The raspberry bushy dwarf virus 1b gene enables pollen grains to function efficiently in horizontal pollen transmission

Virology. 2020 Mar:542:28-33. doi: 10.1016/j.virol.2020.01.005. Epub 2020 Jan 14.

Abstract

Horizontal pollen transmission by the raspberry bushy dwarf virus 1b deletion mutant (RBΔ1bstop), which is defective in virus virulence, was significantly decreased compared to wild-type raspberry bushy dwarf virus (wtRBDV). We assessed accumulation of viral genomic (g) RNAs in pollen grains from RBΔ1bstop-infected plants and found that the pollen grains had less viral gRNA than those from wtRBDV-infected plants. In addition, pollen grains from 1b-expressing transgenic plants (1b-plants) infected with RBΔ1bstop were more efficient in horizontal virus transmission to healthy plants after pollination than pollen from RBΔ1bstop-infected wild type plants. Moreover, viral gRNA accumulation in pollen grains from RBΔ1bstop-infected 1b-plants was higher than in pollen from RBΔ1bstop-infected wild type plants. We suggest that 1b increases the amount of viral gRNAs released from elongating pollen grains.

Keywords: 1b gene; Pollen transmission; Pollen-born virus; Pollen-transmitted virus; RBDV; RNA silencing suppressor; Raspberry bushy dwarf virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Disease Transmission, Infectious
  • Genes, Viral*
  • In Situ Hybridization
  • Mutation
  • Nicotiana / genetics
  • Nicotiana / physiology
  • Nicotiana / virology
  • Plant Diseases / virology*
  • Plant Viruses / genetics*
  • Plant Viruses / pathogenicity
  • Plants, Genetically Modified
  • Pollen / virology*
  • Pollination
  • RNA Viruses / genetics
  • RNA Viruses / pathogenicity
  • RNA, Viral / genetics
  • RNA, Viral / metabolism
  • Rubus / physiology
  • Rubus / virology*

Substances

  • RNA, Viral