An F‐box gene,CPR30, functions as a negative regulator of the defense response in Arabidopsis |
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Authors: | Mingyue Gou Nan Su Jun Zheng Junling Huai Guangheng Wu Jinfeng Zhao Junguang He Dingzhong Tang Shuhua Yang Guoying Wang |
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Affiliation: | 1. State Key Laboratory of Agrobiotechnology and National Center for Plant Gene Research (Beijing), China Agricultural University, Beijing 100193, China;2. Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China;3. State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China;4. State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China |
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Abstract: | 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. |
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Keywords: | F‐box protein negative regulator disease resistance salicylic acid ASK proteins |
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