title: Phytophthora parasitica elicitor-induced reactions in cells of Petroselinum crispum.
abstract: Cultured parsley (Petroselinum crispum) cells respond to treatment with elicitors derived from different species of the genus Phytophthora with transcript accumulation of defense-associated genes and the production of furanocoumarin phytoalexins. Pep-25, an oligopeptide fragment of a Phytophthora sojae 42-kDa cell wall protein, and a cell wall elicitor preparation derived from Phytophthora parasitica (Pp-elicitor) stimulate accumulation of the same gene transcripts and formation of the same pattern of furanocoumarins. Treatment of cultured cells and protoplasts with proteinase-digested Pp-elicitor identified proteinaceous constituents as active eliciting compounds in parsley. Similar to Pep- 25, Pp-elicitor induced effluxes of K+ and Cl- and influxes of protons and Ca2+. Concomitantly, as monitored in aequorin-transgenic parsley cell lines both elicitors induced an immediate increase in the cytoplasmic Ca2+ concentration up to sustained levels of 175 nM (Pp-elicitor) or 300 nM (Pep-25), respectively. The signature of the Ca2+ response differed greatly between the two elicitors tested. Extracellular Ca2+ proved essential for activation of an oxidative burst, MAP kinase activity and phytoalexin production by either elicitor. While Pp-elicitor induced a qualitatively similar spectrum of defense responses as did Pep-25, elicitor-specific quantitative differences in response intensity and kinetics suggest activation of a conserved signaling cascade through separate ligand binding sites.
authors.affiliation: Institute of Plant Biochemistry, Department of Stress and Developmental Biology, Halle/Saale, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Fellbrich
authors.forename: B
authors.initials: B
authors.lastname: Blume
authors.forename: F
authors.initials: F
authors.lastname: Brunner
authors.forename: H
authors.initials: H
authors.lastname: Hirt
authors.forename: T
authors.initials: T
authors.lastname: Kroj
authors.forename: W
authors.initials: W
authors.lastname: Ligterink
authors.forename: A
authors.initials: A
authors.lastname: Romanski
authors.forename: T
authors.initials: T
authors.lastname: Nürnberger
mesh_terms: D019661:Apiaceae / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002473:Cell Wall / Q000502:physiology; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism; D005656:Fungal Proteins / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D010838:Phytophthora; D010936:Plant Extracts / Q000235:genetics; D011188:Potassium / Q000378:metabolism; D011523:Protoplasts / Q000502:physiology; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins
chemical_list: D002712:Chlorides; D005656:Fungal Proteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; C110312:elicitor protein, Phytophthora parasitica; D011188:Potassium; D002118:Calcium; D000094162:Phytoalexins