Studies in the Respiratory and Carbohydrate Metabolism of Plant Tissues1

Abstract

Low concentrations of iodoacetate produced large increases in CO₂ output of strawberry leaves which were not completely accounted for by the observed losses of sugars and starch. No significant change was observed in RQ in iodoacetate but the values, either in water or in iodoacetate, were generally below unity. Thus, in addition to other carbohydrates not estimated in our work, there may also be respiration of protein or organic acids. The increased rate of CO₂, output in iodoacetate was associated with rises in pyruvate and oxaloacetate but citrate and α-ketoglutarate remained unchanged. The former changes suggested a faster traffic into the tricarboxylic acid cycle; the content of oxaloacetate appeared to be a close index of the rate of this traffic. A tentative interpretation is given of the anomalous behaviour of citrate and α-ketoglutarate in iodoacetate.