Modeling non-stationary conditions for carbohydrate compartmentation and export in maize leaf

Distribution of photosynthetic carbon, in an exporting maize leaf (Zea mays), was modeled from the analysis of radioactivity chase experiments after a ¹⁴CO₂ pulse labeling. A model taking into account four compartments -precursor pool, starch pool and two exchangeable sucrose pools- was proposed. It brought significant improvements compared to earlier attempts in that it allowed direct calculation for all of the compartment sizes and transfer coefficients, without any additional simplifying hypothesis. This more comprehensive version was used to test the influence of various procedures or assumptions frequently chosen when performing compartmental analysis with an exporting leaf. Most of the calculations appeared to be dependent on a good estimate of the asymptote value, so a critical point appeared to be the length of the chase period