Brisson et al.75 reported that by increasing the amount of catalase, photorespiration can be reduced in transgenic tobacco plants. It has been estimated that 25% of the glycolate metabolized during photorespiration is released as CO2 at 25°C. There is evidence that stoichiometry of the CO2 produced per mol of glycolate oxidized, increases under conditions favouring rapid photorespiration, such as increase in O2 and temperature. During photorespiratory carbon flow, huge amounts of H2O2 are generated in the peroxisomes as a result of oxidation of glycolate. The excess of H2O2 rapidly decarboxylates keto acids such as hydroxypyruvate and glyoxylate to generate additional CO2. This additional loss of assimilated CO2 might be avoided with higher catalase activity, thereby reestablishing the stoichiometry close to 25% and increasing net photosynthesis