Characterization of a novel RNA virus from the phytopathogenic fungus Leptosphaeria biglobosa related to members of the genus Mitovirus
Mycovirus infection is a universal phenomenon in the major fungus groups. So far, however, mycoviruses have not been described in the phytopathogenic fungus Leptosphaeria biglobosa, the causal agent of phoma stem canker (blackleg). Here, we report the complete genome sequence of a novel mitovirus, Leptosphaeria biglobosa mitovirus 1 (LbMV1), isolated from the strain H3-38 of L. biglobosa. The LbMV1 genome comprises 2568 nucleotides with a low G+C content of 30%. Using the mitochondrial genetic code, the genome of LbMV1 was found to contain a single large open reading frame that encodes a predicted protein of 756 amino acids. Multiple alignment of the predicted protein sequence showed the highest similarity (51% identity) to the putative RNA-dependent RNA polymerase of Ophiostoma mitovirus 4. In addition, phylogenetic analysis grouped LbMV1 within the genus Mitovirus of the family Narnaviridae. Our results suggest that the double-stranded RNA found in strain H3-38 is the replicating genome of the mitovirus LbMV1, its deletion represents the first evidence of a mycovirus infecting L. biglobosa.
Compliance with ethical standards
This work was supported by the National Nature Science Foundation of China (31601588), National Key Research and Development Program of China (2017YFD0201100), and the China Agriculture Research System (CARS-13).
Conflict of interest
All authors declare that they have no conflicts of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
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