High affinity binding of a fungal oligopeptide elicitor to parsley plasma membranes triggers multiple defense responses.
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.
Nürnberger
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Max-Planck-Institut für Züchtungsforschung Abteilung Biochemie, Köln, Federal Republic of Germany.
Nennstiel
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Jabs
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Sacks
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Hahlbrock
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Scheel
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D000595:Amino Acid Sequence; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D006023:Glycoproteins / Q000378:metabolism*; D007477:Ions; D008861:Microsomes / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology*; D010838:Phytophthora / Q000737:chemistry*; D010936:Plant Extracts / Q000096:biosynthesis; D011485:Protein Binding; D011523:Protoplasts / Q000378:metabolism; D016897:Respiratory Burst; D012717:Sesquiterpenes; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D013729:Terpenes; D014158:Transcription, Genetic; D014675:Vegetables / Q000382:microbiology / Q000502:physiology*; D000094162:Phytoalexins
D006023:Glycoproteins; D007477:Ions; D009842:Oligopeptides; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins