Molecular characterization of Botrytis ourmia-like virus, a mycovirus close to the plant pathogenic genus Ourmiavirus

- We have characterized a new mycovirus (Botrytis ourmia-like virus) from Botrytis.
- BOLV is closer to the plant Ourmiavirus that to other mycoviruses.
- BOLV could represent the closest link between narnaviruses and ourmiaviruses.
- This finding will enhance our understanding the evolution of mycoviruses.

The molecular characterization of a novel single-stranded RNA virus, obtained by next generation sequencing using Illumina platform, in a field grapevine isolate of the plant pathogenic fungus Botrytis, is reported in this work. The sequence comparison of this virus against the NCBI database showed a strong identity with RNA dependent RNA polymerases (RdRps) of plant pathogenic viruses belonging to the genus Ourmiavirus, therefore, this novel virus was named Botrytis ourmia-like virus (BOLV). BOLV has one open reading frame of 2169 nucleotides, which encodes a protein of 722 amino acids showing conserved domains of plant RNA viruses RdRps such as the most conserved GDD active domain. Our analyses showed that BOLV is phylogenetically closer to the fungal Narnavirus and the plant Ourmiavirus than to Mitovirus of the family Narnaviridae. Hence, we proposed that BOLV might represent the link between fungal viruses of the family Narnaviridae and the plant ourmiaviruses.