Regulation of Ethylene Production by Ripening Nectarine Fruit as Influenced by Ethylene and Low Temperature

Abstract

Abstract The rise in C2H4 production during nectarine [Prunus persica (L.) Batsch] fruit ripening at 20°C was accompanied by an increase in the level of 1-aminocyclo-propane-1-carboxylic acid (ACC) and ACC synthase activity. Activity of the C2H4-forming enzyme (EFE) also increased during ripening, but the level was at least 2-times greater than the C2H4 production rate at all stages. C2H4 treatment significantly increased C2H4 production rate, ACC accumulation, and ACC synthase activity. Ability to convert ACC to C2H4, however, was reduced following C2H4 treatment. An increase in total C2H4 production at 20° following storage of nectarines at 0° for up to 4 days was attributable to enhanced ACC synthase activity. Exposure to C2H4 at 0° for more than 4 days reduced C2H4 production and EFE activity during ripening. Increased accumulation of ACC and lowered EFE activity following prolonged C2H4 treatments at 0° suggests that C2H4 production during ripening of fruit held under these conditions is limited by slowed conversion of ACC to C2H4.