Characterization and complete genome sequences of two novel variants of the family Closteroviridae from Chinese kiwifruit

PLoS One. 2020 Nov 23;15(11):e0242362. doi: 10.1371/journal.pone.0242362. eCollection 2020.

Abstract

Two distinct closterovirus-like genome sequences (termed AdV-1 v1 and v2) were identified in Actinidia chinensis var. deliciosa 'Miliang-1' that had no disease symptoms using high-throughput sequencing. Using overlapping reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends, the genomic sequences of AdV-1 v1 and v2 were confirmed as 17,646 and 18,578 nucleotides in length, respectively. The two complete genomes contained 9 and 15 open reading frames, respectively, coding for proteins having domains typical of Closteroviridae, such as RNA-dependent RNA polymerase (RdRp), heat shock protein 70 homolog (HSP70h) and coat protein (CP). Sequence analysis showed that the amino acid sequences of RdRp, HSP70h, and CP of the two variants exhibited high similarity (> 80%), while their genomic organization was somewhat different. This suggested that the two viral genomes identified here are variants of the family Closteroviridae in a single kiwifruit host. Furthermore, phylogenetic relationship analysis revealed that the two variants had a closer relationship with the unclassified virus Persimmon virus B (PeVB) and Actinidia virus 1 (AcV-1) than with other members of the family Closteroviridae, as did their genomic organization. It is speculated that the two variants, together with PeVB and AcV-1 belong to a new subfamily of Closteroviridae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinidia / genetics
  • Actinidia / virology*
  • Amino Acid Sequence
  • Base Sequence
  • China
  • Closteroviridae / genetics*
  • Closterovirus / genetics
  • Fruit / genetics
  • Genome, Viral
  • Genomics
  • Open Reading Frames / genetics
  • Phylogeny
  • Plant Diseases / virology
  • RNA, Viral / genetics
  • Viral Proteins / genetics
  • Whole Genome Sequencing

Substances

  • RNA, Viral
  • Viral Proteins

Grants and funding

This research was funded by the Natural Science Foundation of Fujian Province (No.2018J05051), the Basic Science Foundation of Fujian Province (No.2015R1014-3, No.2018R1013-2, and No.2019R1028-5), and the Science Foundation of Fujian Academy of Agricultural Sciences (No.YC2017-2 and No.STIT2017-3-6).