Influence of Cobalt on Leaf Expansion and Oxidative Phosphorylation

Abstract

Evidence is presented showing that Co++-induced leaf expansion is not susceptible to inhibition by 2,4-dinitrophenol (DNP). The amount of adenosine tri-phosphate (ATP) in leaf tissue decreases sharply in the presence of DNP. Furthermore, experiments with mitochondria isolated from sweet potato tubers show that Co++ increases the yield of oxidative phosphorylation. Results are presented which indicate that the cobaltous ion has an inhibiting effect on adenosine triphosphatase activity.