灰飞虱毒死蜱抗性和高温适应性的协同进化机制研究

Insecticides and temperature stress are main factors affected insect genetic structure. It is very important to study the interactive mechanisms of insecticides resistance and high temperature adaptation for clearing mechanisms of insect to environment stress, founding reasonable strategy to control pest and exploring new target of insecticides. This project is based on the previous study of chlorpyrifos resistance increased adaptation to high temperature, and high temperature resistance decreased the sensitivity of Laodelphax striatellus to chlorpyrifos. It will use transcriptome sequencing and gene expression microarray techniques to screen out the genes responded to chlorpyrifos resistance and high temperature adaptation. The key genes and pathway responded to both stress factors will be highlighted by Blast2go and other bioinformatics tool. Then these key genes function will be studied by RNAi, and the expression by qPCR and Western blot. The results will clear the role of key genes in coevolutionary between insecticides resistance and temperature adaptation and light the adaptation molecular mechanisms of the small brown planthopper to environment.

杀虫剂和温度胁迫是影响害虫种群遗传结构的两个主要外源因素。研究杀虫剂抗性和高温适应性的互作机制对阐明害虫环境适应性机理，制定科学合理的综合防治措施，发掘农药新靶标具有重要意义。本项目以重要水稻害虫灰飞虱为研究对象，在发现毒死蜱抗性提高灰飞虱高温适应性和耐高温品系对毒死蜱敏感性下降的基础上，利用转录组测序和表达谱芯片技术筛选毒死蜱抗性和高温适应性共响应基因；再采用Blast2go等生物信息学软件预测共响应基因的功能和生物学路径，确定目标基因；然后利用RNAi、Western Blot等分子生物学技术研究目标基因的功能和时空表达特性；明确目标基因在毒死蜱抗性和高温适应性协同进化中的作用，阐明灰飞虱环境适应性进化机制。

本项目主要研究灰飞虱毒死蜱抗性和高温适应性的协同进化机制。生物测定和生命表比较发现毒死蜱抗性灰飞虱对高温的适应性增加，而耐高温的灰飞虱对毒死蜱的敏感性下降。转录组分析发现抗性灰飞虱热激蛋白基因的过量表达可能是其高温适应性提高的原因。分子生物学研究进一步证实热激蛋白在灰飞虱抗逆性适应中起重要作用，而且针对不同的胁迫因子，由不同的热激蛋白组合应激。这些研究结果表明温度适应性和杀虫剂抗性间存在明显的相互作用，因此在制作灰飞虱发生预测模型或者制定灰飞虱综合防控策略时，尤其是水稻生长晚期的防治措施时，应充分考虑当年夏季温度、害虫的抗性水平等因素。