Cloning of genes involved in the synthesis of pyrrolnitrin from Pseudomonas fluorescens and role of pyrrolnitrin synthesis in biological control of plant disease

• Published in: Applied and Environmental Microbiology Vol. 60; no. 1; pp. 78 - 85
• Main Authors: Hill, D.S, Stein, J.I, Torkewitz, N.R, Morse, A.M, Howell, C.R, Pachlatko, J.P, Becker, J.O, Ligon, J.M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.01.1994
• Subjects: Agronomy. Soil science and plant productions; ANTIBIOTICOS; ANTIBIOTIQUE; Bacteria; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; BIOSINTESIS; BIOSYNTHESE; Biotechnology; Botany; CLONACION; CLONAGE; CONTROL BIOLOGICO; Cotton; Disease; FONGICIDE; Fundamental and applied biological sciences. Psychology; Fungi; FUNGICIDAS; GENE; GENES; GOSSYPIUM HIRSUTUM; LUTTE BIOLOGIQUE; Microorganism-Plant Interactions; Miscellaneous; Mission oriented research; MUTANT; MUTANTES; PESTICIDE MICROBIEN; PLAGUICIDAS MICROBIANOS; PROPIEDADES ANTIMICOSICAS; PROPRIETE ANTIFONGIQUE; PSEUDOMONAS FLUORESCENS; RHIZOCTONIA; Rhizoctonia solani; Malvaceae; Pseudomonadales; Plant pathogen; Biological control; Biosynthesis; Pseudomonas fluorescens; Fiber crop; Pyrrole derivatives; Fungi; Gene; Dicotyledones; Angiospermae; Bacteria; Pseudomonadaceae; Rhizoctonia solani; Spermatophyta; Gossypium hirsutum; Fungi Imperfecti; Antagonist; Mutation; Molecular cloning; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.60.1.78-85.1994

A soil isolate of Pseudomonas fluorescens (BL915) was shown to be an effective antagonist of Rhizoctonia solani-induced damping-off of cotton. Investigation of the biological basis of this antagonism revealed that the strain produces pyrrolnitrin, a secondary metabolite known to inhibit R. solani and other fungi. Mutants of strain BL915 that did not produce pyrrolnitrin and did not suppress damping-off of cotton by R. solani were generated by exposure to N-methyl-N'-nitro-N-nitrosoguanidine. A gene region that was capable of restoring pyrrolnitrin production to the non-pyrrolnitrin-producing mutants and of conferring this ability upon two other P. fluorescens strains not otherwise known to produce this compound or to be capable of suppressing damping-off caused by R. solani was isolated from strain BL915. The non-pyrrolnitrin-producing strains (mutants of BL915 and the other two P. fluorescens strains) which synthesized pyrrolnitrin after the introduction of the gene region from strain BL915 were also shown to be equal to strain BL915 in their ability to suppress R. solani-induced damping-off of cotton. These results indicate that we have isolated from P. fluorescens BL915 a gene(s) that has a role in the synthesis of pyrrolnitrin and that the production of this compound has a role in the ability of this strain to control damping-off of cotton by R. solani