CHANGES OF 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID AND OF ITS CONJUGATE DURING TOMATO FRUIT RIPENING

Distribution and changes in the levels of ACC and of its conjugate, malonyl ACC (MACC), have been studied in the whole fruit, the pericarp plus peel and the locular content of tomatoes (Lycopersicon esculentum Mill.) at 6 ripening stages previously characterized by the lycopene content, the firmness and the CO₂ production rate of the fruits. According to the free ACC patterns of changes, three phases related to the ethylene production could be distinguished in all the tissues, and the development of locular content was more advanced than that of pericarp during tomato fruit ripening. In contrast to free ACC levels, MACC levels are similar in locular and pericarp tissues and increase immediately after the ethylene peak.