Production of syringotoxin and other bioactive peptides by Pseudomonas fuscovaginae

• Published in: Physiological and molecular plant pathology Vol. 48; no. 4; pp. 217 - 231
• Main Authors: Flamand, M.-C., Pelsser, S., Ewbank, E., Maraite, H.
• Format: Journal Article
• Language: English
• Published: London Elsevier India Pvt Ltd 1996; Elsevier
• Subjects: Bacterial plant pathogens; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Geotrichum candidum; Oryza sativa; Pathology. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Pseudomonas fuscovaginae; Pseudomonas syringae syringae; Pseudomonadales; Monocotyledones; Biochemical analysis; Pathophysiology; Plant pathogen; Phytotoxin; Peptides; Etiopathogenesis; Chemical structure; HPLC chromatography; Biochemistry; Cereal crop; Biological activity; Characterization; Biological compound; Oryza sativa; Molecular parameter; Gramineae; Angiospermae; Production; Bacteria; Pseudomonadaceae; Spermatophyta
• ISSN: 0885-5765; 1096-1178
• DOI: 10.1006/pmpp.1996.0019

The application of a cell-free extract from a broth culture of Pseudomonas fuscovaginaeto rice plants produced leaf sheath necrosis and inhibited panicle emergence typical of bacterial sheath rot. The extract was also fungistatic to Geotrichum candidumand displayed amphipathic properties. The toxic activity was associated with peptidic substances of less than 5000Da, migrating in a single broad band on SDS–PAGE. The toxins were precipitated by desoxycholate/trichloroacetic acid and reverse-phase HPLC of the precipitate showed the presence of five peptidic compounds (A, B, C, D and E), as well as two others (fuscopeptins A and B) which were not characterized in this study. Using FAB-MS, the MH +ions of the peptides, A to E were 1108, 1102, 1118, 1136 and 1152, respectively. The most abundant peptide, D, was characterized by amino acid analysis, fatty acid methyl ester analysis and FAB-MS of the by-products from mild alkaline hydrolysis. The chemical structure of D was identical to syringotoxin (C 48H 82O 18N 11Cl), a phytotoxin produced by P. syringaepv. syringae.Moreover, HPLC analysis of this compound indicated that compound D had the same retention time as the syringotoxin standard obtained from citrus strains of P. syringaepv. syringae.