Molecular characterization of an unusual new plant RNA virus reveals an evolutionary link between two different virus families

PLoS One. 2018 Oct 22;13(10):e0206382. doi: 10.1371/journal.pone.0206382. eCollection 2018.

Abstract

An unusual novel plant virus provisionally named goji berry chlorosis virus (GBCV) was isolated from goji berry plants (Lycium chinense Miller) showing chlorosis symptoms and its complete genome sequence was determined. The viral genome consists of a positive-sense single-stranded RNA of 10,100 ribonucleotides and contains six open reading frames (ORFs). Electron microscopy showed that the viral genome is packaged as a filamentous particle with an average length of approximately 850 nm. Phylogenetic analysis and amino acid similarity analysis of the encoded ORFs revealed that this new virus could be classified in an intermediate position between the families Benyviridae and Virgaviridae. The GBCV 200-kDa replicase (ORF1) is more similar to benyvirus replicases than to virgavirus replicases, while its 17-kDa coat protein (CP, ORF2) is more closely related with virgavirus CPs than benyvirus CPs. ORF3 was predicted to produce a C-terminally extended protein from ORF2 via frameshifting. While ORF4 (45-kDa), ORF5 (44-kDa), and ORF6 (16-kDa) have no apparent sequence homology with other known viruses, ORF5 is predicted to encode a movement protein (MP) that is phylogenetically related to the furovirus MP and ORF6 was experimentally proven to encode a viral suppressor of RNA silencing. These unusual characteristics suggest that GBCV may represent an evolutionary link between the families Benyviridae and Virgaviridae and indicate the existence of a novel, unidentified virus group.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Capsid Proteins / genetics
  • Lycium / virology*
  • Microscopy, Electron
  • Open Reading Frames / genetics
  • Phylogeny
  • RNA Viruses / classification
  • RNA Viruses / genetics*
  • RNA Viruses / isolation & purification
  • RNA, Viral / chemistry
  • RNA, Viral / genetics
  • RNA, Viral / metabolism
  • Sequence Alignment
  • Sequence Analysis, RNA

Substances

  • Capsid Proteins
  • RNA, Viral

Grants and funding

This research was supported in part by grants from the Next-Generation BioGreen 21 Program (PJ013129) funded by the Rural Development Administration of Korea, and by the Young Researcher Program (2018R1C1B5029927) funded by the National Research Foundation of Korea to JKS.