Adenine incorporation into cytokinins in aseptically cultured tomato roots

Excised tomato roots cultured in a liquid medium were used to investigate the fate of applied (8-(14)C) adenine over a 12 day period. Root material and the staled culture medium were analysed separately for cytokinin-like activity. In both cases the major radioactive compound recovered co-chromatographed with authentic adenine. Root material also yielded low levels of radioactive compounds which after Sephadex LH-20 fractionation and HPLC analysis cochromatographed with zeatin, ribosylzeatin, adenosine, and glucosylzeatin. Both the root material and the culture medium contained a larger, unidentified, polar peak which did not respond to alkaline phosphatase or β-glucosidase treatments.