Behaviors of 1-Aminocyclopropane-1-carboxylic Acid(ACC) and ACC Synthase Responsible for Ethylene Production in Normal and Mutant(nor and rin) Tomato Fruits at Various Ripening Stages.

Abstract

The behavior of 1-aminocyclopropane-1-carboxylic acid (ACC) and ACC synthase respon- sible for ethylene production was studied using three types of tomato fruits; 'Beiju' as a ripen- ing type, nor mutant as an intermediate ripening type and rin mutant as a non-ripening type. In 'Beiju' tomatoes, the rate of ethylene production, ACC synthase activity. and the amounts of ACC and 1- (malonylamino) cyclopropane-1-carboxylic acid (MACC) increased with ripen- ing. In nor tomatoes, a slight increase in ethylene production and ACC synthase activity was observed about 50 days after anthesis. ACC and MACC accumulated markedly during the late stage of fruit development. In rin tomatoes, on the other hand, the activity of ACC syn- thase and the amounts of ACC and MACC hardly changed at any stage and the rate of eth- ylene production also remained nearly constant. Wounding the pericarp tissue in Yin tomatoes induced ACC synthase activity, whereas the activity was scarcely observed in intact fruits. Wounding of 'Beiju' and nor tomatoes during fruit development accelerated ACC synthase activity markedly and the seasonal patterns of the activity in the wounded fruits were simi- lar to that in intact fruits.