1. Nine viruses from eight lineages exhibiting new evolutionary modes that co-infect a hypovirulent phytopathogenic fungus
- Author
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Shufen Cheng, Yanping Fu, Fan Mu, Jichun Jia, Jiatao Xie, Jiasen Cheng, Bo Li, Tao Chen, Daohong Jiang, and Yang Lin
- Subjects
RNA viruses ,Genome ,Biochemistry ,Fungal Evolution ,Biology (General) ,Phylogeny ,Genomic organization ,Data Management ,Viral Genomics ,Sclerotinia sclerotiorum ,Phylogenetic Analysis ,Genomics ,Biological Evolution ,Enzymes ,Phylogenetics ,Viral evolution ,Horizontal gene transfer ,Viruses ,Helicases ,RNA, Viral ,Research Article ,Computer and Information Sciences ,QH301-705.5 ,Gene prediction ,Immunology ,Mycology ,Microbial Genomics ,Genome, Viral ,Biology ,Fungal Viruses ,Microbiology ,Virus ,Viral Evolution ,Ascomycota ,Virology ,Genetics ,Fungal Genetics ,Evolutionary Systematics ,Cell Lineage ,Gene Prediction ,Molecular Biology ,Fungal Genomics ,Taxonomy ,Plant Diseases ,Evolutionary Biology ,Brassica napus ,Organisms ,Biology and Life Sciences ,Computational Biology ,Proteins ,RC581-607 ,biology.organism_classification ,Genome Analysis ,Organismal Evolution ,Plant Leaves ,Evolutionary biology ,Microbial Evolution ,Mycovirus ,Enzymology ,Parasitology ,Immunologic diseases. Allergy - Abstract
Mycoviruses are an important component of the virosphere, but our current knowledge of their genome organization diversity and evolution remains rudimentary. In this study, the mycovirus composition in a hypovirulent strain of Sclerotinia sclerotiorum was molecularly characterized. Nine mycoviruses were identified and assigned into eight potential families. Of them, six were close relatives of known mycoviruses, while the other three had unique genome organizations and evolutionary positions. A deltaflexivirus with a tripartite genome has evolved via arrangement and horizontal gene transfer events, which could be an evolutionary connection from unsegmented to segmented RNA viruses. Two mycoviruses had acquired a second helicase gene by two different evolutionary mechanisms. A rhabdovirus representing an independent viral evolutionary branch was the first to be confirmed to occur naturally in fungi. The major hypovirulence-associated factor, an endornavirus, was finally corroborated. Our study expands the diversity of mycoviruses and potential virocontrol agents, and also provides new insights into virus evolutionary modes including virus genome segmentation., Author summary Identification of mycoviruses in phytopathogenic fungi is necessary for understanding the origin of viruses and developing virocontrol strategies to protect plants. Nine mycoviruses with RNA genomes were identified in a hypovirulent strain of Sclerotinia sclerotiorum and were classified into eight potential viral families, suggesting that the composition of mycoviral communities was complex in this single fungal strain. They included four previously characterized mycoviruses and three distant relatives of known mycoviruses, as well as the first reports of a deltaflexivirus with a tripartite genome, and a fungal rhabdovirus. In addition, we found an endornavirus associated with hypovirulence in a phytopathogenic fungus. Our study makes a significant contribution because it not only expands the diversity-related knowledge of mycoviruses and potential virocontrol agents, but also provides new insights into mycovirus evolution.
- Published
- 2021