Effects of Humidity on Ethylene Biosynthesis of Cucumber, Eggplant and Green Pepper Fruits

Abstract

The effect of water deficit on ethylene biosynthesis of cucumber, eggplant and green pepper fruits was studied at 25°C and different humidities (20, 53, 80, 97%RH). Although none or little ethylene production was observed at high humidity, rapid water deficit at low humidity caused ethylene production following a decrease in three kinds of fruits. Elevated ethylene production of the fruits was also induced by rapid fluctuating humidity, and continued of a high level after transferring to high humidity. 1-aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase activity and ACC oxidase activity in peel and pulp of the fruits increased rapidly accompanyed by rapid water deficit in the fruit at low humidity. These results seem to indicate that rapid water deficit at low humidity is unfavorable in the view of keeping the quality of fruits and vegetables, because of accelerating their ethylene biosynthesis.