
Difficulties in linking the various regulations of nitrate transport acting at different levels of time and on different spatial scales have hindered the development of models for nitrogen uptake. Le Deunff and Malagoli substitute the more usual enzyme–substrate interpretation for a flow–force approach of nitrogen uptake isotherms and combine it with experimentally determined regulation in order to model nitrate in winter oilseed rape, Brassica napus. This approach avoids the use of unique nitrate uptake reference kinetics and allows root plasticity in response to environmental and in planta factors to be taken into account. Furthermore, it allows the regulation of nitrate uptake by roots to be scaled up relatively easily in time from hours to months.