Photosynthesis 2.0: Realizing New-to-Nature CO2-Fixation to Overcome the Limits of Natural Metabolism

Abstract

Synthetic biology provides opportunities to realize new-to-nature CO₂-fixation metabolisms to overcome the limitations of natural photosynthesis. Two different strategies are currently being pursued: One is to realize engineered plants that feature carbon-neutral or carbon-negative (i.e., CO₂-fixing) photorespiration metabolism, such as the tatronyl-CoA (TaCo) pathway, to boost CO₂-uptake rates of photosynthesis between 20% and 60%. Another (arguably more radical) is to create engineered plants in which natural photosynthesis is fully replaced by an alternative CO₂-fixation metabolism, such as the CETCH cycle, which carries the potential to improve CO₂ uptake rates between 20% and 200%. These efforts could revolutionize plant engineering by expanding the capabilities of plant metabolism beyond the constraints of natural evolution to create highly improved crops addressing the challenges of climate change in the future.