Q烟粉虱水平转移基因BtWRS补偿原生共生菌持家基因丢失机制

原生共生菌对昆虫的生命生殖活动起重要作用，阐明二者共生关系对害虫防治有重要意义。烟粉虱是重大入侵害虫，其高效绿色防控是世界性难题。申请人前期研究表明，Q烟粉虱原生共生菌持家基因WRS丢失对共生菌功能并无显著影响。进一步于Q烟粉虱基因组中发现了一个源自于细菌的水平转移基因BtWRS，且其表达模式变化与Q烟粉虱原生共生菌丰度变化呈正相关。据此推测，BtWRS补偿了Q烟粉虱原生共生菌持家基因WRS的功能。本研究首先对BtWRS的水平转移特征进行验证；再利用大肠杆菌重组工程菌为模型，明确其持家基因功能；进一步解析BtWRS维持Q烟粉虱原生共生菌存活与代谢的分子机制；最终阐明BtWRS对Q烟粉虱-原生共生菌系统的保障作用。研究结果将阐明Q烟粉虱水平转移基因补偿其原生共生菌持家基因丢失的分子机制，丰富昆虫-共生菌共生理论，为突破以共生菌为靶标的烟粉虱绿色防控技术瓶颈提供新思路和新途径。

Primary symbiont plays an important role on the development and reproduction of insects. Elucidating the relationship between host insect and primary symbiont has significant efforts on pest management. Bemisia tabaci is an important invasive pests of agriculture in the world. The B. tabaci management with high efficiency and safety is a worldwide challenge. The applicant's previous study found that housekeeping gene WRS lost of primary symbiont of B. tabaci Q does not had significant efforts on itself. Further, a bacterial WRS originated horizontally transferred gene (BtWRS) were identified in B. tabaci Q. The expressional pattern of BtWRS among different stages was positively correlated with changes of primary symbiont content. Therefore, applicant speculated that BtWRS compensates for the lossing housekeeping gene of the primary symbiont. In this study, the horizontal transfer gene events of BtWRS was firstly verified. Then the by using a genetic engineering strain of Escherichia coli as model, housekeeping function of BtWRS was clarified. Further, the molecular mechanism of BtWRS to maintain the survival and metabolism of Portiera was analyzed. Finally, the supportive role of BtWRS on B. tabaci Q-endosymbiosis system was clarified. The research would elucidate mechanism that insects’ horizontal gene transfer compensate for housekeeping genes lost of primary symbionts, enrich the insect-endosymbiont symbiotic theory as well as provide new ideas and new ways for breaking through the bottleneck of green control technology that B. tabaci was targeted by endosymbiosis.