Receptor-Mediated Activation of a Plant Ca2+-Permeable Ion Channel Involved in Pathogen Defense

Pathogen recognition at the plant cell surface typically results in the initiation of a multicomponent defense response. Transient influx of Ca2+across the plasma membrane is postulated to be part of the signaling chain leading to pathogen resistance. Patch-clamp analysis of parsley protoplasts reve...

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Veröffentlicht in:Proceedings of the National Academy of Sciences - PNAS 1997-03, Vol.94 (6), p.2751-2755
Hauptverfasser: Zimmermann, Sabine, Nurnberger, Thorsten, Frachisse, Jean-Marie, Wirtz, Wolfgang, Guern, Jean, Hedrich, Rainer, Scheel, Dierk
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Sprache:eng
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Zusammenfassung:Pathogen recognition at the plant cell surface typically results in the initiation of a multicomponent defense response. Transient influx of Ca2+across the plasma membrane is postulated to be part of the signaling chain leading to pathogen resistance. Patch-clamp analysis of parsley protoplasts revealed a novel Ca2+-permeable, La3+-sensitive plasma membrane ion channel of large conductance (309 pS in 240 mM CaCl2). At an extracellular Ca2+concentration of 1 mM, which is representative of the plant cell apoplast, unitary channel conductance was determined to be 80 pS. This ion channel (LEAC, for large conductance elicitor-aactivated ion channel) is reversibly activated upon treatment of parsley protoplasts with an oligopeptide elicitor derived from a cell wall protein of Phytophthora sojae. Structural features of the elicitor found previously to be essential for receptor binding, induction of defense-related gene expression, and phytoalexin formation are identical to those required for activation of LEAC. Thus, receptor-mediated stimulation of this channel appears to be causally involved in the signaling cascade triggering pathogen defense in parsley.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.94.6.2751