Na+ in root (a) and leaf tissues (b) and Na+/K+ ratio in root (c) and leaf tissues (d) of Pokkali and IR29, when exposed to control (0 mM NaCl) and salt stress (200 mM NaCl) for 0, 15, 30, 45, 60, 180, 360 min and 168 h. Error bars represent standard error (± SE)