Effects of Sucrose on the Rate of Respiration of the Roots of Pisum sativum

Summary The aim of this work was to discover if the respiration of the roots of Pisum sativum L. could be increased above that of the normal growing root by the addition of excess sucrose. Incubation of excised roots of pea seedlings in 25, 50 and 100 mM sucrose increased oxygen uptake by roughly 10, 20 and 25%, respectively. Sucrose, supplied to otherwise intact seedlings via the stele exposed 39\2-47 mm from the root apex, did not increase CO 2 production by the apical 25 mm of the root. Growth of pea seedlings with their roots in 50 mM sucrose for 70 h increased neither the growth nor the respiration rate. These results are related to the concept of wasteful oxidation of sucrose.