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Integrative metabolic modelling predicts water-saving flux modes in leaf metabolism.


Modelling and analysis of CAM and C4 photosynthesis

Plants perform photosynthesis to transduce light energy into chemical energy which is used to power the assimilation of carbon and nitrogen from the environment and to ultimately enable plant growth and reproduction. About 85 % of all plant species perform C3 photosynthesis in which CO2 is directly fixed by Calvin-Benson-Basham cycle enzyme rubisco. However, this process is accompanied by photorespiration, a wasteful pathway that occurs when the rubisco fixes O2 rather than CO2. C4 and CAM photosynthesis have evolved as heat and drought resistant alternatives to C3 photosynthesis. They rely on spatial or temporal separation of initial carbon fixation and re-fixation by rubisco and thereby reduce photorespiration and increase water-use efficiency. We use large-scale metabolic models to better understand the energetics, metabolic and anatomical constraints of C4 and CAM photosynthesis and to ultimately identify engineering targets for improved future crops. On a related note, we are also engaged in computational modelling of the energetics of guard cell metabolism. Guard cells control stomatal opening and thus the water-gas exchange at the leaf surface.

Further reading:

Töpfer N (2021) Environment-coupled models of leaf metabolism. Biochemical Society Transactions,

Töpfer N, Braam T, Shameer S, Ratcliffe RG, Sweetlove LJ (2020) Alternative Crassulacean Acid Metabolism Modes Provide Environment-Specific Water-Saving Benefits in a Leaf Metabolic Model. The Plant Cell,