Triticum mosaic poacevirus enlists P1 rather than HC-Pro to suppress RNA silencing-mediated host defense

Satyanarayana Tatineni, Feng Qu, Ruhui Li, T. Jack Morris, Roy French

Research output: Contribution to journalArticlepeer-review

60 Scopus citations


Triticum mosaic virus (TriMV) is the type species of the newly established Poacevirus genus in the family Potyviridae. In this study, we demonstrate that in contrast to the helper component-proteinase (HC-Pro) of Potyvirus species, the P1 proteins of TriMV and Sugarcane streak mosaic poacevirus function in suppression of RNA silencing (SRS). TriMV P1 effectively suppressed silencing induced by single- or double-stranded RNAs (ss/ds RNAs), and disrupted the systemic spread of silencing signals at a step after silencing signal production. Interestingly, contrary to enhanced SRS activity of potyviral HC-Pro by co-expression with P1, the presence of TriMV HC-Pro reduced SRS activity of TriMV P1. Furthermore, TriMV P1 suppressed systemic silencing triggered by dsRNA more efficiently than the HC-Pro of Turnip mosaic potyvirus. Furthermore, TriMV P1 enhanced the pathogenicity of a heterologous virus. Our results established poaceviral P1 as a potent RNA silencing suppressor that probably employs a novel mechanism to suppress RNA silencing-based antiviral defense.

Original languageEnglish (US)
Pages (from-to)104-115
Number of pages12
Issue number1
StatePublished - Nov 10 2012
Externally publishedYes


  • HC-Pro
  • Inhibition
  • P1
  • Poacevirus
  • Potyviridae
  • RNA silencing suppressor
  • Sugarcane streak mosaic virus
  • Systemic silencing
  • Wheat

ASJC Scopus subject areas

  • Virology


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