Further insight into genetic variation and haplotype diversity of Cherry virus A from China

PLoS One. 2017 Oct 11;12(10):e0186273. doi: 10.1371/journal.pone.0186273. eCollection 2017.

Abstract

Cherry virus A (CVA) infection appears to be prevalent in cherry plantations worldwide. In this study, the diversity of CVA isolates from 31 cherry samples collected from different orchards around Bohai Bay in northeastern China was analyzed. The complete genome of one of these isolates, ChYT52, was found to be 7,434 nt in length excluding the poly (A) tail. It shares between 79.9-98.7% identity with CVA genome sequences in GenBank, while its RdRp core is more divergent (79.1-90.7% nt identity), likely as a consequence of a recombination event. Phylogenetic analysis of ChYT52 genome with CVA genomes in Genbank resulted in at least 7 major clusters plus additional 5 isolates alone at the end of long branches suggesting the existence of further phylogroups diversity in CVA. The genetic diversity of Chinese CVA isolates from 31 samples and GenBank sequences were analyzed in three genomic regions that correspond to the coat protein, the RNA-dependent RNA polymerase core region, and the movement protein genes. With few exceptions likely representing further recombination impact, the trees various trees are largely congruent, indicating that each region provides valuable phylogenetic information. In all cases, the majority of the Chinese CVA isolates clustering in phylogroup I, together with the X82547 reference sequence from Germany. Statistically significant negative values were obtained for Tajima's D in the three genes for phylogroup I, suggesting that it may be undergoing a period of expansion. There was considerable haplotype diversity in the individual samples and more than half samples contained genetically diverse haplotypes belonging to different phylogroups. In addition, a number of statistically significant recombination events were detected in CVA genomes or in the partial genomic sequences indicating an important contribution of recombination to CVA evolution. This work provides a foundation for elucidation of the epidemiological characteristics and evolutionary history of CVA populations.

MeSH terms

  • Base Sequence
  • China
  • Genetic Variation*
  • Genome, Viral
  • Haplotypes / genetics*
  • Nucleotides / genetics
  • Phylogeny
  • Plant Diseases / virology
  • Plant Viruses / genetics*
  • Plant Viruses / isolation & purification
  • Prunus / virology
  • Real-Time Polymerase Chain Reaction
  • Recombination, Genetic / genetics
  • Sequence Analysis, DNA

Substances

  • Nucleotides

Grants and funding

This work was supported by the National Natural Science Foundation of China [grant number 31471752] and the Special Fund for Agro-scientific Research in the Public Interest [grant number 201203076] to ML. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.