Evaluating photosynthetic performance and photoprotective potential of the TROL-FNR bifurcation
Photosynthesis is arguably the most important autotrophic process on Earth. It provides primary food production and is responsible for the major atmospheric gas exchange. Plants driving photosynthesis consume CO2 and release oxygen that is pivotal for the life of many species. For this, plants require light and water. Being sessile organisms, plants have evolved numerous protective mechanisms against high-light and other stressors. Regulation of the photosynthetic energy flow is in the focus of modern plant biology research and is gaining importance due to rapid climate changes. Final photosynthetic electron transfer to the NADP+ is performed by the enzyme ferredoxin NADP+ oxidoreductase (FNR). In plant chloroplasts FNR binds to thylakoid membranes via protein TROL (Thylakoid RhOdanase-Like), which was previously discovered and characterized by our group. TROL-FNR interaction is dynamic and plays important role in photosynthetic electron partitioning between energy-conserving and -dissipating processes. TROL-bound FNR effectively catalyzes linear electron transfer and NADPH synthesis, while soluble FNR participates in the rapid electron dissipation, which effectively prevents ROS propagation. In this project, we shell research photosynthetic potential of the TROL-FNR bifurcation by using state-of-the-art RACiR gas exchange measurements. Further, we shell investigate the role of this bifurcation in the protective processes of the non-photochemical quenching of chlorophyll a fluorescence (NPQ), ROS propagation, and synthesis of photoprotective molecules.