甜菜夜蛾和斜纹夜蛾间性信息素感受的相互影响及其机制

The insect sex pheromones have the characteristics of species-specificity and high sensitivity because of the specific proportion of multicomponent in moth communication system. Therefore, many of lepidopteran sex pheromones can be utilized in integrated pest management because they are nontoxic to mammals and environmental friendly. Previous research always target in single pest, but many crops are often damaged by overlapping pests which share some pheromone components. In addition, preliminary study indicated some insect can recognize pheromone component of other species. Our project takes Spodoptera exigua and S. litura, both of which are serious pests on several plants, as the research objects, aiming to clarify the pheromonal interaction and its mechanisms with respect to sympatric and simultaneously insect species. In order to confirm the interaction and dose effect of pheromone components, the electrophysiological and behavioral measurement on the two species’ sex pheromone would be first conducted. Further study will focus on characteristic response of pheromone binding protein (PBP) and pheromone receptor (PR) to sex pheromone components of one pest to another, with the expect of exploring the mechanism of the interaction on pheromone communication system. The expected results in this research can not only help to better understand the species-specific of communication system on moths, but also provide a theoretical basis of multispecies management by using insect sex pheromone.

蛾类昆虫性信息素的微量、多组分及特定比例等特点，赋予两性间化学通讯极高的灵敏性和种特异性，可开发应用于害虫的种群监测及绿色防治。但以往研究多以单一害虫为靶标，而农作物一般为多种害虫同时发生危害，且不同害虫常使用部分相同性信息素组分；研究还发现，一种害虫可以识别其他害虫的性信息素组分。本项目以混合发生的蔬菜害虫甜菜夜蛾和斜纹夜蛾为对象，利用电生理学及行为学技术测定两种害虫性信息素组分在诱蛾活性方面的相互影响及其剂量效应，以期阐明两种害虫性信息素通讯间的相互影响；同时利用体外表达及功能分析技术，系统研究信息素结合蛋白（PBP）及受体（PR）在两种害虫性信息素组分间的互作反应特性，探讨性信息素感受在种间相互影响的分子机制。研究结果不仅可以更深入揭示蛾类昆虫性信息素通讯系统的种特异性，而且为开发以多害虫同时发生为靶标的性信息素协同防治技术提供重要指导。

蛾类昆虫性信息素的微量、多组分及特定比例等特点，赋予两性间化学通讯极高的灵敏性和种特异性，可开发应用于害虫的种群监测及绿色防治。斜纹夜蛾（Spodoptera litura）和甜菜夜蛾（S. exigua）属于多种作物的同域害虫，二者的性信息素均为多元组分，其中包含一个共有组分Z9,E12-14:OAc，以及3种特有组分Z9-14:OH（S. exigua）、Z11-16:OAc（S. exigua）和Z9,E11-14:OAc（S. litura）。以往的研究表明这两种昆虫很好的被自身的性信息素所吸引，但是能否感受它种昆虫的性信息素还未知。本研究首先利用触角电位技术分别测定了斜纹夜蛾雄蛾对甜菜夜蛾特有组分Z9-14:OH和Z11-16:OAc，以及甜菜夜蛾雄蛾对斜纹夜蛾特有组分Z9,E11-14:OAc的触角电位反应，结果表明两种夜蛾均对它种信息素特有组分有显著的电位反应。田间诱捕实验显示，Z9-14:OH和Z11-16:OAc可以显著抑制斜纹夜蛾雌蛾性信息素对雄蛾的吸引，而Z9,E11-14:OAc在高剂量时可以显著影响甜菜夜蛾雌蛾性信息素对雄蛾的吸引。通过体外表达两种害虫的信息素结合蛋白（PBP）基因和荧光竞争性结合实验，结果显示SlitPBP1和SlitPBP2分别与Z9-14:OH均有较强的结合能力（Ki：2.01, 1.36），SexiPBP1和SexiPBP2分别与Z9,E11-14:OAc也有较强的结合能力（Ki：1.15, 3.24）。以上结果表明，两个同属害虫斜纹夜蛾和甜菜夜蛾不仅可以感受同种的性信息素组分，而且可以识别它种性信息素组分，以进一步增强二者之间的生殖隔离。该研究结果不仅深入揭示了同域同属昆虫生殖隔离的新机制，以及蛾类昆虫性信息素通讯系统的种特异性，而且为开发以多害虫为靶标的性信息素协同防治技术提供理论依据。