title: Amino acids, iron, and growth rate as key factors influencing production of the Pseudomonas putida BTP1 benzylamine derivative involved in systemic resistance induction in different plants.
abstract: The biological control bacterium Pseudomonas putida BTP1 exerts its protective effect mostly by inducing an enhanced state of resistance in the host plant against pathogen attack [induced systemic resistance (ISR)]. We previously reported that a specific compound derived from benzylamine may be involved in the elicitation of the ISR phenomenon by this Pseudomonas strain. In this article, we provide further information about the N,N-dimethyl-N-tetradecyl-N-benzylammonium structure of this determinant for ISR and show that the benzylamine moiety may be important for perception of the molecule by root cells of different plant species. We also investigated some regulatory aspects of elicitor production with the global aim to better understand how in situ expression of these ISR elicitors can be modulated by physiological and environmental factors. The biosynthesis is clearly related to secondary metabolism, and chemostat experiments showed that the molecule is more efficiently produced at low cell growth rate. Interestingly, the presence of free amino acids in the environment is necessary for optimal production, and a specific positive effect of phenylalanine was evidenced in pulsed continuous cultures. The influence of other abiotic factors, such as mineral content, oxygen concentration, or pH, on elicitor production is also reported and discussed with respect to the specific conditions that the producing strain undergoes in the rhizosphere environment.
authors.affiliation: Centre Wallon de Biologie Industrielle, Service de Technologie Microbienne, University of Liège, Boulevard du Rectorat 29, Bâtiment B40, 4000 Liège, Belgium. ongena.m@fsagx.ac.be
authors.forename: Marc
authors.initials: M
authors.lastname: Ongena
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jourdan
authors.forename: Akram
authors.initials: A
authors.lastname: Adam
authors.forename: Mathias
authors.initials: M
authors.lastname: Schäfer
authors.forename: Herbert
authors.initials: H
authors.lastname: Budzikiewicz
authors.forename: Philippe
authors.initials: P
authors.lastname: Thonart
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000898:Antibiosis; D001596:Benzylamines / Q000737:chemistry / Q000378:metabolism*; D018533:Biomass; D020171:Botrytis / Q000472:pathogenicity; D050260:Carbohydrate Metabolism; D018553:Cucumis sativus / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000382:microbiology; D013058:Mass Spectrometry; D010100:Oxygen / Q000378:metabolism; D027805:Phaseolus / Q000382:microbiology; D010649:Phenylalanine / Q000378:metabolism; D010944:Plants / Q000382:microbiology*; D016958:Pseudomonas putida / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
chemical_list: D000596:Amino Acids; D001596:Benzylamines; D010649:Phenylalanine; C030796:benzylamine; D007501:Iron; D010100:Oxygen