Résumé
Over the past decade, virus metagenomics-based approaches have revolutionized the study of the viral diversity. Noteworthy, these metagenomics approaches have often required an initial step to enrich viral nucleic acids aiming at improving virus detection efficiency. Double-stranded RNA (dsRNA) profiling, one of these viral nucleic acids enrichment-based metagenomics approaches, has proven useful for diagnoses or characterization of unreported RNA viruses. Various dsRNA enrichment methods have been developed, including the oldest traditional cellulose- based dsRNA binding and newer approaches using anti-dsRNA antibodies with specific dsRNA affinity. The added- value of this last method, primarily used in plant virology, lied in its possible adaptability to an automated and standardized format. Here, we evaluate the application of the anti-dsRNA antibody approach followed by sequence-independent RT- PCR and Nanopore sequencing to analyze the virome of four strains of the rice blast fungus Pyricularia oryzae. This fungus is potentially a good study model while it is a major agricultural pathogen causing significant rice yield losses globally and it is known to host multiple dsRNA, ssRNA(+), and ssRNA(-) mycoviruses, which can be found in single or multiple infections. Overall, we show that the diversity of identified mycoviruses includes members of the families Botourmiaviridae, Narnaviridae, Polymycoviridae, Mymonaviridae, Partitiviridae and Tombusviridae. Each of the four P. oryzae strains was infected by one or more mycoviruses. These preliminary results highlight the need for further studies to explore mycovirus-host interactions under various environmental conditions and stresses in order to better understand the potential impact of single or multiple mycoviruses infection on the development of the rice blast disease.