Mutual association of Broad bean wilt virus 2 VP37-derived tubules and plasmodesmata obtained from cytological observation

Sci Rep. 2016 Feb 23:6:21552. doi: 10.1038/srep21552.

Abstract

The movement protein VP37 of broad bean wilt virus 2 (BBWV 2) forms tubules in the plasmodesmata (PD) for the transport of virions between cells. This paper reports a mutual association between the BBWV 2 VP37-tubule complex and PD at the cytological level as determined by transmission electron microscopy. The generation of VP37-tubules within different PD leads to a different occurrence frequency as well as different morphology lines of virus-like particles. In addition, the frequency of VP37-tubules was different between PD found at different cellular interfaces, as well as between single-lined PD and branched PD. VP37-tubule generation also induced structural alterations of PD as well as modifications to the cell wall (CW) in the vicinity of the PD. A structural comparison using three-dimensional (3D) electron tomography (ET), determined that desmotubule structures found in the center of normal PD were absent in PD containing VP37-tubules. Using gold labeling, modification of the CW by callose deposition and cellulose reduction was observable on PD containing VP37-tubule. These cytological observations provide evidence of a mutual association of MP-derived tubules and PD in a natural host, improving our fundamental understanding of interactions between viral MP and PD that result in intercellular movement of virus particles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Wall / ultrastructure
  • Cell Wall / virology
  • Chenopodium quinoa / ultrastructure
  • Chenopodium quinoa / virology*
  • Fabavirus / metabolism
  • Fabavirus / ultrastructure*
  • Host-Pathogen Interactions
  • Microscopy, Electron, Transmission
  • Plant Leaves / ultrastructure
  • Plant Leaves / virology*
  • Plasmodesmata / ultrastructure
  • Plasmodesmata / virology*
  • Protein Transport
  • Viral Proteins / metabolism
  • Virion / metabolism
  • Virion / ultrastructure*

Substances

  • Viral Proteins