Molecular and biological characterization of a partitivirus from .

is a thermo-tolerant, ubiquitous fungus commonly found in food products, indoor environments, soil and clinical samples. It is a well-known biocontrol agent used against phytopathogenic fungi and its metabolites have many industrial applications. Rare reports of related human infections have been found in the medical literature. In this study, we report for the first time the infection of isolated from a soil sample collected in a rice field with a double-stranded RNA virus, Paeciliomyces variotii partitivirus 1 (PvPV-1) in the family harboured icosahedral virus particles 30 nm in diameter with two dsRNA segments 1758 and 1356 bp long. Both dsRNA1 and dsRNA2 have a single open reading frame encoding proteins of 63 and 40 kDa, respectively. These proteins have significant similarity to the RNA-dependent RNA polymerase and capsid protein encoded by the genomic segments of several viruses from the family . Phylogenetic analysis revealed that PvPV-1 belongs to the family but in an unclassified group/genus, tentatively nominated Zetapartitivirus. PvPV-1 was found to increase the growth rate of the host fungus, as indicated by time course experiments performed on a range of different media for virus-infected and virus-free isogenic lines. Further, dual-culture assays performed for both isogenic lines confirmed the antagonistic potential of against other phytopathogenic fungi. The findings of this study assist us in understanding as a potential biocontrol agent, together with plant-fungus-virus interactions.