B和Q型烟粉虱传播瓜类褪绿黄化病毒机理研究

Research on virus transmission mechanisms of piercing-sucking insects is essential for elucidation of key steps during the process of virus transmission and thereby facilitating development of effective control strategies for plant virus diseases. Cucurbit chlorotic yellows virus (CCYV), is a newly found virus occurring in cucurbit crops and and some other plants. There have been no reports on transmission mechanisms yet. The virus is specifically transmitted by Bemisia tabaci B and Q biotypes in a semipersistent manner. Previous studies found that there are significantly different transmission abilities between B and Q biotypes of B. tabaci. In the present proposal, based on our previous research results, mechanisms of CCYV transmission in the two biotypes that differ in transmission ability will be studied in the following aspects: basic transmission features, virus binding sites in the vector, vector binding protein characteristics, and vector-virus interactions including influences of CCYV on insect behaviors and plant features and protein interactions, by using techniques and methods in insect behavior, molecular biology, electrical penetration graphs, immunology, and fluorensence microscope and confocal laser scanning microscope. This project will extend our understanding of semipersistent virus transmission mechanisms by piercing-sucking insects and provide a theoretical basis for searching for new targets and new strategies in disease control of plant viruses transmitted by different biotypes of Bemisia tabaci.

刺吸式昆虫传播植物病毒机理的研究，有助于阐明介体传毒的关键环节从而有效控制作物病毒病。瓜类褪绿黄化病毒（Cucurbit chlorotic yellows virus, CCYV）是近几年报道的一种新病毒，在瓜类上严重发生，但介体传毒机理的研究尚未见系统报道。该病毒由烟粉虱Bemisia tabaci B型和Q型生物型半持久性特异传播，我们初步研究发现两种生物型传毒能力有较大差异。在前期研究的基础上，本项目利用昆虫行为学、分子生物学、刺吸电位、免疫学、荧光显微镜和激光共聚焦显微镜等技术和方法，试图从介体传毒特性、病毒在介体内的滞留位点、结合蛋白特性、植物-介体-病毒互作（病毒对昆虫行为和植物特性的影响、病毒-介体蛋白互作）等方面，研究烟粉虱传播CCYV的规律，比较分析烟粉虱两种生物型传毒能力差异的机理，以期为针对烟粉虱不同生物型传播病毒寻找新的防治靶标和制定控制策略奠定理论基础。

瓜类褪绿黄化病毒（Cucurbit chlorotic yellows virus, CCYV）是近几年报道的一种新病毒，在瓜类上严重发生，但介体传毒机理的研究尚未见系统报道。本项目以CCYV及其介体B型和Q型烟粉虱Bemisia tabaci为材料，利用昆虫行为学、分子生物学、刺吸电位、免疫学、荧光显微镜和激光共聚焦显微镜等技术和方法，从介体传毒特性、病毒在介体内的滞留位点、结合蛋白特性、植物-介体-病毒互作（病毒对昆虫行为和植物特性的影响、病毒-介体蛋白互作）等方面，研究烟粉虱传播CCYV的规律，比较分析烟粉虱两种生物型传毒能力差异的机理，取得如下研究成果:（1）建立了昆虫传毒研究的研究体系，包括植物病毒体系保持技术，灵敏的检测技术和膜饲喂技术；（2）通过传毒特性和介体内结合位点定位，确定了烟粉虱传播CCYV病毒的半持久性质，病毒在介体内的结合位点是前肠；（3）比较了B和Q型烟粉虱传播CCYV病毒能力的差异，分析了其造成传毒效率差异的原因是获毒能力影响带毒量，也与寄主适应能力密切相关；（4）进行了CCYV-烟粉虱-寄主植物互作研究，分别阐明了CCYV对介体烟粉虱寄主趋性、取食行为和体内相关酶系的影响，及对寄主植物JA防御相关基因和挥发性化学物质的影响等。（5）发表论文7篇，其中SCI论文2篇；出版专著一部。（6）培养2名博士生（其中一名已经毕业），6名硕士生，2名青年教师。本项目取得的研究成果有利于拓展对于刺吸式昆虫传播半持久性病毒机理的认识，为针对烟粉虱不同生物型传播病毒寻找新的防治靶标和制定控制策略奠定了理论基础。