基于泛基因组学探索烟粉虱入侵扩散的分子遗传基础

Exotic invasive whitefly Bemisia tabaci Q and B are the dominant species in field in China, while non-invasive indigenous species generally have no harm of agricultural production with weak reproduction competition ability and narrow distribution. Previous reports have shown that asymmetric mating interactions and insecticides-induced displacement are two most important ecological mechanism for the competitive displacement of indigenous species by B whitefly, and B by Q whitefly, respectively. The proposed research is to clarify the molecular and genetic basis of the invasiveness of whitefly B. tabaci with pan-genome and comparative genome methods. This foundation aim to obtain invasive B and other indigenous species genome sequences based on Q whitefly genome, screen out core genes, shared and specific genes of this species, construct a phylogenetic tree of these B.tabaci species at genome level, clarify the key genome areas and key genes linked with its invasiveness ability by comparative genome method like positive selection, gene family expansion/contraction and so on, and further validate these sequences. The results of this study are of great theoretical and practical significance for clarifying molecular and genetic mechanisms of widespread invasiveness of B. tabaci and further controlling whitefly and other exotic invasive species.

外来入侵Q和B烟粉虱是当前我国田间主要危害种，而非入侵土著烟粉虱繁殖、竞争能力较弱且分布范围狭窄一般难以构成农业生产危害。先前发现非对称交配互作和杀虫剂驱动是烟粉虱成功入侵的关键生态机制，但生态机制背后的分子机制即烟粉虱成功入侵的分子遗传基础仍不甚清楚。本项目拟在前期Q烟粉虱基因组研究的基础上，通过获取入侵种和非入侵种烟粉虱基因组序列，利用比较基因组学和泛基因组方法，筛选获得烟粉虱核心/特异性/非必须基因组基因，构建烟粉虱基因组水平系统进化树；通过正选择、基因家族扩张收缩、特异基因获得丢失等锁定烟粉虱入侵性潜在关联区域和关键基因；验证候选关键基因组区域和关键基因。研究结果对于揭示烟粉虱入侵扩散的分子遗传基础及控制烟粉虱的持续扩散危害具有重大理论及实际意义。

外来入侵Q和B烟粉虱是当前我国田间主要危害种，而非入侵土著烟粉虱繁殖、竞争能力较弱且分布范围狭窄一般难以构成农业生产危害。先前发现非对称交配互作和杀虫剂驱动是烟粉虱成功入侵的关键生态机制，但生态机制背后的分子机制即烟粉虱成功入侵的分子遗传基础仍不甚清楚。为明确烟粉虱入侵扩散的分子遗传基础，或者说其中最重要的杀虫剂驱动主导的 Q 烟粉虱替代 B 烟粉虱的分子机制及调控网络，本项目首先揭示了 MED/Q 烟粉虱以及4 种本地种烟粉虱基因组的遗传密码；接着通过B、Q烟粉虱之间以及入侵种和本地种烟粉虱基因组之间的比较分析，发现B、Q烟粉虱乙酰胆碱受体序列相似度极高，故而排除受体突变导致B、Q烟粉虱药剂敏感性差异；通过代谢酶系基因的序列分析，明确代谢酶系对B、Q烟粉虱药剂敏感性差异有主要作用，但对入侵种和本地种烟粉虱之间入侵能力差异贡献作用有限；进一步通过基因家族扩张收缩分析以及通过 Pd 参数比较去挖掘粉虱入侵性的遗传基础，最终发现烟粉虱气味受体之间的差异可能是烟粉虱入侵扩散的关键遗传分子差异。研究结果对于揭示烟粉虱入侵扩散的分子遗传基础及控制烟粉虱的持续扩散危害具有重大理论及实际意义。