The effect of metyrapone on cytokinin ([8-14C]benzylaminopurine) metabolism in mature green tomato pericarp.

Cytokinin, [8-14C]Benzylaminopurine, metabolism in tomato pericarp was followed during a 3 h period utilizing thin layer chromatography and visualization by fluorography. Fluorography indicated the formation of at least 7 metabolites during 3 h. Cytokinin metabolism was reduced by approximately 40% in 3 h by the presence of 250 microM metyrapone, an inhibitor of cytochrome P-450 related enzyme systems. In the presence of metyrapone, the number of radioactive metabolites on the thin layer plate was reduced from 7 to 4 and 2 of these were unique to the metyrapone-treated sample. These data suggest the initial step in benzylaminopurine metabolism in tomato pericarp may be mediated by a cytochrome P-450 related enzyme system which is altered in the presence of metyrapone.