植物水杨酸途径对Q烟粉虱传播TYLCV的影响及分子机制

Plant virus transmission is affected by the complex of insect vector, virus and host plant. Among the three way interactions, plant defense plays an important role in plant virus transmission. It is generally accepted that plant salicylic acid (SA) pathway could be induced by the whitefly, Bemisia tabaci feeding. We hypothesized that the SA pathway could inhibit the virus transmission mediated by B. tabaci Q feeding, which were substantially affected by the whitefly saliva effectors and virus. We firstly determined the effects of SA and TYLCV on feeding behavior and host selecting behavior of B. tabaci Q, and illuminated the effects of SA on virus transmission efficiency through affecting the virus transmission related behaviors. From the point of plant, we investigated the effects of feeding of B. tabaci Q infected TYLCV on expressions of SA-related upstream and downstream genes in tomato plants. Meanwhile from the point of whitefly, we aimed to identify the potential saliva effectors related to SA and TYLCV and verify their feeding functions. Finally, the oxidative phosphorylation (OXPHOS) gene expression may shed some insights on the mechanism of SA and TYLCV on whitefly feeding behavior. The results would help to explicit the effects of plant SA pathway on TYLCV transmission and its behavioral and molecular mechanisms, enriching the interaction theory between whitefly, plant and virus. Further, the research would provide a theoretical basis for the effective management of geminivirus disease transmitted by whitefly.

植物病毒传播受媒介昆虫、病毒和植物三者影响。植物防御反应在三者互作中起重要作用。植物水杨酸（SA）防御途径通常因烟粉虱取食而被诱导，我们推测植物SA途径对烟粉虱传毒行为具有抑制作用，且受烟粉虱唾液效应因子及病毒的影响。本研究首先测定SA和TYLCV对Q烟粉虱取食行为和寄主选择行为的影响，明确SA通过影响Q烟粉虱传毒行为进而影响其传毒效率；然后从植物角度明确携带TYLCV的Q烟粉虱取食对番茄SA途径相关的上下游基因表达的影响，从烟粉虱角度筛选与SA及TYLCV相关的潜在烟粉虱唾液效应因子基因，验证其对Q烟粉虱取食行为的功能；最后从氧化磷酸化基因表达角度（能量代谢）阐释植物SA途径和TYLCV影响烟粉虱取食行为的机制。研究结果将有助于阐明植物SA防御途径对Q烟粉虱传播TYLCV的影响及其行为和分子机制，丰富烟粉虱-植物-病毒互作理论，为烟粉虱传播双生病毒病的有效管理提供理论依据。

植物病毒传播受媒介昆虫、病毒和植物三者影响。植物防御反应在三者互作中起重要作用。植物水杨酸（SA）防御途径通常因烟粉虱取食而被诱导，但是SA对Q烟粉虱与番茄黄化曲叶病毒（TYLCV）行为互作的影响及机制还不清楚。生产上更是缺乏可以有效利用的植物免疫激活剂产品和技术。本研就首先研究外源水杨酸处理对带毒和无毒Q烟粉虱取食行为的影响，进一步明确外源水杨酸处理对带毒Q烟粉虱传毒效率的影响。研究了两种商品化植物免疫激活剂寡糖链蛋白和水杨酸制剂对带毒烟粉虱取食行为的影响及其田间应用效果。还监测了本地烟粉虱隐种和TYLCV病毒携带情况，并进行了烟粉虱携带病毒组学研究。最后进行了带毒和无毒烟粉虱取食JA/SA处理番茄苗后上下游基因表达研究。. 结果表明，带毒烟粉虱在清水对照处理番茄上的韧皮部吸食时间显著长于水杨酸处理的带毒和无毒烟粉虱。外源喷施水杨酸处理的TYLCV病毒含量显著低于对照组，病毒相对含量分别为2.25和27.95。寡糖链蛋白处理后韧皮部取食时间较对照组缩短50%。移栽后35天，施用免疫激活剂寡糖链蛋白水杨酸制剂病情指数最低。对天津4个地区、12个种群烟粉虱监测表明，MED隐种占比93.33%。病毒组数据则显示这些烟粉虱田间种群中包含3种菜豆金色花叶病毒属病毒和1种毛形病毒属病毒。带毒及无毒烟粉虱取食外源喷施JA、SA番茄苗后的转录组数据及基因功能注释结果显示，无毒组的共有上调差异表达基因主要涉及到物质运输过程，带毒组的共有上调差异表达基因主要涉及到转录调控、解毒过程。带毒组处理组的9个共有上调差异表达基因中，解毒酶基因Sulfotransferase1和重要细胞调控基因MAPK3基因分别上调9.4倍（JA）和1.7倍（SA）。. 研究结果将有助于阐明植物SA防御途径对Q烟粉虱传播TYLCV的影响及其行为和分子机制，为烟粉虱传播双生病毒病的有效管理提供理论依据。