PNAS:浙江大学王晓伟教授课题组揭示植物病毒的秘密传播通道

摘要 : 2017年6月7日,国际著名学术期刊《美国科学院院刊》在线发表了浙江大学昆虫科学研究所王晓伟教授课题组题为“Vector development and vitellogenin determine the transovarial transmission of begomoviruses”的研究论文

2017年6月7日,国际著名学术期刊《美国科学院院刊》在线发表了浙江大学昆虫科学研究所王晓伟教授课题组题为“Vector development and vitellogenin determine the transovarial transmission of begomoviruses”的研究论文,研究报道了历时5年潜心研究发现的植物病毒传播的一个重要通道。昆虫所博士研究生卫静和何亚洲为文章的共同第一作者,王晓伟教授为通讯作者。

在目前已知的近千种植物病毒中,约三分之二的病毒主要依赖媒介昆虫进行传播,因此研究植物病毒通过媒介昆虫传播的机制具有重要意义。双生病毒占目前已记录的全部植物病毒三分之一,主要通过媒介昆虫烟粉虱传播。之前的研究普遍认为,双生病毒只能由其媒介昆虫烟粉虱在带毒的植物上取食时获取,然后迁移或扩散到健康植物上取食时将病毒传给后者,而不能通过卵传给烟粉虱的后代。王晓伟教授课题组研究发现,一种近30年入侵到世界50多个国家、对农业生产造成重大危害的双生病毒即番茄黄曲叶病毒(TYLCV)可以高效侵染烟粉虱的生殖系统并由烟粉虱通过产卵将该病毒传播到其后代,这些后代在病毒的非寄主植物上发育到成虫后,可以迁移到新的寄主植物上传播病毒,使后者感染病毒发病。他们研究发现,TYLCV在媒介昆虫烟粉虱中经产卵传播的效率是与烟粉虱成虫的发育阶段密切相关的,只有已怀有大量成熟卵子的成虫才能通过这个途径高效传播,其分子机制是TYLCV病毒粒子可以与烟粉虱的卵黄原蛋白互作,在后者的配合下侵染烟粉虱的卵母细胞,从而进入卵中。室内接种和田间试验表明,TYLCV可以在没有病毒寄主植物存在的条件下,在烟粉虱体内至少维持两代,即40-50天,然后这些带毒的媒介昆虫仍可将病毒传给新的寄主植物,使后者患病。TYLCV这一传播通道,显著增强了其传播和扩散的效率,可能是TYLCV近30年来在全球快速入侵并造成严重危害的重要机制之一,这将促使目前全球各国改进有关烟粉虱和双生病毒的检疫方法。同时,这一发现对有效防控TYLCV等病毒的发生蔓延提供了新的重要基础信息,提示以往广泛推行的在作物地周围铲除病毒寄主植物、阻断其传播的方法在很多生境中是无效或低效的,可能需要对防控策略和方法做重大改进。最后,该研究首次发现植物病毒是否经卵传播与介体昆虫的发育阶段有着密切关系,为研究其他病毒经卵传播的特性提供了新的视角。

原文链接:

Vector development and vitellogenin determine the transovarial transmission of begomoviruses

原文摘要:

The majority of plant viruses are transmitted by insect vectors between hosts, and transovarial transmission of viruses from vector parents to offspring has great significance to their epidemiology. Begomoviruses are transmitted by the whitefly Bemisia tabaci in a circulative manner and are maintained through a plant–insect–plant cycle. Other routes of begomovirus transmission are not clearly known. Here, we report that transovarial transmission from female whiteflies to offspring often happens for one begomovirus, Tomato yellow leaf curl virus (TYLCV), and may have contributed significantly to its global spread. We found that TYLCV entry of the reproductive organ of its vector mainly depended on the developmental stage of the whitefly ovary, and the transovarial transmission of TYLCV to offspring increased with whitefly adult age. The specific interaction between virus coat protein (CP) and whitefly vitellogenin (Vg) was vital for virus entry into whitefly ovary. When knocking down the expression of Vg, the entry of TYLCV into ovary was inhibited and the transovarial transmission efficiency decreased. In contrast, another begomovirus, Papaya leaf curl China virus (PaLCuCNV), CP did not interact with whitefly Vg, and PaLCuCNV could not be transovarially transmitted by whiteflies. We further showed that TYLCV could be maintained for at least two generations in the absence of virus-infected plants, and the adult progenies were able to infect healthy plants in both the laboratory and field. This study reports the transovarial transmission mechanism of begomoviruses, and it may help to explain the evolution and global spread of some begomoviruses.

doi:10.1073/pnas.1701720114

作者:王晓伟

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