Assessment of Natural Variation in OsHKT1;2 Gene in Rice (Oryza sativa)
Main Article Content
Abstract
Abstract: HKT gene family encodes Na+ and/or K+ transporter located on cellular membrane in plants. HKT transporter family has been proven to play a crucial role in maintaining low Na+/K+ ratio to help plant survive during saline condition. OsHKT1;2 gene is a member of rice HKT gene family. However, the functional roles of the OsHKT1;2 is reminded unknown. In this study, we investigated the natural variations in coding sequence of OsHK1;2. Firstly, the coding sequence of OsHKT1;2 was amplified by PCR using specific primers in 13 different rice cultivars, then the PCR products were directly sequenced. The results revealed two nucleotide variations at position 343 and 1413 in eight rice cultivars. However, the predicted amino acid sequence showed three early stop codons presenting within the exon 1 in all 13 investigated rice cultivars, suggesting that OsHKT1;2 might be a pseudogene that might not produce full-length protein.
Keywords: OsHKT1;2 rice, salt stress, natural variation.References
[2] D.W. Rains, E. Epstein E, Transport of sodium in plant tissue. Science 148 (1965), 1611
[3] A.M. Rus, R.A. Bressan, P.M. Hasegawa, Unraveling salt tolerance in crops, Nature Genetics 37 (2005) 1029–30
[4] P. Berthomieu, G. Conejero, A. Nublat, et al, Functional analysis of AtHKT1 in Arabidopsis shows that Na+ recirculation by the phloem is crucial for salt tolerance. EMBO Journal 22 (2003), 2004–14
[5] B. Garciadebla´s, M.E. Senn, M.A. Banuelos, A. Rodriguez-Navarro, Sodium transport and HKT transporters: the rice model, The Plant Journal 34 (2003), 788–801
[6] M. Jabnoune, S. Espeout, D. Mieulet, C. Fizames, J.L. Verdeil, G. Cone´je´ro, A. Rodrı´guez-Navarro, H. Sentenac, E. Guiderdoni, C. Abdelly, et al, Diversity in expression patterns and functional properties in the rice HKT transporter family. Plant Physiol 150 (2009), 1955–71
[7] 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. The Plant Journal 27 (2001) 129–38
[8] P. Ma¨ser, Y. Hosoo, S. Goshima, Glycine residues in potassium channel-like selectivity filters determine potassium selectivity in four-loop-per-subunit HKT transporters from plants. PNAS 99 (2002) 6428–33
[9] R.A. James et al, Impact of ancestral wheat sodium exclusion genes Nax1 and Nax2 on grain yield of durum wheat on saline soils. Funct. Plant Biol 39 (2012) 609–18
[10] Z.H. Ren, J.P. Gao, L.G. Li, X.L. Cai, W. Huang, D.Y. Chao, , M.Z. Zhu,Z.Y. Wang, S. Luan and H.X. Lin, A rice quantitative trait locus for salt tolerance encodes a sodium transporter, Nat. Genet 37 (2005), 1141–46
I. Baxter, J.N. Brazelton, D. Yu D, A coastal cline in sodium accumulation in Arabidopsis thaliana is driven by natural variation of the sodium transporter AtHKT1;1. PLoS Genet. 6 (2010) e1001193