conserved in structure and function.In recent years,however,there has been increasing evidence that that there are individual differences in male and female insect mate attraction and assessment behaviors, which determine the canalization and evolutionary costs of particular mate-choice decisions.In addition, there has been increasing evidence of significant interactions between host plants and insect sex pheromones , which could result in more complex situation in mate choice. However, the mate assessment in mate choice and the response mechanism to host plants have been heretofore largely ignored. In this project, we will use the diamondback moth, Plutella xylostella (DBM), a major destructive pest of brassica crops ,to investigate: (1)Female signals and male response of adults developed from larvae rearing on three different varieties of cruciferous plants for more than 5 generations, and also prolonged pre-exposure of male and female DBM to the volatiles from these cruciferous plant varieties;(2) Expression of genes concerned with pheromone biosynthesis and olfaction, including Plx-PBAN, Plx-PBANr, PxylPBP1, PxPBP, PxylGOBPl，PxylGOBP2，PlxyOr83b; and(3) Mate assessment cost using an indexes involving factors related to DBM biology, endocrine interruption, and sex pheromone synergism. Our research will clarify the role of host plants in regulating the sex pheromone-based mate choice occurring in DBM adults. In addition, this work will add to our understanding of the function of insect sex pheromones in the context of host-plant variance, allowing plant protection experts to make better-informed decisions concerning which potential methods to choose in order to control this devastating insect pest.

性信息素是昆虫化学通讯系统的核心问题，传统研究认为其功能是保守的。但近年有证据表明，基于性信息素的交配选择应包括交配评估，尤其要体现个体差异和选择代价。由于寄主植物与昆虫性信息素相互作用普遍存在，在寄主植物存在模式下，交配选择将表现更加复杂。但是，以往研究往往忽略交配选择中的这些重要特征，同时未阐明交配选择对寄主植物的响应机制。因此本项目以小菜蛾为对象，（1）在幼虫取食、成虫暴露的两种寄主模式下，测定成虫交配选择的性信号特征，确定典型寄主模式；（2）测定典型寄主模式下小菜蛾性信息合成和嗅觉相关基因的表达动态，明确表现性信号的分子机理；（3）测定交配选择后代生长发育和生殖力指标，分析性信息素相关的内分泌干扰效应以及植物挥发性物质的增效作用，明确交配选择代价；从而阐明基于性信息素的小菜蛾交配选择对寄主植物的响应机制。研究结果对于全面评价昆虫信息素功能，提出害虫控制新措施等都具有重要科学意义

性信息素是昆虫化学通讯系统的核心问题，基于性信息素的害虫诱捕、迷向、监测技术对于有效控制害虫起到重要作用。本研究针对十字花科蔬菜重要害虫小菜蛾（Plutella xylostella），开展基于性信息素的小菜蛾交配选择对寄主植物的响应机制的研究。（1）系统研究了暴露于寄主挥发性物质模式下小菜蛾交配选择的性信号特征，明确了光周期对小菜蛾羽化节律的影响、不同营养源对小菜蛾成虫的嗅觉行为、触角电位反应和繁殖力的影响以及植物挥发物对小菜蛾性信息素合成、触角电位和嗅觉行为反应和交配节律的影响。（2）测定了典型模式下小菜蛾性信息素合成及嗅觉相关基因的表达，明确植物挥发物对小菜蛾PBAN基因表达量的影响，阐明小菜蛾表现极端交配选择性信号的分子机理。（3）探讨了典型模式下小菜蛾交配选择代价，明确了小菜蛾保幼激素相关基因的表达动态及外源调节因子（饥饿、短时高温、蚊蝇醚和OTFP）对保幼激素相关基因表达的影响。本项目系统解析了基于性信息素的小菜蛾交配选择对寄主植物的响应机制，研究结果对于全面评价昆虫信息素功能，提出害虫控制新措施等都具有重要科学意义。项目执行期间发表论文6篇，其中SCI学术论文3篇，获市科学技术进步奖二等奖1项，福建省农业科学院科学技术奖一等奖1项；授权专利9项，其中发明专利5项，实用新型专利4项。