Molecular Characterization of a Novel Mycovirus Infecting the Entomopathogenic Fungus Beauveria Bassiana

Abstract

The entomopathogenic fungus Beauveria bassiana is used worldwide for its biological control. Seven dsRNA segments were detected from a single Beauveria bassiana strain RCEF 1446. High-throughput sequencing indicated the presence of three mycoviruses in the infected sample. Two known mycoviruses were identified as Beauveria bassiana Victorivirus 1 and Beauveria bassiana polymycovirus 1, and the novel mycovirus was designated as Beauveria bassiana bipartite mycovirus 1 (BbBV1). The complete sequence of the BbBV1 is described here. The mycovirus contains two dsRNA segments. The first dsRNA is 2,026 bp in length and encoding a RNA-dependent RNA polymerase (RdRp) (68.54 kDa), while the second segment encoding a hypothetical protein (35.55 kDa) of unknown function, was 1,810 bp in length. Moreover, the RdRp protein sequences showed the highest identity of 62.89% to Corynespora cassiicola bipartite mycovirus 1. Phylogenetic analysis of the RdRp reveals that the virus represents a distinct lineage of unassigned dsRNA mycoviruses infecting fungi.