PtHAK5, a candidate for mediating high-affinity K⁺ uptake in the halophytic grass, Puccinellia tenuiflora

Abstract

Puccinellia tenuiflora is a typical salt-exclu-ding halophytic grass with strong salt-tolerance, which enhances tolerance by restricting Na⁺ influx as well as having a strong selectivity for K⁺ over Na⁺. The HAK5 K⁺ transporters generally modulate effective K⁺ acquisition in plants, especially under low K⁺ condition. In this study, PtHAK5 from P. tenuiflora was isolated by RT-PCR and characterized using yeast complementation. The results showed PtHAK5 consisted of 784 amino acids and shared over 80% homology with the identified high-affinity K⁺ transporter HAK5 from other higher plants. The expression of PtHAK5 rescued the K⁺-uptake-defective phenotype of yeast strain CY162. In conclusion, PtHAK5 is a candidate for mediating high-affinity K⁺ uptake under low K⁺ conditions.

Keywords

K⁺ uptake / PtHAK5 / Puccinellia tenuiflora / yeast complementation

References

[1] Anschütz U, Becker D, Shabala S. Going beyond nutrition: regulation of potassium homoeostasis as a common denominator of plant adaptive responses to environment. Journal of Plant Physiology, 2014, 171(9): 670–687

[2] 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 Journal, 1995, 14(13): 3021–3027

[3] Rubio F, Santa-María G E, Rodríguez-Navarro A. Cloning of Arabidopsis and barley cDNAs encoding HAK potassium transporters in root and shoot cells. Physiologia Plantarum, 2000, 109(1): 34–43

[4] Evans H J, Sorger G J. Role of mineral elements with emphasis on the univalent cations. Annual Review of Plant Physiology, 1966, 17(1): 47–76

[5] Ashley M K, Grant M, Grabov A. Plant responses to potassium deficiencies: a role for potassium transport proteins. Journal of Experimental Botany, 2006, 57(2): 425–436

[6] Gierth M, Mäser P. Potassium transporters in plants—involvement in K⁺ acquisition, redistribution and homeostasis. FEBS Letters, 2007, 581(12): 2348–2356

[7] Gupta M, Qiu X, Wang L, Xie W, Zhang C, Xiong L, Lian X, Zhang Q. KT/HAK/KUP potassium transporters gene family and their whole-life cycle expression profile in rice (Oryza sativa). Molecular Genetics and Genomics, 2008, 280(5): 437–452

[8] Yang T, Zhang S, Hu Y, Wu F, Hu Q, Chen G, Cai J, Wu T, Moran N, Yu L, Xu G. The role of a potassium transporter OsHAK5 in potassium acquisition and transport from roots to shoots in rice at low potassium supply levels. Plant Physiology, 2014, 166(2): 945–959

[9] Kim E J, Kwak J M, Uozumi N, Schroeder J I. AtKUP1: an Arabidopsis gene encoding high-affinity potassium transport activity. Plant Cell, 1998, 10(1): 51–62

[10] Senn M E, Rubio F, Bañuelos M A, Rodríguez-Navarro A. Comparative functional features of plant potassium HvHAK1 and HvHAK2 transporters. Journal of Biological Chemistry, 2001, 276(48): 44563–44569

[11] Garciadeblas B, Benito B, Rodríguez-Navarro A. Molecular cloning and functional expression in bacteria of the potassium transporters CnHAK1 and CnHAK2 of the seagrass Cymodocea nodosa. Plant Molecular Biology, 2002, 50(4-5): 623–633

[12] Horie T, Brodsky D E, Costa A, Kaneko T, Lo Schiavo F, Katsuhara M, Schroeder J I K. K⁺ transport by the OsHKT2;4 transporter from rice with atypical Na⁺ transport properties and competition in permeation of K⁺ over Mg²⁺ and Ca²⁺ ions. Plant Physiology, 2011, 156(3): 1493–1507

[13] Grabov A. Plant KT/KUP/HAK potassium transporters: single family-multiple functions. Annals of Botany, 2007, 99(6): 1035–1041

[14] Nieves-Cordones M, Alemán F, Martínez V, Rubio F. K⁺ uptake in plant roots. The systems involved, their regulation and parallels in other organisms. Journal of Plant Physiology, 2014, 171(9): 688–695

[15] Wang S, Zhao G, Gao Y, Tang Z, Zhang C. Puccinellia tenuiflora exhibits stronger selectivity for K⁺ over Na⁺ than wheat. Journal of Plant Nutrition, 2004, 27(10): 1841–1857

[16] Wang C M, Zhang J L, Liu X S, Li Z, Wu G Q, Cai J Y, Flowers T J, Wang S M. Puccinellia tenuiflora maintains a low Na⁺ level under salinity by limiting unidirectional Na⁺ influx resulting in a high selectivity for K⁺ over Na⁺. Plant, Cell & Environment, 2009, 32(5): 486–496

[17] Zhu J K. Regulation of ion homeostasis under salt stress. Current Opinion in Plant Biology, 2003, 6(5): 441–445

[18] 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. Proceedings of the National Academy of Sciences of the United States of America, 1992, 89(9): 3736–3740

[19] Mäser P, Thomine S, Schroeder J I, Ward J M, Hirschi K, Sze H, Talke I N, Amtmann A, Maathuis F J M, Sanders D, Harper J F, Tchieu J, Gribskov M, Persans M W, Salt D E, Kim S A, Guerinot M L. Phylogenetic relationships within cation transporter families of Arabidopsis. Plant Physiology, 2001, 126(4): 1646–1667

[20] Quintero F J, Garciadeblás B, Rodríguez-Navarro A. The SAL1 gene of Arabidopsis, encoding an enzyme with 3′(2′),5′-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities, increases salt tolerance in yeast. Plant Cell, 1996, 8(3): 529–537

[21] BLAST—a gene sequence alignment tool of NCBI platform. NCBI-BLAST service, available on January 2, 2016

[22] GeneBank, the NIH genetic sequence database. NCBI-GeneBank service, available on January 6, 2016

[23] TMHMM—a software used to predict transmembrane helices of integral membrane proteins. CBS-TMHMM service, available on January 14, 2016

[24] Tamura K, Dudley J, Nei M, Kumar S. MEGA4: molecular evolutionary genetics analysis (MEGA) software version 4.0. Molecular Biology and Evolution, 2007, 24(8): 1596–1599

[25] ORF finder searches for open reading frames (ORFs) in the DNA sequence. NCBI-ORFfinder service, available on January 10, 2016

[26] Mumberg D, Müller R, Funk M. Yeast vectors for the controlled expression of heterologous proteins in different genetic backgrounds. Gene, 1995, 156(1): 119–122

[27] Chen D C, Yang B C, Kuo T T. One-step transformation of yeast in stationary phase. Current Genetics, 1992, 21(1): 83–84

[28] Rodríguez-Navarro A, Ramos J. Dual system for potassium transport in Saccharomyces cerevisiae. Journal of Bacteriology, 1984, 159(3): 940–945

[29] Sentenac H, Bonneaud N, Minet M, Lacroute F, Salmon J M, Gaymard F, Grignon C. Cloning and expression in yeast of a plant potassium ion transport system. Science, 1992, 256(5057): 663–665

[30] Uozumi N, Kim E J, Rubio F, Yamaguchi T, Muto S, Tsuboi A, Bakker E P, Nakamura T, Schroeder J I. The Arabidopsis HKT1 gene homolog mediates inward Na⁺ currents in xenopus laevis oocytes and Na⁺ uptake in Saccharomyces cerevisiae. Plant Physiology, 2000, 122(4): 1249–1259

[31] Su H, Golldack D, Zhao C, Bohnert H J. The expression of HAK-type K⁺ transporters is regulated in response to salinity stress in common ice plant. Plant Physiology, 2002, 129(4): 1482–1493

[32] Rodríguez-Navarro A. Potassium transport in fungi and plants. Biochimica et Biophysica Acta, 2000, 1469(1): 1–30

[33] Santa-María G E, Rubio F, Dubcovsky J, Rodríguez-Navarro A. The HAK1 gene of barley is a member of a large gene family and encodes a high-affinity potassium transporter. Plant Cell, 1997, 9(12): 2281–2289

[34] Nieves-Cordones M, Alemán F, Martínez V, Rubio F. The Arabidopsis thaliana HAK5 K⁺ transporter is required for plant growth and K⁺ acquisition from low K⁺ solutions under saline conditions. Molecular Plant, 2010, 3(2): 326–333

Acknowledgements

This work was supported by the National Natural Science Foundation of China (31730093, 31470503).

Compliance with ethics guidelines

Haili Yang, Weidan Zhang, Weiwei Chai, Wenying Wang, Li Gao, Jing Zhang, Yongping Wang, and Suo-Min Wang declare they have no conflicts of interest or financial conflicts to disclose.

This article does not contain any studies with human or animal subjects performed by any of the authors.

RIGHTS & PERMISSIONS

The Author(s) 2018. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)