Genome characterization of a novel mitovirus infecting the plant-pathogenic fungus Diaporthe sp

A previously uncharacterized mitovirus, designated as "Diaporthe mitovirus 3" (DMV3), was identified and isolated from the fungal pathogen Diaporthe sp. (isolate B-16) in this study. The DMV3 genome is a positive-sense, single-stranded RNA (+ ssRNA) molecule of 2,319 nucleotides (nt) with a GC content of 40%. It contains a single open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRp) consisting of 679 amino acids (aa) with a molecular mass of 76.4 kDa. Comparative analysis using BLASTp revealed that the RdRp of DMV3 exhibits the highest sequence similarity (64.56% identity) to Pestalotiopsis mitovirus 2 (PMV2). Phylogenetic analysis based on RdRp sequences demonstrated that DMV3 clusters together with PMV2 within a distinct clade, supporting its classification as a member of the genus Unuamitovirus within the family Mitoviridae.