Photosynthetic metabolism of C3 plants shows highly cooperative regulation under changing environments: a systems biological analysis.

We studied the robustness of photosynthetic metabolism in the chloroplasts of C(3) plants under drought stress and at high CO(2) concentration conditions by using a method called Minimization of Metabolic Adjustment Dynamic Flux Balance Analysis (M_DFBA). Photosynthetic metabolism in the chloroplasts of C(3) plants applies highly cooperative regulation to minimize the fluctuation of metabolite concentration profiles in the face of transient perturbations. Our work suggests that highly cooperative regulation assures the robustness of the biological system and that there is closer cooperation under perturbation conditions than under normal conditions. This results in minimizing fluctuations in the profiles of metabolite concentrations, which is the key to maintaining a system's function. Our methods help in understanding such phenomena and the mechanisms of robustness for complex metabolic networks in dynamic processes.