[Transposon tnPhoA mutagenesis as a method of obtaining mutants of Azospirillum brasilense by motility and flagellation].
Three A. brasilense strains (S27, SpBr14, and KR77) did not hydrolyze the chromogenic substrate of alkaline phosphatase (PhoA), X-phosphate, in situ, and were used as recipients in experiments on TnphoA mutagenesis. KMR transconjugates were obtained only for A. brasilense S27, 85% of them were also PhoA+. About 12% TnphoA mutants of A. brasilense S27 had reduces capacity to swarming and 3% of mutants neither swam nor swarmed. These totally immotile clones were examined under transmission electron microscope and were classified as Fla-Laf-, Fla-leakyLaf-, and Fla-Laf+ mutants. In Fla-Laf+ TnphoA mutants of S27, the expression of their lateral flagella (Laf) retained the wild-type inducibility. The presence of intact polar flagellum (Fla) did not seem to be obligatory for controllable expression of Laf in A. brasilense S27. The data suggest that A. brasilense S27 Fla and Laf systems have common structural and/or regulatory components. The PhoA+ phenotype of S27 Fla- mutants suggested a periplasmic and/or membrane localization of the hybrid proteins, the formation of which blocks the flagellar assembly or functioning. Immunochemical analysis with antibodies to alkaline phosphatase will identify these proteins.
Katsy
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EI
Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia.
Shelud'ko
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AV
D000469:Alkaline Phosphatase / Q000235:genetics* / Q000276:immunology; D000907:Antibodies, Bacterial / Q000276:immunology; D015806:Azospirillum brasilense / Q000201:enzymology / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D004251:DNA Transposable Elements; D008854:Microscopy, Electron; D016296:Mutagenesis; D010641:Phenotype
D000907:Antibodies, Bacterial; D004251:DNA Transposable Elements; D000469:Alkaline Phosphatase