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. 1997 Dec;9(12):2281–2289. doi: 10.1105/tpc.9.12.2281

The HAK1 gene of barley is a member of a large gene family and encodes a high-affinity potassium transporter.

G E Santa-María 1, F Rubio 1, J Dubcovsky 1, A Rodríguez-Navarro 1
PMCID: PMC157074  PMID: 9437867

Abstract

The high-affinity K+ uptake system of plants plays a crucial role in nutrition and has been the subject of extensive kinetic studies. However, major components of this system remain to be identified. We isolated a cDNA from barley roots, HvHAK1, whose translated sequence shows homology to the Escherichia coli Kup and Schwanniomyces occidentalis HAK1 K+ transporters. HvHAK1 conferred high-affinity K+ uptake to a K(+)-uptake-deficient yeast mutant exhibiting the hallmark characteristics of the high-affinity K+ uptake described for barley roots. HvHAK1 also mediated low-affinity Na+ uptake. Another cDNA (HvHAK2) encoding a polypeptide 42% identical to HvHAK1 was also isolated. Analysis of several genomes of Triticeae indicates that HvHAK1 belongs to a multigene family. Translated sequences from bacterial DNAs and Arabidopsis, rice, and possibly human cDNAs show homology to the Kup-HAK1-HvHAK1 family of K+ transporters.

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Selected References

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  1. Anderson J. A., Best L. A., Gaber R. F. Structural and functional conservation between the high-affinity K+ transporters of Saccharomyces uvarum and Saccharomyces cerevisiae. Gene. 1991 Mar 1;99(1):39–46. doi: 10.1016/0378-1119(91)90031-6. [DOI] [PubMed] [Google Scholar]
  2. Anderson J. A., Huprikar S. S., Kochian L. V., Lucas W. J., Gaber R. F. Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1992 May 1;89(9):3736–3740. doi: 10.1073/pnas.89.9.3736. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bañuelos M. A., Klein R. D., Alexander-Bowman S. J., Rodríguez-Navarro A. A potassium transporter of the yeast Schwanniomyces occidentalis homologous to the Kup system of Escherichia coli has a high concentrative capacity. EMBO J. 1995 Jul 3;14(13):3021–3027. doi: 10.1002/j.1460-2075.1995.tb07304.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Brunelli J. P., Pall M. L. A series of yeast/Escherichia coli lambda expression vectors designed for directional cloning of cDNAs and cre/lox-mediated plasmid excision. Yeast. 1993 Dec;9(12):1309–1318. doi: 10.1002/yea.320091204. [DOI] [PubMed] [Google Scholar]
  5. Cao Y., Ward J. M., Kelly W. B., Ichida A. M., Gaber R. F., Anderson J. A., Uozumi N., Schroeder J. I., Crawford N. M. Multiple genes, tissue specificity, and expression-dependent modulationcontribute to the functional diversity of potassium channels in Arabidopsis thaliana. Plant Physiol. 1995 Nov;109(3):1093–1106. doi: 10.1104/pp.109.3.1093. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dubcovsky J., Luo M. C., Zhong G. Y., Bransteitter R., Desai A., Kilian A., Kleinhofs A., Dvorák J. Genetic map of diploid wheat, Triticum monococcum L., and its comparison with maps of Hordeum vulgare L. Genetics. 1996 Jun;143(2):983–999. doi: 10.1093/genetics/143.2.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Epstein E., Rains D. W., Elzam O. E. RESOLUTION OF DUAL MECHANISMS OF POTASSIUM ABSORPTION BY BARLEY ROOTS. Proc Natl Acad Sci U S A. 1963 May;49(5):684–692. doi: 10.1073/pnas.49.5.684. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gaber R. F., Styles C. A., Fink G. R. TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae. Mol Cell Biol. 1988 Jul;8(7):2848–2859. doi: 10.1128/mcb.8.7.2848. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Gassman W., Rubio F., Schroeder J. I. Alkali cation selectivity of the wheat root high-affinity potassium transporter HKT1. Plant J. 1996 Nov;10(5):869–852. doi: 10.1046/j.1365-313x.1996.10050869.x. [DOI] [PubMed] [Google Scholar]
  10. Huang Z. Z., Yan X., Jalil A., Norlyn J. D., Epstein E. Short-term experiments on ion transport by seedlings and excised roots : technique and validity. Plant Physiol. 1992 Dec;100(4):1914–1920. doi: 10.1104/pp.100.4.1914. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Ketchum K. A., Slayman C. W. Isolation of an ion channel gene from Arabidopsis thaliana using the H5 signature sequence from voltage-dependent K+ channels. FEBS Lett. 1996 Jan 2;378(1):19–26. doi: 10.1016/0014-5793(95)01417-9. [DOI] [PubMed] [Google Scholar]
  12. Ko C. H., Gaber R. F. TRK1 and TRK2 encode structurally related K+ transporters in Saccharomyces cerevisiae. Mol Cell Biol. 1991 Aug;11(8):4266–4273. doi: 10.1128/mcb.11.8.4266. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kochian L. V., Lucas W. J. Potassium transport in corn roots : I. Resolution of kinetics into a saturable and linear component. Plant Physiol. 1982 Dec;70(6):1723–1731. doi: 10.1104/pp.70.6.1723. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Lagarde D., Basset M., Lepetit M., Conejero G., Gaymard F., Astruc S., Grignon C. Tissue-specific expression of Arabidopsis AKT1 gene is consistent with a role in K+ nutrition. Plant J. 1996 Feb;9(2):195–203. doi: 10.1046/j.1365-313x.1996.09020195.x. [DOI] [PubMed] [Google Scholar]
  15. Maathuis F. J., Sanders D. Mechanism of high-affinity potassium uptake in roots of Arabidopsis thaliana. Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9272–9276. doi: 10.1073/pnas.91.20.9272. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Maathuis FJM., Verlin D., Smith F. A., Sanders D., Fernandez J. A., Walker N. A. The Physiological Relevance of Na+-Coupled K+-Transport. Plant Physiol. 1996 Dec;112(4):1609–1616. doi: 10.1104/pp.112.4.1609. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Müller-Röber B., Ellenberg J., Provart N., Willmitzer L., Busch H., Becker D., Dietrich P., Hoth S., Hedrich R. Cloning and electrophysiological analysis of KST1, an inward rectifying K+ channel expressed in potato guard cells. EMBO J. 1995 Jun 1;14(11):2409–2416. doi: 10.1002/j.1460-2075.1995.tb07238.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Rains D. W., Epstein E. Sodium absorption by barley roots: role of the dual mechanisms of alkali cation transport. Plant Physiol. 1967 Mar;42(3):314–318. doi: 10.1104/pp.42.3.314. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Rains D. W., Epstein E. Transport of Sodium in Plant Tissue. Science. 1965 Jun 18;148(3677):1611–1611. doi: 10.1126/science.148.3677.1611. [DOI] [PubMed] [Google Scholar]
  20. Ramos J., Alijo R., Haro R., Rodriguez-Navarro A. TRK2 is not a low-affinity potassium transporter in Saccharomyces cerevisiae. J Bacteriol. 1994 Jan;176(1):249–252. doi: 10.1128/jb.176.1.249-252.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Rubio F., Gassmann W., Schroeder J. I. Response: high-affinity potassium uptake in plants. Science. 1996 Aug 16;273(5277):978–979. doi: 10.1126/science.273.5277.978. [DOI] [PubMed] [Google Scholar]
  22. Rubio F., Gassmann W., Schroeder J. I. Sodium-driven potassium uptake by the plant potassium transporter HKT1 and mutations conferring salt tolerance. Science. 1995 Dec 8;270(5242):1660–1663. doi: 10.1126/science.270.5242.1660. [DOI] [PubMed] [Google Scholar]
  23. Schachtman D. P., Schroeder J. I. Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plants. Nature. 1994 Aug 25;370(6491):655–658. doi: 10.1038/370655a0. [DOI] [PubMed] [Google Scholar]
  24. Soldatenkov V. A., Velasco J. A., Avila M. A., Dritschilo A., Notario V. Isolation and characterization of SpTRK, a gene from Schizosaccharomyces pombe predicted to encode a K+ transporter protein. Gene. 1995 Aug 8;161(1):97–101. doi: 10.1016/0378-1119(95)00274-a. [DOI] [PubMed] [Google Scholar]
  25. Walker N. A., Sanders D., Maathuis F. J. High-affinity potassium uptake in plants. Science. 1996 Aug 16;273(5277):977–979. doi: 10.1126/science.273.5277.977. [DOI] [PubMed] [Google Scholar]
  26. Welch R. M., Epstein E. The dual mechanisms of alkali cation absorption by plant cells: their parallel operation across the plasmalemma. Proc Natl Acad Sci U S A. 1968 Oct;61(2):447–453. doi: 10.1073/pnas.61.2.447. [DOI] [PMC free article] [PubMed] [Google Scholar]

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