Complete genome sequence of a novel mycovirus isolated from the phytopathogenic fungus Corynespora cassiicola in China

• DOI: 10.1007/s00705-020-04723-2
• Publication Date: 2020-08-05T15:03:44Z
• Authors: Yanfen Wang; Hang Zhao; Caiying Xue; Chao Xu; Yuehua Geng; Rui Zang; Yuxia Guo; Haiyan Wu; Meng Zhang
• Keywords: 0301 basic medicine; China; Base Sequence; Whole Genome Sequencing; Genome, Viral; Fungal Viruses; Plants; RNA-Dependent RNA Polymerase; 3. Good health; Open Reading Frames; Viral Proteins; 03 medical and health sciences; Ascomycota; RNA, Viral; Sequence Alignment; Phylogeny; Plant Diseases; RNA, Double-Stranded

A novel mycovirus, named "Corynespora cassiicola bipartite mycovirus 1" (CcBV1), was isolated from a phytopathogenic fungus, Corynespora cassiicola, the causal agent of rubber leaf fall disease. The nucleotide sequence of the complete genome of CcBV1, which consists of two double-stranded RNA (dsRNA) segments, was determined. The first dsRNA is 2,002 bp in length and contains a single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) (69 kDa), while the second is 1,738 bp in length and contains a single ORF encoding a hypothetical protein of unknown function, with an approximately molecular weight of 36 kDa. The amino acid sequences of the both deduced proteins are most similar (58.9% and 45.1% identity, respectively) to those of Cryphonectria parasitica bipartite mycovirus 1 (CpBV1). Phylogenetic analysis indicated that CcBV1 clusters together with CpBV1 and other unassigned dsRNA mycoviruses. To the best of our knowledge, this represents the first report of a mycovirus infecting C. cassiicola.