A biotechnological approach to increase carbon assimilation in C3-plants

• Applicant: Professorin Dr. Veronica Maurino
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2006 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 25780487

Photorespiration starts with the competitive inhibition of CO2 fixation by O2 at the active site of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and results in a loss of at least 25% of the CO2 fixed in ambient air in C3-plants. Thus, photorespiration was considered a potentially wastefull proces that was limiting plant productivity. The prime function of the C2-pathway is to salvage glycolate 2-P by conversion to glycerate 3-P, which re-enters the C3-reductive cycle. We attempt to introduce two alternative and complete glycolate catabolic cycles into chloroplasts of the model plant Arabidopsis thaliana in order to release and re-fix the CO2 directly within the chloroplast, thereby reducing the oxygenase activity of Rubisco by increasing the CO2/O2 ratio. Thus, an autoregulatory cycle would be created which results in an attenuation of the photorespiratory pathway and an expected improvement in the efficiency of CO2 assimilation and consequently, faster biomass production. Analyses of transformants harboring fully operational glycolate cycles will also generate data to complement our understanding of function and regulation of the photorespiratory pathway and its interaction with other processes.

• DFG Programme: Research Grants