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An extracellular aspartic protease functions in Arabidopsis disease resistance signaling
Author(s) -
Xia Yiji,
Suzuki Hideyuki,
Borevitz Justin,
Blount Jack,
Guo Zejian,
Patel Kanu,
Dixon Richard A,
Lamb Chris
Publication year - 2004
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600086
Subject(s) - biology , pseudomonas syringae , arabidopsis , arabidopsis thaliana , protease , microbiology and biotechnology , genetics , virology , gene , mutant , biochemistry , enzyme
We have used activation tagging with T‐DNA carrying cauliflower mosaic virus 35S enhancers to investigate the complex signaling networks underlying disease resistance in Arabidopsis . From a screen of ∼5000 lines, we identified constitutive disease resistance ( CDR1 ) encoding an apoplastic aspartic protease, the overexpression of which causes dwarfing and resistance to virulent Pseudomonas syringae . These phenotypes reflect salicylic‐acid‐dependent activation of micro‐oxidative bursts and various defense‐related genes. Antisense CDR1 plants were compromised for resistance to avirulent P. syringae and more susceptible to virulent strains than wild type. CDR1 accumulates in intercellular fluid in response to pathogen attacks. Induction of CDR1 generates a small mobile signal, and CDR1 action is blocked by the protease inhibitor pepstatin and by mutations in the protease active sites. We propose that CDR1 mediates a peptide signal system involved in the activation of inducible resistance mechanisms.