Genomic organization of a novel victorivirus from the rice blast fungus Magnaporthe oryzae

Arch Virol. 2015 Nov;160(11):2907-10. doi: 10.1007/s00705-015-2562-4. Epub 2015 Aug 15.

Abstract

Two double-stranded RNA (dsRNA) mycoviruses were found in isolate QSP5 of the rice blast fungus Magnaporthe oryzae. Sequence analysis of the two dsRNA mycoviruses revealed that one is closely related to Magnaporthe oryzae virus 2 (MoV2), and the other one is related to Magnaporthe oryzae chrysovirus 1-A (MoCV1-A). Therefore, they were named Magnaporthe oryzae virus 3 (MoV3) and Magnaporthe oryzae chrysovirus 1-C (MoCV1-C), respectively. In this paper, the molecular and structural characteristics of MoV3 were analyzed in detail. The full genome sequence (5181 bp) of MoV3 was obtained by cDNA cloning. Sequence analysis indicated that MoV3 has two overlapping open reading frames (ORF1 and ORF2). The 5'-proximal ORF1 encodes a putative coat protein (CP) with a molecular weight of 80,939 Da; the 3'-proximal ORF2 encodes a putative RNA-dependent RNA polymerase (RdRp) with a molecular weight of 90,506 Da. The stop codon of ORF1 overlaps the start codon of ORF2, with the tetranucleotide sequence AUGA, which is characteristic of members of the genus Victorivirus of the family Totiviridae. Phylogenetic analysis of RdRp and CP further supported the view that MoV3, a novel mycovirus, belongs to the genus Victorivirus of the family Totiviridae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Genome, Viral*
  • Genomics
  • Magnaporthe / virology*
  • Molecular Sequence Data
  • Open Reading Frames
  • Phylogeny
  • Sequence Homology, Amino Acid
  • Totiviridae / classification
  • Totiviridae / genetics*
  • Totiviridae / isolation & purification*
  • Viral Proteins / chemistry
  • Viral Proteins / genetics

Substances

  • Viral Proteins