Inhibition of Ethylene Synthesis and Action in Ripening Tomato Fruit by Ethanol Vapors

Abstract

Abstract Exposure of whole fruit, slices, or pericarp disks of tomato (Lycopersicon esculentum Mill.) to 0.5 to 3.0 ml absolute ethanol vaporized in a 4-Iiter container for 3 hr significantly reduced the climacteric rise in CO2 and C2H4 production, lycopene synthesis, and chlorophyll loss. Inhibition of ripening occurred whether fruit were at the mature-green or breaker-turning stage. Whole fruit recovered and ripened normally after a delay that was related to the tissue ethanol concentration. Treated slices did not ripen normally, and exposure to 16 μl C2H4/liter did not promote ripening. The level of ACC was 14-fold higher in treated slices, while C2H4 production was reduced 70%. Treatments with AVG and ACC indicated that ethanol inhibited ACC conversion to C2H4. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC); [S-(E)]-2-amino-4-(2-aminoethoxy)-3-butyric acid (AVG).