Premium
A RanGAP protein physically interacts with the NB‐LRR protein Rx, and is required for Rx‐mediated viral resistance
Author(s) -
Sacco Melanie A.,
Mansoor Shahid,
Moffett Peter
Publication year - 2007
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2007.03213.x
Subject(s) - potato virus x , nicotiana benthamiana , biology , gene , r gene , gtpase , immunoprecipitation , genetics , gene silencing , plant disease resistance , potexvirus , effector , microbiology and biotechnology , virology , rna , coat protein
Summary Race‐specific disease resistance in plants is mediated by the products of host disease resistance ( R ) genes. Plant genomes possess hundreds of R gene homologs encoding nucleotide‐binding and leucine‐rich repeat (NB‐LRR) proteins. NB‐LRR proteins induce a disease resistance response following recognition of pathogen‐encoded avirulence (Avr) proteins. However, little is known about the general mechanisms by which NB‐LRR proteins recognize Avr proteins or how they subsequently induce defense responses. The Rx NB‐LRR protein of potato confers resistance to potato virus X (PVX). Using a co‐purification strategy, we have identified a Ran GTPase‐activating protein (RanGAP2) as an Rx‐interacting protein. We show by co‐immunoprecipitation that this interaction is mediated in planta through the putative signaling domain at the Rx amino terminus. Overexpression of RanGAP2 results in activation of certain Rx derivatives. Likewise, knocking down RanGAP2 expression in Nicotiana benthamiana by virus‐induced gene silencing compromises Rx‐mediated resistance to PVX. Thus, we have demonstrated a novel role for a RanGAP in the function of a plant disease resistance response.