Molecular characterization of a novel mycovirus from Curvularia lunata in China

Abstract

A novel mycovirus was identified in Curvularia lunata in China using high-throughput sequencing and RT-PCR, and the virus was named "Curvularia lunata RNA virus 1" (ClRV1). The genome of ClRV1 consists of 3,742 nucleotides and contains two open reading frames (ORFs). In a BLASTn search based on the complete genome sequence of ClRV1, this virus was found to have the most sequence similarity to Erysiphe necator associated umbra-like virus 4 (EnUlV4) (74% identity, 54% query coverage), and BLASTp searches showed that the ClRV1 HP and RdRp shared the highest amino acid sequence identity of 66.5% and 74.7%, respectively, with the corresponding proteins of EnUlV4. Phylogenetic analysis based on RdRp amino acid sequences indicated that ClRV1 grouped together with EnUlV4 and a number of other mycoviruses that have been variously named ‘ambiguiviruses’, ‘mycotombusviruses’, and ‘umbramycoviruses’, which appears to justify the creation of a new order within the phylum Kitrinoviricota. This is the first report of the complete genome sequence of the novel mycovirus ClRV1 infecting Curvularia lunata.