Skip to content
Journal article

Strong host resistance targeted against a viral suppressor of the plant gene silencing defence mechanism

Li H, Lucy A, Guo H, Li W, Ji L, Wong S, Ding S ...see all

EMBO Journal, vol. 18, issue 10 (1999) pp. 2683-2691

  • 84

    Readers

    Mendeley users who have this article in their library.
  • 141

    Citations

    Citations of this article.
  • N/A

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

The 2b protein encoded by cucumber mosaic cucumovirus (Cmv2b) acts as an important virulence determinant by suppressing post-transcriptional gene silencing (PTGS), a natural plant defence mechanism against viruses. We report here that the tomato aspermy cucumovirus 2b protein (Tav2b), when expressed from the unrelated tobacco mosaic tobamovirus (TMV) RNA genome, activates strong host resistance responses to TMV in tobacco which are typical of the gene-for-gene disease resistance mechanism. Domain swapping between Cmv2b, which does not elicit these responses, and Tav2b, revealed functional domains in Tav2b critical for triggering virus resistance and hypersensitive cell death. Furthermore, substitution of two amino acids from Tav2b by those found at the same positions in Cmv2b, Lys21-->Val and Arg28-->Ser, abolished the ability to induce hypersensitive cell death and virus resistance. However, in Nicotiana benthamiana, a species related to tobacco, Tav2b functions as a virulence determinant and suppresses PTGS. Thus, a viral suppressor of the host gene silencing defence mechanism is the target of another independent host resistance mechanism. Our results provide new insights into the complex molecular strategies employed by viruses and their hosts for defence, counter-defence and counter counter-defence.

Author-supplied keywords

  • Avirulence gene
  • Cucumber mosaic virus
  • Disease resistance
  • Gene silencing
  • Hypersensitive response

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • Hong Wei Li

  • Andrew P. Lucy

  • Hui Shan Guo

  • Wan Xiang Li

  • Liang Hui Ji

  • Sek Man Wong

Cite this document

Choose a citation style from the tabs below