title: Genomic characterization of a novel dsRNA virus detected in the phytopathogenic fungus Verticillium dahliae Kleb.
abstract: Four novel double-stranded RNA segments were detected in a Verticillium dahliae Kleb. strain (V. dahliae isolate 0-21), a causal fungal agent of Verticillium wilt disease of cotton. Each dsRNA genome segment contains a single large open reading frame (ORF) that encodes a distinctive protein with modest levels of sequence similarities to the corresponding putative proteins in the genus Chrysovirus. These include an RNA-dependent RNA polymerase (RdRp), a coat protein, an undefined replication-related protein and an ovarian tumor domain peptidase. Phylogenetic analysis of the four putative proteins unanimously indicated that they are evolutionarily related to viruses in Chrysovirus. The 5'- and 3'-untranslated regions of the four dsRNAs share highly similar internal sequence and contain conserved sequence stretches of UGAUAAAAAA(/U)UG(/U)AAAAA- (in the 5'-UTR) and -UUUACUACU (in the 3'-UTR), indicating that they have a common virus origin. Indeed, isometric virus-like particles (VLPs) with a diameter of approximately 34nm were extracted from the fungal mycelia, and the four dsRNA segments were also detected in the virus-like particle (VLP) fraction. These results suggest that the mycovirus with four different dsRNA genome segments from the fungal isolate 0-21 is a new member of the genus Chrysovirus. We named the virus Verticillium dahliae chrysovirus 1 (VdCV1).
authors.affiliation: Institute of Bioengineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China.
authors.forename: Yue-Fen
authors.initials: YF
authors.lastname: Cao
authors.forename: Xi-Wu
authors.initials: XW
authors.lastname: Zhu
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiang
authors.forename: De-Qiang
authors.initials: DQ
authors.lastname: Li
authors.forename: Jia-Rong
authors.initials: JR
authors.lastname: Yang
authors.forename: Qian-Zhuo
authors.initials: QZ
authors.lastname: Mao
authors.forename: Ji-Shuang
authors.initials: JS
authors.lastname: Chen
mesh_terms: D016000:Cluster Analysis; D016679:Genome, Viral; D003368:Gossypium / Q000382:microbiology; D008969:Molecular Sequence Data; D025282:Mycelium / Q000821:virology; D016366:Open Reading Frames; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D012328:RNA Viruses / Q000235:genetics* / Q000302:isolation & purification; D012330:RNA, Double-Stranded / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D020172:Verticillium / Q000302:isolation & purification / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics; D014771:Virion / Q000302:isolation & purification / Q000648:ultrastructure
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D014764:Viral Proteins