title: Rice plants expressing the moss sodium pumping ATPase PpENA1 maintain greater biomass production under salt stress.
abstract: High cytosolic concentrations of Na+ inhibit plant growth and development. To maintain low cytosolic concentrations of Na+ , higher plants use membrane-bound transporters that drive the efflux of Na+ or partition Na+ ions from the cytosol, either to the extracellular compartment or into the vacuole. Bryophytes also use an energy-dependent Na+ pumping ATPase, not found in higher plants, to efflux Na+ . To investigate whether this transporter can increase the salt tolerance of crop plants, Oryza sativa has been transformed with the Physcomitrella patens Na+ pumping ATPase (PpENA1). When grown in solutions containing 50 mm NaCl, plants constitutively expressing the PpENA1 gene are more salt tolerant and produce greater biomass than controls. Transgenics and controls accumulate similar amounts of Na+ in leaf and root tissues under stress, which indicates that the observed tolerance is not because of Na+ exclusion. Moreover, inductively coupled plasma analysis reveals that the concentration of other ions in the transformants and the controls is similar. The transgenic lines are developmentally normal and fertile, and the transgene expression levels remain stable in subsequent generations. GFP reporter fusions, which do not alter the ability of PpENA1 to complement a salt-sensitive yeast mutant, indicate that when it is expressed in plant tissues, the PpENA1 protein is located in the plasma membrane. PpENA1 peptides are found in plasma membrane fractions supporting the plasma membrane targeting. The results of this study demonstrate the utility of PpENA1 as a potential tool for engineering salinity tolerance in important crop species.
authors.affiliation: Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, Australia. andrew.jacobs@acpfg.com.au
authors.forename: Andrew
authors.initials: A
authors.lastname: Jacobs
authors.forename: Kristina
authors.initials: K
authors.lastname: Ford
authors.forename: Jodie
authors.initials: J
authors.lastname: Kretschmer
authors.forename: Mark
authors.initials: M
authors.lastname: Tester
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers; D019068:Bryopsida / Q000201:enzymology / Q000235:genetics; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods; D003001:Cloning, Molecular; D017343:Genes, Plant; D019697:Onions / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D010783:Photometry / Q000379:methods; D059828:Plant Cells / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological; D019076:Transgenes
chemical_list: D015415:Biomarkers; D027682:Cation Transport Proteins; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D012964:Sodium; D000251:Adenosine Triphosphatases; C021838:sodium-translocating ATPase