High affinity binding of a fungal oligopeptide elicitor to parsley plasma membranes triggers multiple defense responses

• Published in: Cell Vol. 78; no. 3; p. 449
• Main Authors: Nürnberger, T, Nennstiel, D, Jabs, T, Sacks, W R, Hahlbrock, K, Scheel, D
• Format: Journal Article
• Language: English
• Published: United States 12-08-1994
• Subjects: Amino Acid Sequence; Binding Sites; Cell Membrane - metabolism; Cells, Cultured; Glycoproteins - metabolism; Ions; Microsomes - metabolism; Models, Biological; Molecular Sequence Data; Oligopeptides - pharmacology; Phytophthora - chemistry; Plant Extracts - biosynthesis; Protein Binding; Protoplasts - metabolism; Respiratory Burst; Sesquiterpenes; Signal Transduction; Structure-Activity Relationship; Terpenes; Transcription, Genetic; Vegetables - microbiology; Vegetables - physiology
• ISSN: 0092-8674
• DOI: 10.1016/0092-8674(94)90423-5

An oligopeptide of 13 amino acids (Pep-13) identified within a 42 kDa glycoprotein elicitor from P. mega-sperma was shown to be necessary and sufficient to stimulate a complex defense response in parsley cells comprising H+/Ca2+ influxes, K+/Cl- effluxes, an oxidative burst, defense-related gene activation, and phytoalexin formation. Binding of radiolabeled Pep-13 to parsley microsomes and protoplasts was specific, reversible, and saturable. Identical structural features of Pep-13 were found to be responsible for specific binding and initiation of all plant responses analyzed. The high affinity binding site recognizing the peptide ligand (KD = 2.4 nM) may therefore represent a novel class of receptors in plants, and the rapidly induced ion fluxes may constitute elements of the signal transduction cascade triggering pathogen defense in plants.