Temperature dependence of respiration rates of leaves, 18O-experiments and super-Arrhenius kinetics

Abstract Temperature dependence of rates of respiration in the dark of leaves from a worldwide diffuse, evergreen plant, Camellia Japonica , was measured by mass spectrometry. Oxygen-18 isotopic labeling shows that consumption of O 2 goes exclusively into water, demonstrating that this process and that of CO 2 production occur separately in different areas of mitochondria, concerted by exchange of electrons and protons. The observed larger-than-normal acceleration of the global process as temperature increases is described consistently by a microscopic model inspired by recent case studies in materials science, implying a crucial role of transport for the coupling between oxygen reduction and carbon oxidation.