A novel narnavirus from the plant-pathogenic fungus Magnaporthe oryzae

• DOI: 10.1007/s00705-020-04586-7
• Publication Date: 2020-03-10T12:02:52Z
• Authors: Yuan Lin; Jia Zhou; Xuan Zhou; Simin Shuai; Rendi Zhou; Hongliu An; Shouguo Fang; Songbai Zhang; Qingchao Deng
• Keywords: Magnaporthe; Pathogenic fungus; Medical microbiology; Pyricularia

A novel mycovirus with the proposed name "Magnaporthe oryzae narnavirus virus 1" (MoNV1), was described in the rice blast fungus Magnaporthe oryzae. The virus has a single-stranded (+ss) RNA genome of 2452 nucleotides, contains a single open reading frame (ORF) predicted to encode an RNA-dependent RNA polymerase (RDRP), and is closely related to some viruses of the genus Narnavirus, family Narnaviridae, including Aspergillus fumigatus narnavirus 1 (AfNV1), Neofusicoccum parvum narnavirus 2 (NpNV2) and Alternaria tenuissima narnavirus 1 (AtNV2). Genome sequence comparisons and phylogenetic analysis suggested that MoNV1 is a new member of the genus Narnavirus. The RDRPs of MoNV1 and some closely related narnaviruses do not contain a typical metal-binding "GDD" motif and catalytic site. Further studies are needed to investigate the replication mechanism of these viruses.