title: Ralstonia solanacearum induces soluble amine-oxidase activity in Solanum torvum stem calli.
abstract: Solanum torvum is reported to carry resistance to bacterial wilt caused by Ralstonia solanacearum. So, this wild species is used as rootskock for eggplants or tomatoes in naturally infected soil. This study aimed to investigate the involvement of the polyamine metabolism pathway in the resistance mechanisms of this species. Calli induced from Solanum torvum stem explants were inoculated with the bacteria under partial vacuum. All calli showed a hypersensitive response after infiltration. Furthermore, amine oxidase activity with aldehyde and H(2)O(2) production was detected in soluble protein extracts of calli infiltrated by the bacteria. Due to its preferential affinity for aliphatic amines, this enzyme was supposed to have amine oxidase-like (AO-like) activity. Moreover, the length of aliphatic chain cycle altered the oxidative deamination kinetics of potential substrates. The AO-like catalytic activity was significantly inhibited by chelator agents such as ethylene-diamine-tretraacetic (EDTA), and also by semi-carbazide as aminoguanidine. These results suggested that (i) the prosthetic group of the AO-like enzyme could be a tyrosine-derived 6-hydroxytopaquinone structure, copper containing; (ii) this enzyme could be a semi-carbazide sensitive amine oxidase (SSAO).
authors.affiliation: UMR C53 Peuplements végétaux et bioagresseurs en milieu tropical Université de La Réunion-CIRAD, CIRAD, Pôle de Protection des Plantes, Ligne Paradis, 97410 Saint Pierre, La Réunion, France. marcel.aribaud@cirad.fr
authors.forename: Marcel
authors.initials: M
authors.lastname: Aribaud
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Jégo
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Wicker
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fock
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000737:chemistry / Q000378:metabolism*; D000588:Amines / Q000378:metabolism; D055162:Biocatalysis / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D005557:Formaldehyde / Q000378:metabolism; D006146:Guanidines / Q000494:pharmacology; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D018547:Plant Stems / Q000201:enzymology / Q000378:metabolism / Q000382:microbiology*; D011073:Polyamines / Q000378:metabolism; D043368:Ralstonia solanacearum / Q000502:physiology*; D032322:Solanum / Q000201:enzymology / Q000378:metabolism / Q000382:microbiology*; D012995:Solubility; D013379:Substrate Specificity; D046509:Tissue Culture Techniques
chemical_list: D000588:Amines; D002614:Chelating Agents; D006146:Guanidines; D010940:Plant Proteins; D011073:Polyamines; D005557:Formaldehyde; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D006631:Amine Oxidase (Copper-Containing); C004479:pimagedine