Physiological and transcriptomic characterization of a fliA mutant of Pseudomonas putida KT2440
2010 (English)In: Environmental Microbiology Reports, ISSN 1758-2229, Vol. 2, no 3, 373-380 p.Article in journal (Refereed) Published
Pseudomonas putida KT2440 encodes 23 alternative sigma factors. The fliA gene, which encodes sigma 28, is in a cluster with other genes involved in flagella biosynthesis and chemotaxis. Reverse transcriptase-PCR revealed that this cluster is comprised of four independent transcriptional units: flhAF, fleNfliA, cheYZA and cheBmotAB. We generated a nonpolar fliA mutant by homologous recombination and tested its motility, adhesion to biotic and abiotic surfaces, and responses to various stress conditions. The mutant strain was nonmotile and exhibited decreased capacity to bind to corn seeds, although its ability to colonize the rhizosphere of plants was unaffected. The mutant was also affected in binding to abiotic surfaces and its ability to form biofilms decreased by almost threefold. In the fliA mutant background expression of 25 genes was affected: two genes were upregulated and 23 genes were downregulated. In addition to a number of motility and chemotaxis genes, the fliA gene product is also necessary for the expression of some genes potentially involved in amino acid utilization or stress responses; however, we were unable to assign specific phenotypes linked to these genes since the fliA mutant used the same range of amino acids as the parental strain, and was as tolerant as the wild type to stress imposed by heat, antibiotics, NaCl, sodium dodecyl sulfate, H2O2 and benzoate. Based on the sequence alignment of promoters recognized by FliA and genome in silico analysis, we propose that P. putida sigma 28 recognizes a TCAAG-t-N-12-GCCGATA consensus sequence located between -34 and -8 and that this sequence is preferentially associated with an AT-rich upstream region.
Place, publisher, year, edition, pages
2010. Vol. 2, no 3, 373-380 p.
cleavage pathway operon; escherichia-coli; promoter recognition; mutational analysis; positive regulator; secretion system; dna microarray; rna-polymerase; flagellar; motility
IdentifiersURN: urn:nbn:se:umu:diva-43194DOI: 10.1111/j.1758-2229.2009.00084.xISI: 000279404300003OAI: oai:DiVA.org:umu-43194DiVA: diva2:412375
ISI Document Delivery No.: 619BU Times Cited: 0 Cited Reference Count: 41 Juan Rodriguez-Herva, Jose Duque, Estrella Antonia Molina-Henares, Maria Navarro-Aviles, Gloria van Dillewijn, Pieter de la Torre, Jesus Molina-Henares, Antonio J. Sanchez-de la Campa, Ana Ann Ran, F. Segura, Ana Shingler, Victoria Ramos, Juan-Luis ERA-NET [GEN2006-27750-C5-5-E/SYS]; CONSOLIDER-INGENIO [CSD2007-00005]; Junta de Andalucia [CIV-3010] This study was supported by the following grants: ERA-NET (GEN2006-27750-C5-5-E/SYS), CONSOLIDER-INGENIO (CSD2007-00005) and CIV-3010 from Junta de Andalucia. We thank A. Hurtado for DNA sequencing, M.M. Fandila and C. Lorente for secretarial assistance, and K. Shashok and B. Pakuts for improving the use of English in the manuscript. Wiley-blackwell publishing, inc Malden2011-04-222011-04-222011-10-11Bibliographically approved