EXPRESSION OF ACC OXIDASE ANTISENSE GENE INHIBITS RIPENING OF CANTALOUPE MELON FRUITS

The plant hormone ethylene plays a major role in the ripening of clima cteric fruit. We have generated transgenic cantaloupe Charentais melon s expressing an antisense ACC oxidase gene; ACC oxidase catalyzes the last step of ethylene biosynthesis. Ethylene production of transgenic fruit was <1% of control untransformed fruit, and the ripening process was blocked both on and off the vine. The antisense phenotype could b e reversed by exogenous ethylene treatment. Analysis of antisense ACC oxidase melons indicated that the ripening process includes ethylene-d ependent and ethylene-independent pathways. Because the transgenic lin e we generated displays extended storage life and improved quality, it has a promising potential for commercial development.