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

Abstract

Detached spruce twigs, wheat and soybean leaves were infiltrated with various metabolic inhibitors, placed in a closed system in CO2-free air and the amounts of CO2 evolved in either light or darkness were determined with an infra-red CO2 analyzer. In light, metabolic inhibitors always greatly suppressed evolution of CO2, 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 CO2 evolution. These observations have been taken as further support for a conclusion made earlier, that evolution of CO2 in light and darkness is not the same process.