Molecular characterization of a novel fusarivirus infecting the plant-pathogenic fungus Alternaria solani

A novel mycovirus belonging to the proposed family Fusariviridae was discovered in Alternaria solani by sequencing a cDNA corresponding to double-stranded RNA extracted from this phytopathogenic fungus. The virus was tentatively named Alternaria solani fusarivirus 1 (AsFV1). AsFV1 has a single-stranded positive-sense (+ssRNA) genome of 6845 nucleotides containing three open reading frames (ORFs) and a poly(A) tail. The largest ORF, ORF1, encodes a large polypeptide of 1,556 amino acids (aa) with conserved RNA-dependent RNA polymerase and helicase domains. The ORF2 and ORF3 have overlapping regions, encoding a putative protein of 522 amino acids (aa) and a putative protein of 105 amino acids (aa), respectively, both of unknown function. A multiple sequence alignment and phylogenetic analysis revealed that AsFV1 could be a new member of the Fusariviridae. This is the first report of the full-length nucleotide sequence of a fusarivirus that infects Alternaria solani.

Automated summary

A novel mycovirus, named Alternaria solani fusarivirus 1 (AsFV1), was discovered in Alternaria solani with a genome of 6845 nucleotides. AsFV1 contains three ORFs and a poly(A) tail, and could be a new member of the Fusariviridae family based on sequence alignment and phylogenetic analysis. This is the first report of a fusarivirus infecting Alternaria solani with its full-length nucleotide sequence.