ProNet-CN model: A dynamic and multi-scale process network combining photosynthesis, primary carbon metabolism and effects of leaf nitrogen status

Integrating the hierarchical organization of metabolic and physiological plant processes into crop models is a task that is not solved satisfactorily up to now. To this aim here we present a new multi-scale crop systems biology model. This integrative whole plant modeling framework is based on a complex, hierarchically structured modular process model network considering carbon metabolism and leaf nitrogen status: the ProNet-CN model. ProNet-CN combines the nitrogen sensitive photosynthesis and transpiration model LEAFC3-N with modules describing the dynamics of mass balances of main functional carbon compounds and its allocation between interacting source and sink organs. On this basis, biomass formation of the individual plant organs and of the whole plant is calculated. The Matlab^® Simulink modeling environment was proved to provide an appropriate platform for the development of a system of hierarchically nested dynamic models covering processes at the cellular, organ-based and whole plant level. ProNet-CN was verified and parameterized based on comprehensive data from all process levels considered. Further extension of the nitrogen part of the model and detailed calibration and validation of the model against organ based data on the dynamics of main carbon and nitrogen compounds and on dry mass formation in barley is in progress.