Effect of OsHAK18 expression level on Rb⁺ transport in rice plants. A) Schematic diagram of split-root experiment. B) Rb⁺ content percentage (i.e. the percentage of the total Rb⁺ acquired by the plant) in different plant parts in OsHAK5-OX lines and their corresponding WT at 3 and 6 h of the pulse chase. C)OsHAK18-KO lines and their corresponding WTs. D)OsHAK18-OX lines and their corresponding WT. Root-Rb⁺, root exposed to Rb⁺; Root-K⁺, root not exposed to Rb⁺. Each treatment contains 7 (B) and C)) or 6 (D)) biological replicates. The box plots and t tests are as in Fig. 2. Significant differences from the corresponding WT are indicated by asterisks (*P<0.05; **P<0.01; ***P<0.001).