Molecular and Biological Characterization of the First Mymonavirus Identified in Fusarium oxysporum

Abstract

We characterized a negative sense single-stranded RNA mycovirus, Fusarium oxysporum mymonavirus 1 (FoMyV1), isolated from the phytopathogenic fungus Fusarium oxysporum. The genome of FoMyV1 is 10,114 nt, including five open reading frames (ORFs1–5) that are non-overlapping and linearly arranged. The largest, ORF5, encodes a large polypeptide L containing a conserved regions corresponding to Mononegavirales RNA-dependent RNA polymerase and mRNA-capping enzyme region V; the putative functions of the remaining four ORFs are unknown. The L protein encoded by ORF5 shared a high amino acid identity of 65% with that of Hubei rhabdo-like virus 4, a mymonavirus that associated with arthropods. However, the L protein of FoMyV1 also showed amino acid similarity (27–36%) with proteins of mynonaviruses that infect the phytopathogenic fungi Sclerotinia sclerotiorum and Botrytis cineaea. Phylogenetic analysis based on L protein showed that FoMyV1 is clustered with the members of the genus Hubramonavirus in the family Mymonaviridae. Moreover, we found that FoMyV1 could successfully transfer by hyphal anastomosis to a virus-free strain. FoMyV1 reduced the vegetative growth and conidium production of its fungal host but did not alter its virulence. To the best of our knowledge, this is not only the first mymonavirus described in the species F. oxysporum, but also the first Hubramonavirus species found to infect a fungus. However, the incidence of FoMyV1 infections in the tested F. oxysporum strains was only 1%.

Virome analysis of an ectomycorrhizal fungus Suillus luteus revealing potential evolutionary implications

“…Multiple alignments based on the RdRp of SlMyV1 and other selected mymonaviruses were conducted ( Figure S10 ). Four conserved motifs that were identified in other mymonaviruses were also detected in the RdRp of SlMyV1 ( Hao et al., 2018 ; Wang et al., 2022 ). In addition, phylogenetic analysis revealed that SlMyV1 clustered with members of the genus Sclerotimonavirus ( Figure 8 ), suggesting SlMyV1 should be a new member of this genus.…”

Metatranscriptome-based strategy reveals the existence of novel mycoviruses in the plant pathogenic fungus Fusarium oxysporum f. sp. cubense

“…dianthi mitovirus 1 (family Mitoviridae ), Fusarium oxysporum f. sp. dianthi hypovirus 2 (family Hypoviridae ), Fusarium oxysporum ourmia-like virus 1 (family Botourmiaviridae ), Hadaka Virus 1 (family Polymycoviridae ), and Fusarium oxysporum mymonavirus 1 (family Mymonaviridae ; Sharzei et al, 2007 ; Lemus-Minor et al, 2015 ; Sato et al, 2020 ; Torres-Trenas et al, 2020 ; Torres-Trenas and Pérez-Artés, 2020 ; Zhao et al, 2020 ; Wang et al, 2021 ; Wen et al, 2021 ; Wang J. et al, 2022 ). Of these reported mycoviruses, Fusarium oxysporum f. sp.…”

“…Of these reported mycoviruses, Fusarium oxysporum f. sp. dianthi virus 1 (FodV1), Fusarium oxysporum ourmia-like virus 1 (FoOuLV1) and FoMyV1 are capable of causing hypovirulence of host and can be used as biological control agents ( Lemus-Minor et al, 2019 ; Zhao et al, 2020 ; Wang J. et al, 2022 ). This study is the first report of seven partitiviruses from F. oxysporum .…”

Annual (2023) taxonomic update of RNA-directed RNA polymerase-encoding negative-sense RNA viruses (realm Riboviria: kingdom Orthornavirae: phylum Negarnaviricota)

“…emend. Snyder and Hansen) sampled in Luòhé (漯河市), Hénán Province (河南省), China [19]; • Hubramonavirus golovinomycesae for Golovinomyces cichoracearum GcM3_contig_4635, here renamed Golovinomyces cichoracearum negative-stranded RNA virus 1 (GcNSRV1), discovered by HTS in an ascomycete (erysiphaceaen Erysiphe cichoracearum [DC.] (1805)) sampled in Shady Grove, Maryland, USA [20]; and • Hubramonavirus vitis for grapevine-associated mononega-like virus 3 (GaMLV3) discovered by HTS in common grape vine (vitaceaen Vitis vinifera L.) sampled in the Veneto region of Italy [21].…”