Rate-limiting steps in photorespiratory metabolism and their importance for metabolic regulation

Photosynthesis and photorespiration form an overlapping reaction network in which the photorespiratory C2 cycle is generally regarded as a rather unregulated metabolic process. Similarly, regulatory interactions between the two processes have not been well analysed. Our group plans to identify metabolic constraints to photorespiratory carbon flux and analyse their potential regulatory importance within the pathway and for feed-back regulation of the CB cycle. To this end, we are examining a range of mutants and overexpressor lines for alterations in photorespiratory and related metabolic and transcriptional processes to characterize internal and cross-network carbon fluxes and other interactions. Collected quantitative data serve to develop a computational model of photorespiratory metabolism and used for further improvement and interrogation of the model. In the first project period, the hypothesized feedback regulation from the photorespiratory pathway and the CB cycle could be proven and interactions with other major metabolic pathways shown. In the next period, focus will be on the completion of the multi-level phenotyping studies and the functional dissection of the identified regulatory phenomena.

DFG-Verfahren Forschungsgruppen

Teilprojekt zu FOR 1186:  Photorespiration: Origins and Metabolic Integration in Interacting Compartments