Metabolism of glucose during ripening of detached tomato fruit.

Abstract

AbstractDetached tomato fruit at four stages of ripeness were injected with D‐[U‐14C]‐glucose. After 72 h the overall metabolism of the labelled glucose and the production of 14CO2 were greatest in red fruit and least in over‐ripe fruit. Labelled carbon was incorporated into the neutral, basic and acidic fractions of fruit at all stages of ripeness. Labelling of free fructose occurred; this was most marked in mature green and green/yellow fruit and declined during subsequent ripening. Incorporation of 14C into sucrose was observed, and this increased with ripening although there was a decrease in total (free and combined) fructose labelling. The results suggest that the sucrose synthesis takes place through the action of sucrose phosphate synthetase rather than sucrose synthetase.