Uptake of aluminum into root cytoplasm: Predicted rates for important solution complexes

In this report we predict the rate of aluminum absorption into root cytoplasm as solutes that are common in acid soil solutions. Our predictions of passive influx rely upon permeability coefficients estimated from known values for similar compounds. We also consider aluminum absorption by endocytosis and absorption by competition with iron for iron‐specific transport mechanisms. Our calculations indicate that passive flux of Al³⁺ or of common charged Al‐complexes is unlikely to contribute measurably to total aluminum absorption , but endocytosis of Al³⁺ bound to the plasma membrane surface may dominate uptake under some conditions. Among neutral Al‐complexes, AlF₃ ^o absorption should be detectable; by comparison, passive influx by Al‐citrate^o should not be detectable.