8-[14C]Benzylaminopurine Translocation in Phaseolus vulgaris

Abstract
[8-14C]Benzylaminopurine (BA) translocation was studied in whole plants of P. vulgaris L. under 3 different light regimes (continuous light, 8 h light + 16 h dark, dark). Applications were made to the apex, to a cotyledonary leaf, or to the root system. No BA basipetal translocation occurred; BA is easily absorbed by the root system and is translocated acropetally. The amount of BA absorbed and its acropetal translocation rate depend on the light regime. The hypothesis of a passive cytokinin transport through the xylem, regulated by the transpiration stream, is discussed.