Four distinct isolates of a novel polymycovirus identified in Setosphaeria turcica

AbstractIsolation and analysis of double-stranded RNA (dsRNA) from the phytopathogenic fungusSetosphaeria turcica f. sp.zeae revealed the presence of a new double-stranded RNA (dsRNA) virus, tentatively named"Setosphaeria turcica polymycovirus 2" (StPmV2). The genome of StPmV2 consists of five segments (dsRNA1-5), ranging in size from 965 bp to 2462 bp. Each dsRNA contains one  open reading frame (ORF) flanked by 5' and 3' untranslated regions (UTRs) with conserved terminal sequences. The putative protein encoded by dsRNA1 shows 64.52% amino acid sequence identity to the RNA-dependent RNA polymerase (RdRp) of the most closely related virus, Cladosporium cladosporioides virus 1, which belongs to the familyPolymycoviridae. dsRNAs 2-4 encode the putative coat protein, methyltransferase (MTR), and proline-alanine-serine-rich protein (PASrp), respectively, and dsRNA5 encodes a protein of unknown function. Phylogenetic analysis based on the RdRp protein indicated that StPmV2 clustered with members of the familyPolymycoviridae and is therefore a new mycovirus belonging to the genusPolymycovirus in the familyPolymycoviridae. In addition, three other distinct isolates of StPmV2 were identified: one isolated fromS. turcica f. sp.zeae and two fromS. turcica f. sp.sorghi. To our knowledge, this is the first report of a polymycovirus infecting bothS. turcica f. sp.zeae andS. turcica f. sp.sorghi.

Source: Archives of Virology - June 23, 2023 Category: Virology Source Type: research