title: Syringolide 1 Triggers Ca2+ Influx, K+ Efflux, and Extracellular Alkalization in Soybean Cells Carrying the Disease-Resistance Gene Rpg4.
abstract: Alleles of avirulence gene D (avrD) specify the production by bacteria of syringolides that elicit the hypersensitive response in soybean (Glycine max) plants carrying the disease-resistance gene Rpg4, but not rpg4 plants. Syringolide 1 caused extracellular alkalization, K+ efflux, and Ca2+ influx about 30 min after addition to suspension-cultured cells of two Rpg4 cultivars, Harosoy and Flambeau, but not in two rpg4 cultivars, Acme and Merit. All responses were sustained for at least 1.5 h and were inhibited by La3+, which blocks certain Ca2+ channels. These results suggest that syringolide 1 activates a Ca2+ influx-dependent signaling pathway only in Rpg4 soybean cells.
authors.affiliation: Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706 (M.M.A.).
authors.forename: M. M.
authors.initials: MM
authors.lastname: Atkinson
authors.forename: S. L.
authors.initials: SL
authors.lastname: Midland
authors.forename: J. J.
authors.initials: JJ
authors.lastname: Sims
authors.forename: N. T.
authors.initials: NT
authors.lastname: Keen