@Article{IPB-2420, author = {Zimmermann, S. and Nürnberger, T. and Frachisse, J.-M. and Wirtz, W. and Guern, J. and Hedrich, R. and Scheel, D.}, title = {{Receptor-mediated activation of a plant Ca2\+-permeable ion channel involved in pathogen defense}}, year = {1997}, pages = {2751-2755}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, doi = {10.1073/pnas.94.6.2751}, volume = {94}, abstract = {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-activated 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.} }