Relationship of Polyamine Content to ACC Content and Ethylene Evolution in Japanese Apricot Fruit

Abstract

The polyamine and ACC contents in mesocarp of Japanese apricot (Prunus mume Sieb. et Zucc.) were determined during fruit development. Polyamine and ACC levels peaked in the early fruit development stage, followed by 'June drop'. Then, polyamine and ACC levels decreased rapidly and changed little until fruit was harvested. The content of spermidine (Spd) in the mesocarp sharply declined during the post-harvest period, but the levels of spermine (Spn) and putrescine (Put), did not change. ACC and ethylene levels peaked 34 days after harvest. Exogenous polyamines, applied to fruit 20 days before normal harvest, delayed fruit drop and ethylene evolution after harvest as compared to the control.