Studies in the Respiratory and Carbohydrate Metabolism of Plant Tissues3

Abstract

A pressure of oxygen of 5 atmospheres has been shown to inhibit markedly the carbon-dioxide output of green shelled peas. Accompanying this decrease, an accumulation of pyruvic and ‘citric’ acid has been noted, whilst a depletion in the concentration of α-ketoglutaric acid and, in some experiments, of malic acid occurred. The results have been interpreted as indicating that high pressures of oxygen interfere with the metabolism of citric acid causing a ‘jamming’ of the tricarboxylic acid cycle; thus, under the conditions prevailing during the oxygen treatment, the tricarboxylic acid cycle is considered to be a major respiratory pathway in peas.