Relation Between Soil Aeration and Ethyl Alcohol Accumulation in Xylem Exudate of Tomatoes

Abstract

Abstract Experiments were designed to measure the influence of soil oxygen stress and other environmental variables on the accumulation of ethanol in tomato plants. Oxygen stress was imposed by varying the soil moisture tension over a narrow range of low values. Ethanol was observed in the exudate samples when the rate of oxygen diffusion through the soil solution fell below 38 × 10 ‐8 g.cm. ‐2 min. ‐1 . A small reduction in oxygen supply below this value was associated with a large increase in ethanol. In cases of severe oxygen stress the physiological concentration of ethanol was sufficient to be toxic. Plants bearing flowers accumulated more ethanol than younger ones and those subjected to oxygen stress in bright light accumulated more ethanol than those in the dark.