Plant Molecular Biology

, Volume 43, Issue 4, pp 515–525

Characterisation of two distinct HKT1-like potassium transporters from Eucalyptus camaldulensis

  • David J. Fairbairn
  • Weihong Liu
  • Daniel P. Schachtman
  • Sara Gomez-Gallego
  • Sharon R. Day
  • Robert D. Teasdale
Article

DOI: 10.1023/A:1006496402463

Cite this article as:
Fairbairn, D.J., Liu, W., Schachtman, D.P. et al. Plant Mol Biol (2000) 43: 515. doi:10.1023/A:1006496402463

Abstract

Potassium is an essential macronutrient in higher plants. It plays an important physiological role in stoma movements, osmoregulation, enzyme activation and cell expansion. The demand for potassium can be substantial, especially when the plant concerned is a Eucalyptus tree in excess of 50 m tall. We have isolated two cDNAs, EcHKT1 and EcHKT2, from Eucalyptus camaldulensis (river red gum) which are expressed in leaves, stems and roots. These encode potassium transporter polypeptides with homology to the wheat K+-Na+ symporter, HKT1. EcHKT1 and EcHKT2 both complemented the K+-limited growth of an Escherichia coli K+-uptake-deficient triple mutant. EcHKT1 and EcHKT2also mediated Na+ and K+ uptake when expressed in Xenopus oocytes. A comparison of the EcHKT1 and EcHKT2 sequences and their transport properties indicated that these cDNAs represent two K+ transporters with distinct functional characteristics. The functional and structural conservation between these two E. camaldulensis genes and the wheat HKT1 suggests that they play an important, albeit elusive, physiological role.

complementation electrophysiology Eucalyptus camaldulensis potassium transport salinity 

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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • David J. Fairbairn
    • 1
    • 2
  • Weihong Liu
    • 3
  • Daniel P. Schachtman
    • 3
  • Sara Gomez-Gallego
    • 1
    • 4
  • Sharon R. Day
    • 1
    • 5
  • Robert D. Teasdale
    • 1
  1. 1.ForBio Research Pty LtdMiltonAustralia
  2. 2.Department of BotanyUniversity of QueenslandBrisbaneAustralia
  3. 3.CSIRO Plant IndustryGlen OsmondAustralia
  4. 4.GADI Research CentreUniversity of CanberraCanberraAustralia
  5. 5.Department of Veterinary Microbiology and Parasitology, School of Veterinary MedicineLouisiana State UniversityUSA

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