Radiorespirometric Studies of Glucose Catabolism in Tomato Fruit

Abstract

The amount of fruit glucose in the immediate infiltrated area when Cl4 labeled glucose is administered into tomato by means of vacuum infiltrated technique has been determined by the isotopic dilution method in conjunction with radiorespirometry. It appears that the labeled glucose was indeed infiltrated into a well defined area in the fruit. Additional results obtained in a series of radiorespirometric experiments on the utilization of C14 specifically labeled acetate, pyruvate and gluconate by tomato fruit revealed the following (a) pyruvate is catabolized by way of oxidative decarboxylation giving rise to acetyl CoA which in turn is oxidized via the TCA cyclic processes, (b) gluconate is catabolized extensively via the 6-phosphogluconate decarboxylation reaction and pentose phosphate cycle reactions giving rise to the reformation of glucose molecules, (c) the reformed hexose phosphate is believed to be catabolized via mainly the Embden-Meyerhof-Parnas pathway.