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  • Publication
    Accès libre
    Priming for enhanced defence responses by specific inhibition of the Arabidopsis response to coronatine
    (2011)
    Tsai, Chia-Hong
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    Singh, Prashant
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    Chen, Ching-Wei
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    Thomas, Jerome
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    Weber, Johann
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    Zimmerli, Laurent
    The priming agent β-aminobutyric acid (BABA) is known to enhance Arabidopsis resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 by potentiating salicylic acid (SA) defence signalling, notably PR1 expression. The molecular mechanisms underlying this phenomenon remain unknown. A genome-wide microarray analysis of BABA priming during Pst DC3000 infection revealed direct and primed up-regulation of genes that are responsive to SA, the SA analogue benzothiadiazole and pathogens. In addition, BABA was found to inhibit the Arabidopsis response to the bacterial effector coronatine (COR). COR is known to promote bacterial virulence by inducing the jasmonic acid (JA) response to antagonize SA signalling activation. BABA specifically repressed the JA response induced by COR without affecting other plant JA responses. This repression was largely SA-independent, suggesting that it is not caused by negative cross-talk between SA and JA signalling cascades. Treatment with relatively high concentrations of purified COR counteracted BABA inhibition. Under these conditions, BABA failed to protect Arabidopsis against Pst DC3000. BABA did not induce priming and resistance in plants inoculated with a COR-deficient strain of Pst DC3000 or in the COR-insensitive mutant coi1-16. In addition, BABA blocked the COR-dependent re-opening of stomata during Pst DC3000 infection. Our data suggest that BABA primes for enhanced resistance to Pst DC3000 by interfering with the bacterial suppression of Arabidopsis SA-dependent defences. This study also suggests the existence of a signalling node that distinguishes COR from other JA responses.
  • Publication
    Accès libre
    Priming: Getting Ready for Battle
    (2006)
    Conrath, Uwe
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    Beckers, Gerold J. M.
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    García-Agustín, Pilar
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    Jakab, Gábor
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    Mauch, Felix
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    Newman, Mari-Anne
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    Pieterse, Corné M. J.
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    Poinssot, Benoit
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    Pozo, María J.
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    Pugin, Alain
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    Schaffrath, Ulrich
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    Ton, Jurriaan
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    Wendehenne, David
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    Zimmerli, Laurent
    ;
    Infection of plants by necrotizing pathogens or colonization of plant roots with certain beneficial microbes causes the induction of a unique physiological state called “ priming”. The primed state can also be induced by treatment of plants with various natural and synthetic compounds. Primed plants display either faster, stronger, or both activation of the various cellular defense responses that are induced following attack by either pathogens or insects or in response to abiotic stress. Although the phenomenon has been known for decades, most progress in our understanding of priming has been made over the past few years. Here, we summarize the current knowledge of priming in various induced-resistance phenomena in plants.