The Coat Protein of Turnip Crinkle Virus Suppresses Posttranscriptional Gene Silencing at an Early Initiation Step

Authors

Feng Qu, University of Nebraska-LincolnFollow
Tao Ren, University of Nebraska-Lincoln
Thomas Jack Morris, University of Nebraska-LincolnFollow

ORCID IDs

Feng Qu

Document Type

Article

Date of this Version

1-1-2003

Comments

Published in JOURNAL OF VIROLOGY, Jan. 2003, p. 511–522 Vol. 77, No. 1 0022-538X DOI: 10.1128/JVI.77.1.511–522.2003 Copyright © 2003, American Society for Microbiology. Used by permission.

Abstract

Posttranscriptional gene silencing (PTGS), or RNA silencing, is a sequence-specific RNA degradation process that targets foreign RNA, including viral and transposon RNA for destruction. Several RNA plant viruses have been shown to encode suppressors of PTGS in order to survive this host defense. We report here that the coat protein (CP) of Turnip crinkle virus (TCV) strongly suppresses PTGS. The Agrobacterium infiltration system was used to demonstrate that TCV CP suppressed the local PTGS as strongly as several previously reported virus-coded suppressors and that the action of TCV CP eliminated the small interfering RNAs associated with PTGS. We have also shown that the TCV CP must be present at the time of silencing initiation to be an effective suppressor. TCV CP was able to suppress PTGS induced by sense, antisense, and doublestranded RNAs, and it prevented systemic silencing. These data suggest that TCV CP functions to suppress RNA silencing at an early initiation step, likely by interfering the function of the Dicer-like RNase in plants.