title: Potassium and sodium transporters of Pseudomonas aeruginosa regulate virulence to barley.
abstract: We investigated the role of three uncharacterized cation transporters of Pseudomonas aeruginosa PAO1 as virulence factors for barley: PA1207, PA5021, and PA2647. PAO1 displayed reduced barley virulence with inactivated PA1207, PA5021, and PA2647 as well as with one known Na(+)/H(+) antiporter, PA1820. Using the Escherichia coli LB2003 mutant lacking three K(+) uptake systems, the expression of the PA5021 gene repressed LB2003 growth with low K(+), but the strain acquired tolerance to high K(+). In contrast, the expression of the PA1207 gene enhanced growth of LB2003 with low K(+) but repressed its growth with high K(+); therefore, the PA5021 protein exports K(+), while the PA1207 protein imports K(+). The PA5021 mutant of P. aeruginosa also showed impaired growth at 400 mM KCl and at 400 mM NaCl; therefore, the PA5021 protein may also export Na(+). The loss of the PA5021 protein also decreased production of the virulence factor pyocyanin; corroborating this result, pyocyanin production decreased in wild-type PAO1 under high salinity. Whole-genome transcriptome analysis showed that PAO1 induced more genes in barley upon infection compared to the PA5021 mutant. Additionally, PAO1 infection induced water stress-related genes in barley, which suggests that barley may undergo water deficit upon infection by this pathogen.
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ueda
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D001467:Hordeum / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D011710:Pyocyanine / Q000235:genetics / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D010940:Plant Proteins; D037521:Virulence Factors; D012964:Sodium; D011710:Pyocyanine; D011188:Potassium