A novel gammapartitivirus from the Penicillium oxalicum RCEF7482

Abstract Penicillium oxalicum, an essential biocontrol fungus in China, has been a subject of extensive study due to its role in combating various pathogenic fungi. Despite the prevalence of mycoviruses with double-stranded (ds) RNA genomes in filamentous fungi, no instances of mycovirus infection have been reported in P. oxalicum. In this investigation, we present the identification and characterization of a novel dsRNA virus isolated from P. oxalicum, designated as "Penicillium oxalicum partitivirus 1" (PoPV1). The genome of PoPV1 consists of two dsRNA segments, dsRNA1 (1,770 bp) and dsRNA2 (1,584 bp), each hosting a single open reading frame (ORF): ORF1 and ORF2. Comparative analysis revealed that PoPV1's RdRp and CP sequences share the highest identity (89.18% and 73.97%, respectively) with Penicillium aurantiogriseum partitivirus 1 (PaPV1). Motif analysis based on RdRp amino acid sequences places PoPV1 in the genus Gammapartitivirus within the familyPartitiviridae, with a distinctive motif VI (R/KV/ILGDD). Phylogenetic analysis further establishes PoPV1's close relationship with PaPV1, forming a unique clade within gammapartitiviruses. Consequently, we propose that Penicillium oxalicum partitivirus 1 represents a novel species in the genus Gammapartitivirus, marking the first reported case of dsRNA in P. oxalicum.