The invention relates to a method for the production of plants with suppressed photo-respiration and improved CO.sub.2 fixation. In particular, the invention relates to a re-use of phosphoglycolate produced in photorespiration. The reaction product will be converted to a component that may be reintegrated into the plant assimilatory metabolism inside the chloroplast. This is accomplished by the transfer of genes derived from glycolate-utilizing pathways from bacteria, algae, plants and/or animals including humans into the plant nuclear and/or plastidial genome. The method of the invention leads to a reduction of photorespiration in C.sub.3 plants and by this will be of great benefit for food production especially but not exclusively under non-favourable growth conditions.