Cytokinins in Germinating Seeds of Phaseolus vulgaris L. II. Transport and Metabolism of 8[14C]t-Zeatin Applied to the Radicle

Abstract

The application of 8[¹⁴C]t-zeatin to the radicle tips of germinating Phaseolus vulgaris seeds revealed that cytokinins are transported rapidly from the embryonic axis to the cotyledons, and are utilized and metabolized extensively in these organs. The information obtained on the transportation between the different parts of the embryo is consistent with the view that the mobilization of food reserves from the cotyledons is controlled by cytokinins which originate in the embryonic axis. Tentative identification of the radioactive metabolites formed indicate that the applied zeatin was altered by side-chain cleavage and by substitution to the adenine ring.