Effects of Metabolic Inhibitors on the Rates of CO2 Evolution in Light and in Darkness by Detached Spruce Twigs, Wheat, and Soybean Leaves

Detached spruce twigs, wheat and soybean leaves were infiltrated with various metabolic inhibitors, placed in a closed system in CO(2)-free air and the amounts of CO(2) evolved in either light or darkness were determined with an infra-red CO(2) analyzer. In light, metabolic inhibitors always greatly suppressed evolution of CO(2), the magnitude of suppression varying between 50 to 80% of that without an inhibitor. This depressing effect became less pronounced with increasing oxygen. In darkness, metabolic inhibitors sometimes suppressed and sometimes stimulated CO(2) evolution. These observations have been taken as further support for a conclusion made earlier, that evolution of CO(2) in light and darkness is not the same process.