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

PLoS Pathogens

Said A. Ghabrial¹  Tao Chen²  Songsong Wu²  Daohong Jiang²  Jiatao Xie²  Jiasen Cheng²  Yanping Fu² 

[1] Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America;State Key Laboratory of Agricultural Microbiology, The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China

关键词: Mycelium;    Fungi;    Infectious disease control;    Fungal genetics;    Plant fungal pathogens;    Parasitic diseases;    Viral transmission;    infection;    Fungal diseases;   

DOI  :  10.1371/journal.ppat.1006234

学科分类：生物科学（综合）

来源: Public Library of Science

【 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.

【 授权许可】

CC BY