Simulation of Photosynthesis and Analysis of Plant Productivity

Photosynthesis is a basis of plant productivity; this makes it extremely important to develop methods for its assessment and forecasting under various environmental conditions. At the same time, the complexity of photosynthetic processes and the presence of numerous feedbacks require the development of mathematical modeling and other complex approaches to its analysis. This review describes mathematical models of photosynthetic processes at different levels (from processes in thylakoid membranes to the whole plant and ecosystem) and analyzes potential ways of their application for studies of the plant productivity. First, models describing the activity of photosynthetic reaction centers are firstly considered. These models are widely used for analysis of experimental data for estimation of physiological state and productivity of plants. The next group of models focuses on describing the photochemical processes at light reactions of photosynthesis. These models can be used for analysis of experimental data as well as for prediction of damage of photosynthetic machinery under conditions of rapid changes in environmental conditions (e.g., fluctuations in light intensity). The models, which consider photosynthetic dark reactions, are based on either descriptions of processes that limit CO2 assimilation or description of reactions of the Calvin-Benson cycle. Models of this group can be used for simple description of the plant productivity. More complex photosynthetic models can also consider distribution of light intensity and CO2 fluxes in leaves, as well as interactions of photosynthethesis with other physiological processes. These models can be used for prediction of the plant productivity under different environmental conditions or at artificial modifications of the photosynthetic machinery. The review also analyzes "supraorganism" photosynthetic models, which are based on simple descriptions of photosynthetic processes and can be used to analyze productivity at the level of vegetative cover and natural or artificial ecosystems. In general, numerous mathematical models of photosynthesis at various levels are aimed at solving a wide range of basic and practical problems. In particular, they can potentially be used to assess disturbances in crop productivity under unstable growing conditions or to optimize productivity under stable protected ground conditions. A promising direction of photosynthetic modeling is the development of simulation medium integrating individual models of various levels for solution of specific tasks.