Biological Control of the Resistance to Oxygen Flux in Nodules

Abstract

Experiments have been conducted to investigate the response of symbiotic nitrogen fixation in white clover to different concentrations of oxygen around the root. Over a wide range of oxygen concentrations (21–80 per cent) there was little variation in respiration and no evidence of damage to nitrogenase. It is suggested that, in the absence of respiratory protection, oxygen damage to nitrogenase is prevented by changes in the resistance to gaseous diffusion.