This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Balaji, B.
Right arrow Articles by Csonka, L. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Balaji, B.
Right arrow Articles by Csonka, L. N.
Agricola
Right arrow Articles by Balaji, B.
Right arrow Articles by Csonka, L. N.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, December 2005, p. 8273-8283, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.8273-8283.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Timing of Induction of Osmotically Controlled Genes in Salmonella enterica Serovar Typhimurium, Determined with Quantitative Real-Time Reverse Transcription-PCR

Boovaraghan Balaji,1,{dagger} Kathleen O'Connor,2 Jeffrey R. Lucas,2 Joseph M. Anderson,1,3 and Laszlo N. Csonka2*

Department of Agronomy,1 Department of Biological Sciences,2 USDA-ARS, Purdue University, West Lafayette, Indiana 479073

Received 17 May 2005/ Accepted 6 September 2005

The signals that control the transcription of osmoregulated genes are not understood satisfactorily. The "turgor control model" suggested that the primary osmoregulatory signal in Enterobacteriaceae is turgor loss, which induces the kdp K+ transport operon and activates the Trk K+ permease. The ensuing increase in cytoplasmic K+ concentration was proposed to be the signal that turns on all secondary responses, including the induction of the proU (proline-glycine betaine transport) operon. The "ionic strength model" proposed that the regulatory signal for all osmotically controlled responses is the increase in the cytoplasmic ionic strength or macromolecular crowding after an osmotic upshift. The assumption in the turgor control model that the induction of kdp is a primary response to osmotic shock predicts that this response should precede all secondary responses. Both models predict that the induction of all osmotically activated responses should be independent of the chemical nature of the solute used to impose osmotic stress. We tested these predictions by quantitative real-time reverse transcription-PCR analysis of the expression of six osmotically regulated genes in Salmonella enterica serovar Typhimurium. After shock with 0.3 M NaCl, proU was induced at 4 min, proP and rpoS were induced at 4 to 6 min, kdp was induced at 8 to 9 min, and otsB and ompC were induced at 10 to 12 min. After an equivalent osmotic shock with 0.6 M sucrose, proU was induced with kinetics similar to those seen with NaCl, but induction of kdp was reduced 150-fold in comparison to induction by NaCl. Our results are inconsistent with both the turgor control and the ionic strength control models.

* Corresponding author. Mailing address: Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392. Phone: (765) 494-4969. Fax: (765) 496-1496. E-mail: lcsonka{at}bilbo.bio.purdue.edu.

{dagger} Present address: Department of Plant Microbiology and Pathology, 108 Waters, University of Missouri, Columbia, MO 65211.

Applied and Environmental Microbiology, December 2005, p. 8273-8283, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.8273-8283.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Pan, Z., Carter, B., Nunez-Garcia, J., AbuOun, M., Fookes, M., Ivens, A., Woodward, M. J., Anjum, M. F. (2009). Identification of genetic and phenotypic differences associated with prevalent and non-prevalent Salmonella Enteritidis phage types: analysis of variation in amino acid transport. Microbiology 155: 3200-3213 [Abstract] [Full Text]  
  • Dominguez-Ferreras, A., Munoz, S., Olivares, J., Soto, M. J., Sanjuan, J. (2009). Role of Potassium Uptake Systems in Sinorhizobium meliloti Osmoadaptation and Symbiotic Performance. J. Bacteriol. 191: 2133-2143 [Abstract] [Full Text]  
  • Chiu, S.-W., Chen, S.-Y., Wong, H.-c. (2008). Localization and Expression of MreB in Vibrio parahaemolyticus under Different Stresses. Appl. Environ. Microbiol. 74: 7016-7022 [Abstract] [Full Text]  
  • Gunasekera, T. S., Csonka, L. N., Paliy, O. (2008). Genome-Wide Transcriptional Responses of Escherichia coli K-12 to Continuous Osmotic and Heat Stresses. J. Bacteriol. 190: 3712-3720 [Abstract] [Full Text]  
  • Zimmann, P., Steinbrugge, A., Schniederberend, M., Jung, K., Altendorf, K. (2007). The Extension of the Fourth Transmembrane Helix of the Sensor Kinase KdpD of Escherichia coli Is Involved in Sensing. J. Bacteriol. 189: 7326-7334 [Abstract] [Full Text]  
  • Golby, P., Hatch, K. A., Bacon, J., Cooney, R., Riley, P., Allnutt, J., Hinds, J., Nunez, J., Marsh, P. D., Hewinson, R. G., Gordon, S. V. (2007). Comparative transcriptomics reveals key gene expression differences between the human and bovine pathogens of the Mycobacterium tuberculosis complex. Microbiology 153: 3323-3336 [Abstract] [Full Text]  
  • McMeechan, A., Roberts, M., Cogan, T. A., Jorgensen, F., Stevenson, A., Lewis, C., Rowley, G., Humphrey, T. J. (2007). Role of the alternative sigma factors {sigma}E and {sigma}S in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock. Microbiology 153: 263-269 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»