Campus Units
Plant Pathology and Microbiology
Document Type
Article
Publication Version
Published Version
Publication Date
4-2008
Journal or Book Title
Journal of Bacteriology
Volume
190
Issue
8
First Page
2717
Last Page
2725
DOI
10.1128/JB.01585-07
Abstract
The plant pathogen Pseudomonas syringae derives better osmoprotection from choline than from glycine betaine, unlike most bacteria that have been characterized. In this report, we identified a betaine/carnitine/choline family transporter (BCCT) in P. syringae pv. tomato strain DC3000 that mediates the transport of choline and acetylcholine. This transporter has a particularly low affinity (Km of 876 μM) and high capacity (Vmax of 80 nmol/min/mg of protein) for choline transport relative to other known BCCTs. Although BetT activity increased in response to hyperosmolarity, BetT mediated significant uptake under low-osmolarity conditions, suggesting a role in transport for both osmoprotection and catabolism. Growth studies with mutants deficient in BetT and other choline transporters demonstrated that BetT was responsible for the superior osmoprotection conferred to P. syringae by choline over glycine betaine when these compounds were provided at high concentrations (>100 μM). These results suggest that P. syringae has evolved to survive in relatively choline-rich habitats, a prediction that is supported by the common association of P. syringae with plants and the widespread production of choline, but genus- and species-specific production of glycine betaine, by plants. Among the three putative BCCT family transporters in Pseudomonas aeruginosa and six in Pseudomonas putida, different transporters were predicted to function based on similarity to Escherichia coli BetT than to P. syringae BetT. Functional P. putida and P. aeruginosa transporters were identified, and their possession of a long C-terminal tail suggested an osmoregulatory function for this tail; this function was confirmed for P. syringaeBetT using deletion derivatives.
Copyright Owner
American Society for Microbiology
Copyright Date
2008
Language
en
File Format
application/pdf
Recommended Citation
Chen, Chiliang and Beattie, Gwyn A., "Pseudomonas syringae BetT Is a Low-Affinity Choline Transporter That Is Responsible for Superior Osmoprotection by Choline over Glycine Betaine" (2008). Plant Pathology and Microbiology Publications. 97.
https://lib.dr.iastate.edu/plantpath_pubs/97
Included in
Agricultural Science Commons, Agriculture Commons, Plant Biology Commons, Plant Breeding and Genetics Commons, Plant Pathology Commons
Comments
This article is from Journal of Bacteriology 190 (2008): 2717, doi: 10.1128/JB.01585-07. Posted with permission.