Molecular characterization of a novel fusagravirus in the phytopathogenic fungus Streptobotrys caulophylli

Arch Virol. 2022 Feb;167(2):619-623. doi: 10.1007/s00705-021-05328-z. Epub 2022 Jan 11.

Abstract

Streptobotrys caulophylli is a pathogenic fungus that causes leaf and stem blight in many plants. We report a novel fusagravirus identified in S. caulophylli strain STB-2, provisionally named "Streptobotrys caulophylli fusagravirus 1" (ScFV1). The full-length genome of ScFV1 is 9270 nucleotides (nt) long and putatively possesses two large open reading frames (ORF1 and ORF2), which are separated by an intergenic region of 955 nt. A conserved domain search revealed that ORF2 (1051 aa) encodes a putative RNA-dependent RNA polymerase (RdRp), whereas ORF1 (1404 aa) encodes a protein of unknown function. Homology searches and phylogenetic analysis of the putative RdRp suggest that ScFV1 is a new member of the proposed family "Fusagraviridae". This is the first report of a mycovirus infecting the fungus S. caulophylli.

MeSH terms

  • Ascomycota* / genetics
  • Fungal Viruses* / genetics
  • Genome, Viral
  • Open Reading Frames
  • Phylogeny
  • RNA Viruses* / genetics
  • RNA, Viral / genetics

Substances

  • RNA, Viral

Supplementary concepts

  • Streptobotrys caulophylli