title: Molecular characterization of three mitoviruses co-infecting a hypovirulent isolate of Sclerotinia sclerotiorum fungus.
abstract: Three double-stranded RNAs (dsRNAs) of 2438 nts (A), 2588 nts (B), and 2744 nts (C), from a single isolate of Sclerotinia sclerotiorum were sequenced. All three sequences showed similarity to known mitoviruses, consisting of a single open reading frame (ORF) with the characteristic conserved motifs of RNA-dependent RNA polymerase (RdRp). Mitochondrial malformations and reduced virulence and growth were associated with the presence of the dsRNAs. The terminal sequences of the (+) strand of the three dsRNAs could be folded into stem-loop structures and the inverted terminal complimentary sequences of dsRNA-A potentially form a panhandle structure. Sequence A showed 91.6% aa similarity to the previously described Sclerotinia sclerotiorum mitovirus 2 and was tentatively assigned the acronym SsMV2/NZ1. Sequences B and C showed only 16.4% similarity to each other and 15-48% aa similarity to the previously described mitoviruses and consequently appear to be new mitoviruses.
authors.affiliation: Microbiology Department, School of Biological Sciences, The University of Auckland, PO Box 92019, Auckland 1010, New Zealand. mkha201@aucklanduni.ac.nz
authors.forename: Mahmoud E
authors.initials: ME
authors.lastname: Khalifa
authors.forename: Michael N
authors.initials: MN
authors.lastname: Pearson
mesh_terms: D001203:Ascomycota / Q000302:isolation & purification / Q000821:virology*; D016000:Cluster Analysis; D008928:Mitochondria / Q000648:ultrastructure / Q000821:virology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010802:Phylogeny; D012328:RNA Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase