Participation of the Mehler Reaction and Catalase in the Oxygen Exchange of Chloroplast Preparations

Abstract

We have reinvestigated several aspects of the Mehler reaction in isolated chloroplasts. We have confirmed that the rate of oxygen uptake is accelerated by a number of biological and artificial electron carriers. The Mehler reaction also responds to uncoupling agents and exhibits photosynthetic control with ADP. In the presence of catalase, steady-state oxygen exchange may be established and lead to such apparent anomalies as oxygen uptake in the light followed by oxygen evolution in the dark. The steady state is a function of catalase concentration, light intensity, and the presence and concentration of electron carriers, etc., which affect the rate of the Mehler reaction.