Fig. 1. PCR products using four pairs of primers. A, PCR product of 499 bp using primer pair 1 (F1); B, PCR product of 828 bp using primer pair 2 (F2); C, PCR product of 603 bp using primer pair 3 (F3); D, PCR product of 668 bp using primer pair 4 (F4). M, 1 kb ladder marker; Lanes 1 to 9, Nipponbare, Nep Non Tre, Chiem Cu, Re Nuoc, Hom Rau, Nep Oc, Ngoi, Dau An Do and Nep Deo Dang, respectively.

Fig. 2. Polymorphism in OsHKT1 sequence. A, Schematic representation of polymorphism locations in the protein. The position of changes in amino acid are indicated with a star; MPM, transmembrane-pore loop-transmembrane domain. B, Nucleotide sequence of OsHKT1 was compared among the cultivars with the Nipponbare sequence. Non-synonymous substitutions are indicated in dark grey, and the encoded amino acids are listed above. Synonymous substitutions are indicated in light grey. G17V means that glycine is replaced by valine; D403E means that aspartic acid is replaced by glutamic acid.

Fig. 3. 3D ribbon model of OsHKT1 protein visualized by Discovery studio 4.5 visualizer. A, 3D ribbon model of Ni-OsHKT1 protein visualized from the top that shows the pore. Four residues in Ser-Gly-Gly-Gly ion selection motif are labeled and Na+ ion is indicated as a black round circle at the center of the pore. B, Visualization of Ho-OsHKT1 transporter from the side that shows the zoom in D403E variance position (green) (G17V substitution belongs to the signal peptide so they are not modeled in 3D structure of OsHKT1 transporter).