The Thermodynamic Flow-Force Interpretation of Root Nutrient Uptake Kinetics: A Powerful Formalism for Agronomic and Phytoplanktonic Models

摘要: The ion influx isotherms obtained by measuring unidirectional across root membranes with radioactive or stable tracers are mostly interpreted enzyme-substrate-like modeling. However, recent analyses from transporter mutants clearly demonstrate the inadequacy of conventional interpretation isotherms. Many genetically distinct carriers involved in catalytic function. Parameters Vmax and Km deduced this cannot therefore be regarded as microscopic parameters a single transporter, but instead macroscopic (V[Formula: see text] K[Formula: text], apparent maximum velocity affinity constant) that depend on weighted activities multiple transporters along root. flow-force based thermodynamic principle irreversible processes is an alternative modeling approach for which Lj (overall conductance system substrate j) πj (thermodynamic parameter when Jj = 0) have straightforward meaning respect to biological sample studied. They characterize efficiency entire structure without deducing molecular characteristics. Here we present basic principles theory how its use can tested improved changing pre- post-wash procedures before measurements order come close possible equilibrium conditions. In addition, constant values Vm Michaelis-Menten (MM) formalism enzyme-substrate do not reflect variations response temperature, nutrient status regimes. linear approach, integrates temperature effect uptake, could usefully replace MM 1-3-dimension models plants phytoplankton. This offers simplification parametrization help find more realistic analytical expressions numerical solution uptake.