Main Article Content
Abstract: Salt stress leads to serious inhibiting of the growth and development of plants. The selection and generation of plants resistant to salinity is effective and sustainable way to overcome the saline soil. It has been proven that the HKT transporter is involved in salinity tolerance in plants. OsHKT2;4 gene is a member of class II of HKT gene family in rice encoding protein which mediates Na+-K+ cotransport and at high Na+ concentration preferred Na+ -selective transport. In this study, the natural variations in OsHKT2;4 gene sequence was investigated in some Vietnamese rice cultivars. The full length of gene sequence was amplified by PCR, followed by direct sequencing of PCR product. Analysis of obtained sequences among cultivars revealed the 11 single nucleotide polymorphisms, consisting of 8 sites in exons and 3 sites in intron. Further analysis showed that these 8 substitutions in exons were non-synonymous which caused changes in amino acids at signal peptide (S11F and N17T), at the loop (T66V, T84I, S133L, S342N) and the transmembranes (V53M, L253F).Keywords: Genetic polymorphism, HKT, rice, OsHKT2;4.
 A.Rodríguez-Navarro, Potassium transport in fungi and plants. Biochim Biophys Acta 1469(2000) 1.
 A. Rodríguez-Navarro, F. Rubio. High-affinity potassium and sodium transport systems in plants. J Exp Bot 57(2006) 1149.
 C. Corratgé-Faillie, M. Jabnoune, S. Zimmermann, A-A. Véry, C. Fizames, H. Sentenac. Potassium and sodium transport in non-animal cells: The Trk/Ktr/HKT transporter family. Cell Mol Life Sci 67(2010) 2511.
 D.P. Schachtman, J.I. Schroeder., Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plants. Nature 370(1994) 655.
 J.D. Platten, O. Cotsaftis, P. Berthomieu, H. Bohnert, R.J. Davenport, D.J. Fairbairn, T. Horie, R.A. Leigh, H.X. Lin, S. Luan, et al, Nomenclature for HKT transporters, key determinants of plant salinity tolerance, Trends Plant Sci 11(2006) 372.
 A.Sassi, D. Mieulet, I. Khan, B. Moreau, I. Gaillard, H. Sentenac and A-A. Véry, The rice monovalent cation transporter OsHKT2;4: Revisited ionic selectivity1. Plant Physiology, 160(2012) 498.
 T. Horie, K. Yoshida, H. Nakayama, K. Yamada, S. Oiki, A. Shinmyo, Two types of HKT transporters with different properties of Na+ and K+ transport in Oryza sativa. Plant J 27(2001)129.
 T. Horie, D. Brodsky, A. Costa, T. Kaneko, F. Schiavo, M. Katsuhara, J.K. Schroeder, 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 156 (2011) 1493.
 S. Huang, W. Spielmeyer, E.S. Lagudah, R. Munns, Comparative mapping of HKT genes in wheat, barley, and rice, key determinants of Na+ transport, and salt tolerance. J Exp Bot 59 (2008) 927.
 P. Almeida, D. Katschnig and A.H. Boer, HKT trasporter- state of the art. Int. J. Mol. Sci. (2013) 20360.
 Z.H. Ren, J.P. Gao, L.G. Li, X.L. Cai, W. Huang, D.Y. Chao, M.Z. Zhu, Z.Y. Wang, S., H.X. Lin. A rice quantitative trait locus for salt tolerance encodes a sodium transporter. Nat. Genet. 37 (2005) 1141.
 O. Cotsaftis, D. Plett, N. Shirley, M. Tester, M. Hrmova A two-staged model of Na+ exclusion in rice explained by 3D modeling of HKT transporters and alternative splicing. PLoS ONE (2012) 7:e39865.
J.J. Doyle and J.L. Doyle, Isolation of plant DNA from fresh tissue. Focus 12 (1990) 13.