Figure 6.

Radioactive tracer flux analysis of Rb⁺ uptake in atmrp5-2 and wild-type roots. Seedlings were grown in normal Murashige and Skoog medium on vertical plates for 4 d, transferred to either normal or modified Murashige and Skoog medium containing 100 μm KCl and allowed to grow for 3 d. ⁸⁶Rb⁺ uptake assays were performed in 1/20-strength major Murashige and Skoog salts with normal amounts of micronutrients supplemented with 100 μm KCl and 0.5 μCi mL^{-1 86}Rb⁺. Black bars, seedlings grown in normal Murashige and Skoog medium for 4 d, transferred to the same medium, and grown for 3 d. White bars, Seedlings grown in normal Murashige and Skoog medium for 4 d and transferred to modified Murashige and Skoog medium with 100 μm KCl and grown for 3 d.