text: C3 carbon fixation is prone to photorespiration (PR) during dehydration, accumulating toxic glycolate products. In the 2000s scientists used computer simulation combined with an optimization algorithm to figure out what parts of the metabolic pathway may be tuned to improve photosynthesis. According to simulation, improving glycolate metabolism would help significantly to reduce photorespiration.
  Instead of optimizing specific enzymes on the PR pathway for glycolate degradation, South et al. decided to bypass PR altogether. In 2019, they transferred Chlamydomonas reinhardtii glycolate dehydrogenase and Cucurbita maxima malate synthase into the chloroplast of tobacco (a  model organism). These enzymes, plus the chloroplasts own, create a catabolic cycle: acetyl-CoA combines with glyoxylate to form malate, which is then split into pyruvate and CO; the former in turn splits into acetyl-CoA and CO. By forgoing all transport among organelles, all the CO released will go into increasing the CO concentration in the chloroplast, helping with refixation. The end result is 24% more biomass. An alternative using E. coli' glycerate pathway produced a smaller improvement of 13%. They are now working on moving this optimization into other  crops like wheat.