Diurnal Rb+ transport inPhaseolus pulvinus

Transport of Rb⁺ from the roots to the pulvinus and its diurnal movement in the pulvinus were investigated. Rb⁺ was given to the roots as its chloride or nitrate. The results showed that (1) Rb⁺ was transported from the roots to the pulvinus through the hypocotyl, epicotyl and petiole, (2) Rb⁺ was absorbed into the pulvinus in exchange for K⁺, (3) the absorbed Rb⁺ moved diurnally in the same phase as the remaining K⁺. Namely, Rb⁺ moved in the pulvinus diurnally just like K⁺.