Abstract
To understand the mechanism of ion homeostasis in salt tolerant and sensitive plants, we isolated cDNAs for K+ transporter PhaHAK1-u and PhaHAK5-u from reed plants. PhaHAK1-u belongs to group I and PhaHAK5-u belongs to group IV by phylogenetic analysis, respectively. PhaHAK5-u is predicted to be a plasma membrane transporter, and shows high-affinity K+ transporter. Expression of PhaHAK5 was found in salt-sensitive reed plants, but not in any parts of salt-tolerant reed plants maintained under both control and K+ starvation conditions. Under the NaCl stress, the K+ uptake ability of the yeast strain expressing PhaHAK5-u was remarkably lower than that of the yeast strain expressing PhaHAK1-u, and PhaHAK5-u showed Na+ permeability. These results suggest that PhaHAK5 is one of the routes by which Na+ enters cells.
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References
Banuelos MA, Klein RD, Alexander-Bowman SJ, Rodriguez-Navarro A (1995) A potassium transporter of the yeast Schwanniomyces occidentalis homologous to the Kup system of Escherichia coli has a high concentrative capacity. EMBO J 14:3021–3027
Banuelos MA, Garciadeblas B, Cubero B, Rodriguez-Navarro A (2002) Inventory and functional characterization of the HAK potassium transporters of rice. Plant Physiol 130:784–795
Flowers TJ, Garcia A, Koyama M, Yeo AR (1997) Breeding for salt tolerance in crop plants—the role of molecular biology. Acta Physiol Plant 19:427–433
Fu HH, Luan S (1998) AtKUP1: A dual-affinity K+ transporter from Arabidopsis. Plant Cell 10:63–73
Garciadeblas B, Benito B, Rodriguez-Navarro A (2002) Molecular cloning and functional expression in bacteria of the potassium transporters CnHAK1 and CnHAK2 of the seagrass Cymodocea nodosa. Plant Mol Biol 50:623–633
Golldack D, Su H, Quigley F, Kamasani UR, Munoz-Garay C, Balderas E, Bennett J, Bohnert HJ, Pantoja O (2002) Characterization of a HKT-type transporter in rice as a general alkali cation transporter. Plant J 31:529–542
Horie T, Yoshida K, Nakayama H, Yamada K, Oiki S, Shinmyo A (2001) Two types of HKT transporters with different properties of Na+ and K+ transport in Oryza sativa. Plant J 27:129–138
Kim EJ, Kwak JM, Uozumi N, Schroeder JI (1998) AtKUP1: An Arabidopsis gene encoding high-affinity potassium transport activity. Plant Cell 10:51–62
Martinez-Cordero MA, Martinez V, Rubio F (2004) Cloning and functional characterization of the high-affinity K+ transporter HAK1 of pepper. Plant Mol Biol 56:413–421
Maser P, Gierth M, Schroeder JI (2002) Molecular mechanisms of potassium and sodium uptake in plants. Plant Soil 247:43–54
Mori M, Miyamura H, Watanabe K, Ohtani H (2000) Transformation of Phragmites australis mediated by Agrobacterium tumefaciens. Breed Res 2 Suppl 2:106
Quintero FJ, Blatt MR (1997) A new family of K+ transporters from Arabidopsis that are conserved across phyla. FEBS Lett 415:206–211
Ren Z-H, Gao J-P, Li L-G, Cai X-L, Huang W, Chao D-Y, Zhu M-Z, Wang Z-Y, Luan S, Lin H-X (2005) A rice quantitative trait locus for salt tolerance encodes a sodium transporter. Nat Gen 37:1141–1146
Rodriguez-Navarro A (2000) Potassium transport in fungi and plants. Biochem Biophys Acta 1469:1–30
Rubio F, Schwarz M, Gassmann W, Schroeder JI (1999) Genetic selection of mutations in the high affinity K+ transporter HKT1 that define functions of a loop site for reduced Na+ permeability and increased Na+ tolerance. J Biol Chem 274:6839–6847
Rubio F, Santa-Maria GE, Rodriguez-Navarro A (2000) Cloning of Arabidopsis and barley cDNAs encoding HAK potassium transporters in root and shoot cells. Physiol Plant 109:34–43
Santa-Maria GE, Rubio F, Dubcovsky J, Rodriguez-Navarro A (1997) The HAK1 gene of barley is a member of a large gene family and encodes a high-affinity potassium transporter. Plant Cell 9:2281–2289
Schachtman DP, Liu W (1999) Molecular pieces to the puzzle of the interaction between potassium and sodium uptake in plants. Trends Plant Sci 4:281–287
Schleyer M, Bakker EP (1993) Nucleotide sequence and 3′-end deletion studies indicate that the K+-uptake protein Kup from Escherichia coli is composed of a hydrophobic core linked to a large and partially essential hydrophobic C terminus. J Bacteriol 175:6925–6931
Senn ME, Rubio F, Banuelos MA, Rodriguez-Navarro A (2001) Comparative functional features of plant potassium HvHAK1 and HvHAK2 transporters. J Biol Chem 276:44563–44569
Su H, Golldack D, Zhao C, Bohnert HJ (2002) The expression of HAK-type K+ transporters is regulated in response to salinity stress in common ice plant. Plant Physiol 129:1482–1493
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Communicated by W.-H. Wu.
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Takahashi, R., Nishio, T., Ichizen, N. et al. High-affinity K+ transporter PhaHAK5 is expressed only in salt-sensitive reed plants and shows Na+ permeability under NaCl stress. Plant Cell Rep 26, 1673–1679 (2007). https://doi.org/10.1007/s00299-007-0364-1
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DOI: https://doi.org/10.1007/s00299-007-0364-1