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An F‐box gene, CPR30 , functions as a negative regulator of the defense response in Arabidopsis
Author(s) -
Gou Mingyue,
Su Nan,
Zheng Jun,
Huai Junling,
Wu Guangheng,
Zhao Jinfeng,
He Junguang,
Tang Dingzhong,
Yang Shuhua,
Wang Guoying
Publication year - 2009
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.2009.03995.x
Subject(s) - arabidopsis , pseudomonas syringae , biology , microbiology and biotechnology , arabidopsis thaliana , mutant , npr1 , systemic acquired resistance , genetics , plant disease resistance , gene , plant defense against herbivory , heart failure , natriuretic peptide , medicine
Summary Arabidopsis gain‐of‐resistance mutants, which show HR‐like lesion formation and SAR‐like constitutive defense responses, were used well as tools to unravel the plant defense mechanisms. We have identified a novel mutant, designated constitutive expresser of PR genes 30 ( cpr30 ), that exhibited dwarf morphology, constitutive resistance to the bacterial pathogen Pseudomonas syringae and the dramatic induction of defense‐response gene expression. The cpr30 ‐conferred growth defect morphology and defense responses are dependent on ENHANCED DISEASE SUSCEPTIBILITY 1 ( EDS1 ), PHYTOALEXIN DEFICIENT 4 ( PAD4 ), and NONRACE‐SPECIFIC DISEASE RESISTANCE 1 ( NDR1 ). Further studies demonstrated that salicylic acid (SA) could partially account for the cpr30 ‐conferred constitutive PR1 gene expression, but not for the growth defect, and that the cpr30 ‐conferred defense responses were NPR1 independent. We observed a widespread expression of CPR30 throughout the plant, and a localization of CPR30‐GFP fusion protein in the cytoplasm and nucleus. As an F‐box protein, CPR30 could interact with multiple Arabidopsis‐SKP1‐like (ASK) proteins in vivo . Co‐localization of CPR30 and ASK1 or ASK2 was observed in Arabidopsis protoplasts. Based on these results, we conclude that CPR30, a novel negative regulator, regulates both SA‐dependent and SA‐independent defense signaling, most likely through the ubiquitin‐proteasome pathway in Arabidopsis.