Complete genome sequence of a novel endornavirus in the wheat sharp eyespot pathogen Rhizoctonia cerealis

We report here the presence of a novel double-stranded RNA (dsRNA) virus in an isolate (R0959) of the fungus Rhizoctonia cerealis, the causal agent of sharp eyespot of wheat in China. Sequence analysis showed that the dsRNA segment is 17,486 bp long and contains a single open reading frame (ORF) with the potential to encode a protein of 5,747 amino acids. The predicted protein contains conserved motifs of putative viral methyltransferase, helicase 1, and RNA-dependent RNA polymerase. Sequence similarity and phylogenetic analysis clearly place it in a distinct species within the genus Endornavirus, family Endornaviridae, and therefore we propose its name to Rhizoctonia cerealis endornavirus 1 (RcEV1). This is the first report of the full-length genomic sequence of a dsRNA mycovirus in R. cerealis.