Abstract
Pseudomonas aureofaciens PA147-2 produces an antibiotic (Af+) which inhibits the growth of fungal phytopathogens on phosphate buffered potato dextrose agar (PBPDA). To determine the role of the antibiotic in disease suppression in vivo, PA147-2 and an antibiotic-deficient Tn5 mutant (Af-) PA109, were tested for their ability to suppress root rot of Asparagus officinalis seedlings caused by Phytophthora megasperma var sojae, in the glasshouse. Seedlings coinoculated with the pathogen and the wildtype strain PA147-2, showed a significantly reduced level of infection and disease severity compared to seedlings inoculated with the pathogen alone. However, 100% of seedlings treated with Af- mutant PA109 were diseased. Furthermore, a strain derived from mutant PA109, restored to Af+ through allele replacement of Tn5 by homologous recombination, gave similar levels of disease suppression as the wildtype. This suggests the antibiotic produced by PA147-2 is important for the control of P. megasperma in vitro as well as in planta. Treatment of seedlings with PA147-2 and derived strains including the Tn5 mutant (Af-) strain improved plant weight by 40–100% in the presence and absence of the pathogen suggesting PA147-2 also has a direct growth stimulatory effect independent of antibiotic production.
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References
Carruthers F L, Conner A J and Mahanty H K 1994 Identification of a genetic locus in Pseudomonas aureofaciens involved in fungal inhibition. Appl. Environ. Microbiol. 60, 71–77.
Davidson J 1988 Plant Beneficial Bacteria. Bio/Technology 6, 282–286.
Elad Y, Chet I and Baker R 1987 Increased growth response of plants induced by rhizobacteria antagonistic to soilborne pathogenic fungi. Plant and Soil 98, 325–330.
Falloon P C 1985 A method for screening asparagus (Asparagus officinalis L) seedlings for resistance to Phytophhthora root. roceedings of the 6th International Asparagus symposium, 5–8 August, Guelph. pp 220–227.
Falloon P G and Grogan R G 1991 Effect of root temperature, plant age, frequency and duration of flooding and inoculum placement and concentration on susceptibility of asparagus to Phytophthora rot. N.Z.J. Crop Hort. Sci. 19, 305–312.
Fravel D R 1988 Role of antibiosis in the biocontrol of plant diseases. Annu. Rev. Phytopathol. 26, 75–91.
Gutterson N 1990 Microbial fungicides: Recent approaches to elucidating mechanisms. Crit. Rev. Biotechnol. 10, 69–91.
Hamdan H, Weller D M and Thomashaw L S 1991 Relative importance of fluorescent siderophores and other factors in biological control of Gaeumannomyces graminis var tritici by Pseudomonas fluorescens 2–79 and M4–80R. Appl. Environ. Microbiol. 57, 3270–3277.
Homma Y 1994 Mechanisms in biological control-focused on the antibiotic pyrrolnitrin. In Proc. Third Int. Workshop, PGPR, Adelaide. pp 100–103.
Howell C R and Stipanovic R D 1979 Control of Rhizoctonia solani on cotton seedlings with Pseudomonas fluorescens and with an antibiotic production by the bacterium. Phytopathology 69, 480–482.
Howell C R and Stipanovic R D 1980 Suppression of Pythium ultimum-induced damping-off of cotton seedlings by Pseudomonas fluorescens and its antibiotic, Pyoluteorin. Phytopathology 70, 712–715.
Keel C, Wirthner Ph, Oberhansli Th, Voisard C, Burger U, Haas D and Defago G 1990 Pseudomonads as antagonists of plant pathogens in the rhizosphere: Role of the antibiotic 2,4 diacetylphloroglucinol in the suppression of black root rot of tobacco. Symbiosis 9, 327–341.
Keel C, Schnider U, Maurhofer M, Voisard C, Laville J, Burger U, Wirthner P, Haas D and Defago G 1992 Suppression of root diseases by Pseudomonas fluorescens CHAO: Importance of the bacterial secondary metabolite 2,4-diacetylphloroglucinol. Mol. Plant-Microbe Interact. 5, 4–13.
Kloepper J W, Leong J, Teintze M and Scroth M N 1980 Enhanced plant growth by siderophores produced by plant growth-promoting rhizobacteria. Nature (Londen) 286, 885–886.
Kloepper J W and Scroth M N 1981 Relationship of in vitro antibiosis of plant growth-promoting rhizobacteria to plant growth and the displacement of root microflora. Phytopathology 71, 1020–1024.
Kraus J and Loper J E 1992 Lack of evidence for a role of antifungal metabolite production by Pseudomonas fluorescens PF-5 in biological control of Pythium damping-off of cucumber. Phytopathology 82, 264–271.
Lam B S, Strobel G A, Harrison L A and Lam S R 1987 Transposon mutagenesis and tagging of a fluorescent Pseudomonas: antimycotic production is necessary for control of Dutch Elm disease. Proc. Natl. Acad. Sci. USA 84, 6447–6451.
Thomashow L S and Weller D M 1988 Role of a phenazine antibiotic from Pseudomonas fluorescens in biological control of Gaeumannomyces graminis var tritici. J. Bacteriol. 170, 3499–3508.
Thomashow L S, Weller D M, Bonsal R F and Pierson L SIII 1990 Production of the antibiotic phenazine-1-carboxylic acid by fluorescent Pseudomonas species in the rhizosphere of wheat. Appl. Environ. Microbiol. 56, 908–912.
Thomashow L S and Weller D M 1990 Application of fluorescent Pseudomonads to control root disease of wheat and some mechanisms of disease suppression. In Biological Control of Soil-Borne Pathogens. Ed. D Hornby. pp 109–122.
Tuzun S and Kloepper J 1994 Induced systemic resistance by plant growth-promoting rhizobacteria. Proc. Third Int. Workshop, PGPR, Adelaide. pp 104–109.
Vincent M N, Harrison L A, Brackin J M, Kovacevich P A, Mukerji P, Weller D M and Pierson E A 1991 Genetic analysis of the antifungal activity of a soilborne Pseudomonas aurefaciens strain. Appl. Environ. Microbiol. 57, 2928–2934.
Weller D M and Cook R J 1983 Suppression of take-all of wheat by seed treatments with fluorescent Pseudomonads. Phytopathology 73, 463–469.
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Carruthers, F.L., Shum-Thomas, T., Conner, A.J. et al. The significance of antibiotic production by Pseudomonas aureofaciens PA 147-2 for biological control of Phytophthora megasperma root rot of asparagus. Plant Soil 170, 339–344 (1995). https://doi.org/10.1007/BF00010487
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DOI: https://doi.org/10.1007/BF00010487