PLoS Pathogens:华中农大谢甲涛课题组发表抗病毒天然免疫研究论文

摘要 : 2017年3月23日，国际微生物学知名期刊《PLOS Pathogens》在线发表了华中农业大学姜道宏教授领衔的研究团队在真菌病毒及其生物防治领域取得的新进展

2017年3月23日，国际微生物学知名期刊《PLOS Pathogens》在线发表了华中农业大学姜道宏教授领衔的研究团队在真菌病毒及其生物防治领域取得的新进展“Virus-mediated suppression of host non-self recognition facilitates horizontal transmission of heterologous viruses”，研究被主编选为“Featured Research”论文发表在杂志网站首页，并以题为“Novel virus breaks barriers between incompatible fungi”的评论文章。论文的第一作者为博士生吴松松，通讯作者为我校谢甲涛教授。

利用低毒相关病毒防治作物真菌病害是一种潜在生物防治策略，在植物病害物防治方面具有重要的应用价值。真菌病毒传播途径主要依赖寄主个体间菌丝融合进行传播，而病原真菌个体间复杂的营养体不亲和型(Vegetative incompatibility, VIC)制限制了病毒在病原真菌群体内的扩散、传播，最终影响到毒力衰退相关病毒的控病效果。因此，如何克服真菌营养体不亲和性反应是利用真菌病毒成功控制作物病害重要的科学问题。

研究人员发现低毒相关真菌呼肠孤病毒SsMYRV4可抑制寄主核盘菌G蛋白基因、多数营养体亲和性相关基因的表达，进而降低寄主由于程序性细胞死亡反应而引发的不亲和反应。细胞染色、显微观察均证实携带SsMYRV4的菌株能够与其它隶属于不同营养体亲和群的个体发生菌丝融合。与其它低毒相关病毒(如SsDRV、SsMV1等)共侵染同一核盘菌菌株时，SsMYRV4促进其它低毒相关病毒在不同VIC个体间传播。SsMYRV4及其寄主可以作为弱毒相关病毒的传播“桥梁”，促进病毒在核盘菌群体中的有效传播。此外，病毒介导的低毒菌株多数表现出营养生长缺陷、野外存活能力较差的特性，该特性也是限制真菌病毒实践应用的缺陷之一，但SsMYRV4可以增强寄主对环境的适应能力(如增加耐高渗能力和耐活性氧的能力等)。因此，SsMYRV4这种削弱寄主不亲和性反应的特性，为其他具有生防潜力、但受限于菌丝营养体不亲和性限制的病毒的应用提供了一种新策略，同时也增强了人们对病毒生态及进化的认识。

原文链接：

virus-mediated suppression of host non-self recognition facilitates horizontal transmission of heterologous viruses

原文摘要：

Non-self recognition is a common phenomenon among organisms; it often leads to innate immunity to prevent the invasion of parasites and maintain the genetic polymorphism of organisms. Fungal vegetative incompatibility is a type of non-self recognition which often induces programmed cell death (PCD) and restricts the spread of molecular parasites. It is not clearly known whether virus infection could attenuate non-self recognition among host individuals to facilitate its spread. Here, we report that a hypovirulence-associated mycoreovirus, named Sclerotinia sclerotiorum mycoreovirus 4 (SsMYRV4), could suppress host non-self recognition and facilitate horizontal transmission of heterologous viruses. We found that cell death in intermingled colony regions between SsMYRV4-infected Sclerotinia sclerotiorum strain and other tested vegetatively incompatible strains was markedly reduced and inhibition barrage lines were not clearly observed. Vegetative incompatibility, which involves Heterotrimeric guanine nucleotide-binding proteins (G proteins) signaling pathway, is controlled by specific loci termed het (heterokaryon incompatibility) loci. Reactive oxygen species (ROS) plays a key role in vegetative incompatibility-mediated PCD. The expression of G protein subunit genes, het genes, and ROS-related genes were significantly down-regulated, and cellular production of ROS was suppressed in the presence of SsMYRV4. Furthermore, SsMYRV4-infected strain could easily accept other viruses through hyphal contact and these viruses could be efficiently transmitted from SsMYRV4-infected strain to other vegetatively incompatible individuals. Thus, we concluded that SsMYRV4 is capable of suppressing host non-self recognition and facilitating heterologous viruses transmission among host individuals. These findings may enhance our understanding of virus ecology, and provide a potential strategy to utilize hypovirulence-associated mycoviruses to control fungal diseases.

doi:10.1371/journal.ppat.1006234

作者：谢甲涛

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