The absorption and subsequent transport of foliar applied Rb ss labeled Rb C1 (10 raM) was studied on bean plants (Phaseolus vulgaris, L. cv. Black Seeded Blue Lake) exposed to physiologically tolerable levels o~ certain plant growth substances in the solution culture root media. Gibberellin A s (10 -s M) increased Rb uptake but did not affect total translocation from the treated leaf. Translocation was directed to the upper vegetative parts and markedly reduced to the roots. Foliar influx of t~b and transport to the roots were greatly enhanced by 1-naphthaleneacetic acid (I0 -s M) but mobilization of Rb into the leaves and upper stem was reduced. 2-Chloroethy]trimethylammonium chloride (10 -s M) and N,N-dimethylaminosuccinamic acid (3 โข 10 -5 M) decreased the mobility of Rb to the upper stem, increased it to the roots, and had no effect on initial uptake. Rb absorption was depressed by 2,4-dichlorobenzyltributylphosphonimn chloride (10 -5 M) with no effect on subsequent transloeation. Both uptake and mobility were strikingly inhibited by N6-benzyladenine (10 -6 M).
These results suggest that absorption and the subsequent transport of foliar absorbed Rb are independent processes and thst the distribution or mobilization of Rb in the various plant organs was not always a function of the chemically modified growth rate of the corresponding organ.