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Article
Construction and Characterization of a proU-gfp Transcriptional Fusion That Measures Water Availability in a Microbial Habitat
Applied and Environmental Microbiology
  • Catherine A. Axtell, Iowa State University
  • Gwyn A. Beattie, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
9-1-2002
DOI
10.1128/AEM.68.9.4604–4612.2002
Abstract
We constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. This fusion between the proU promoter from Escherichia coli and the reporter gene gfp was introduced into strains of E. coli, Pantoea agglomerans, and Pseudomonas syringae. The proU-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of NaCl, Na2SO4, KCl, or polyethylene glycol (molecular weight, 8000). The fusion was induced to a detectable level by NaCl concentrations of as low as 10 mM in all three bacterial species. Water deprivation induced proU-gfp expression in both planktonic and surface-associated cells; however, it induced a higher level of expression in the surface-associated cells. Following the introduction of P. agglomerans biosensor cells onto bean leaves, the cells detected a significant decrease in water availability within only 5 min. After 30 min, the populations were exposed, on average, to a water potential equivalent to that imposed by approximately 55 mM NaCl. These results demonstrate the effectiveness of a proU-gfp-based biosensor for evaluating water availability on leaves. Furthermore, the inducibility of proU-gfp in multiple bacterial species illustrates the potential for tailoring proU-gfp-based biosensors to specific habitats.
Comments

This is an article from Applied and Environmental Microbiology 68 (2002): 4604, doi: 10.1128/AEM.68.9.4604–4612.2002. Posted with permission.

Copyright Owner
American Society for Microbiology
Language
en
File Format
application/pdf
Citation Information
Catherine A. Axtell and Gwyn A. Beattie. "Construction and Characterization of a proU-gfp Transcriptional Fusion That Measures Water Availability in a Microbial Habitat" Applied and Environmental Microbiology Vol. 68 Iss. 9 (2002) p. 4604 - 4612
Available at: http://works.bepress.com/gwyn-beattie/17/