Effect of OsHAK5 overexpression on rice salt tolerance as indicated by biomass accumulation, K and Na accumulation, and the ratios of their concentrations. Ten-day-old seedlings were grown in IRRI solution containing 1 mm  K for 3 weeks, then transferred to a solution containing additionally 100 mm NaCl and allowed to grow for 8 d. WT(NB), The wild type of cv Nipponbare; OX1 to OX3, three independent lines of OsHAK5-overexpressing plants of cv Nipponbare. Error bars indicate se (n = 5 plants). Significant differences from the wild type in each group are indicated with different letters (P < 0.05, one-way ANOVA).