[en] The ability of Pseudomonas putida BTP1 to induce resistance in bean to Botrytis cinerea was demonstrated in soil experiments on plants pre-inoculated at the root level with the bacteria before challenge with the leaf pathogen. As a first step to characterize the molecules from BTP1 responsible for induction of systemic resistance in bean, heat-killed cells and supernatant from culture in an iron-limited medium were tested for their protective effect. Most of the resistance-eliciting activity of the strain was retained in the crude cell-free culture fluid. In vivo assays with samples from successive fractionation steps of the BTP1 supernatant led, (i) to the conclusion that salicylic acid, pyochelin and pyoverdin, previously identified as Pseudomonas determinants for induced systemic resistance (ISR), were not involved in systemic resistance triggered by BTP1, and (ii) to the isolation of fractions containing one main metabolite that retained most of the resistance-inducing activity in bean. Although this molecule remains to be structurally characterized, its isolation is an addition to the range of determinants from plant growth-promoting rhizobacteria (PGPR) known to stimulate plant defences.
Budzikiewicz H. (1993) Secondary metabolites from fluorescent pseudomonads. FEMS Microbiology Reviews 104:209-228.
De Meyer G., Höfte M. (1997) Salicylic acid produced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 induces resistance to leaf infection by Botrytis cinerea on bean. Phytopathology 87:588-593.
De Meyer G., Capiau K., Audenaert K., Buchala A., Métraux J.P., Höfte M. (1999) Nanogram amounts of salicylic acid produced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 activate the systemic acquired resistance pathway in bean. Molecular Plant-Microbe Interactions 12:450-458.
Duffy B.K., Défago G. (1999) Environmental factors modulating antibiotic and siderophore biosynthesis by Pseudomonas fiuorescens biocontrol strains. Applied and Environmental Microbiology 65:2429-2438.
Duijff B.J., Gianinazzi-Pearson V., Lemanceau P. (1997) Involvement of the outer-membrane lipopolysaccharides in the endophytic colonization of tomato roots by biocontrol Pseudomonas fluorescens WCS417r. New Phytologist 135:325-334.
Glick B.R. (1995) The enhancement of plant-growth by free-living bacteria. Canadian Journal of Microbiology 41:109-117.
Glick B.R., Karaturovic D.M., Newell P.C. (1995) A novel procedure for rapid isolation of plant growth promoting pseudomonads. Canadian Journal of Microbiology 41:533-536.
Hahn M.G. (1996) Microbial elicitors and their receptors in plants. Annual Review of Phytopathology 34:387-412.
Hoagland D.R., Arnon D.I. (1938) The water culture method for growing plants without soil. California Agricultural Experiment Station - Bulletin 347.
Höfte M., Buysens S., Koedam N., Cornélis P. (1993) Zinc affects siderophore-mediated high affinity iron uptake systems in the rhizosphere Pseudomonas aeruginosa 7NSK2. BioMetals 6:85-91.
Jacques P., Ongena M., Gwose I., Seinsche D., Schröder H., Delfosse P., Thonart P., Taraz K., Budzikiewicz H. (1995) Structure and characterization of isopyoverdin from Pseudomonas putida BTP1 and its relation to the biogenetic pathway leading to pyoverdines. Zeitschrift fur Naturforschung C-A Journal of Biosciences 50:622-629.
King E.O., Ward M.K., Raney D.E. (1954) Two simple media for the demonstration of pyocyanin and fluorescein. Journal of Laboratory and Clinical Medicine 44:301-307.
Kloepper J.W., Tuzun S., Kùc J.A. (1992) Proposed definitions related to induced disease resistance. Biocontrol Science and Technology 2:349-351.
Kloepper J.W., Tuzun S., Liu L., Wei G. (1993) Plant growth-promoting rhizobacteria as inducers of systemic disease resistance. Pest Management: Biologically Based Technologies , Lumsden RD and Vaughn JL (eds) American Chemical Society, Washington DC; 156-165.
Knoester M., Van Loon L.C., Van den Heuvel J., Hennig J., Bol J.F., Linthorst H.J.M. (1998) Ethylene-insensitive tobacco lacks non-host resistance against soil-born fungi. Proceedings of the National Academy of Sciences of the United States of America 95:1933-1937.
Leeman M., Van Pelt J.A., Den Ouden F.M., Heinsbrock M., Bakker P.A.H.M., Schippers B. (1995) Induction of systemic resistance against Fusarium wilt of radish by lipopolysaccharides of Pseudomonas fiuorescens. Phytopathology 85:1021-1027.
Leeman M., Den Ouden F.M., Van Pelt J.A., Dirkx F.P.M., Steijl H., Bakker P.H.A.M., Schippers B. (1996) Iron availability affects induction of systemic resistance to Fusarium wilt of radish by Pseudomonas fluorescens. Phytopathology 86:149-155.
Maurhofer M., Hase C., Meuwly P., Métraux J.P., Défago G. (1994) Induction of systemic resistance of tobacco to tobacco necrosis virus by the root-colonizing Pseudomonas fluorescens strain CHA0: Influence of the gacA gene and of pyoverdine production. Phytopathology 84:139-146.
Maurhofer M., Reimmann C., Schimidli-Sacherer P., Heeb S., Haas D., Défago G. (1998) Salicylic acid biosynthetic genes expressed in Pseudomonas fluorescens P3 improve the induction of systemic resistance in tobacco against tobacco necrosis virus. Phytopathology 88:678-684.
Meuwly P., Métraux J.P. (1993) Ortho-anisic acid as internal standard for the simultaneous quantitation of salicylic acid and its putative biosynthetic precursors in cucumber leaves. Analytical Biochemistry 214:500-505.
Ongena M., Daayf F., Jacques P., Thonart P., Benhamou N., Paulitz T.C., Cornélis P., Koedam N., Bélanger R.R. (1999) Protection of cucumber against Pythium root rot by fluorescent pseudomonads: Predominant role of induced resistance over siderophores and antibiosis. Plant Pathology 48:66-76.
Ongena M., Daayf F., Jacques P., Thonart P., Benhamou N., Paulitz T.C., Bélanger R.R. (2000) Systemic induction of phytoalexins in cucumber in response to treatments with fluorescent pseudomonads. Plant Pathology 49:523-530.
O'Sullivan D.J., O'Gara F. (1992) Traits of fluorescent Pseudomonas spp. involved in suppression of plant root pathogens. Microbiological Reviews 56:662-676.
Paulitz T.C., Loper J.E. (1991) Lack of a role for fluorescent siderophore production in the biological control of Pythium damping-off of cucumber by a strain of Pseudomonas putida. Phytopathology 81:930-935.
Pieterse C.M.J., Van Wees S.C.M., Van Pelt J.A., Knoester M., Laan R., Gerrits H., Weisbeek P.J., Van Loon L.C. (1998) A novel signaling pathway controlling induced disease resistance in plants. The Plant Cell 10:1571-1580.
Press C.M., Wilson M., Tuzun S., Kloepper J.W. (1997) Salicylic acid produced by Serratia marcescens 90-166 is not the primary determinant of induced systemic resistance in cucumber or tobacco. Molecular Plant - Microbe Interactions 10:761-768.
Raaijmakers J.M., Leeman M., Van Oorschot M.M.P., Van der Sluis I., Schippers B., Bakker P.A.H.M. (1995) Dose-response relationships in biological control of Fusarium wilt of radish by Pseudomonas spp. Phytopathology 85:1075-1081.
Reitz M., Rudolph K., Schröder I., Hoffmann-Hergarten S., Hallmann J., Sikora R.A. (2000) Lipopolysaccharides of Rhizobium etli strain G12 act in potato roots as an inducing agent of systemic resistance to infection by the cyst nematode Globodera pallida. Applied and Environmental Microbiology 66:3515-3518.
Ryals J.A., Neuenschwander U.H., Wilits M.G., Molina A., Steiner H.Y., Hunt M.D. (1996) Systemic acquired resistance. The Plant Cell 8:1809-1819.
Van Loon L.C., Bakker P.A.H.M., Pieterse C.M.J. (1998) Systemic resistance induced by rhizosphere bacteria. Annual Review of Phytopathology 36:453-483.
Van Peer R., Schippers B. (1992) Lipopolysaccharides of plant-growth promoting Pseudomonas sp. strain WCS417r induce resistance in carnation to Fusarium wilt. Netherlands Journal of Plant Pathology 98:129-139.
