Kinetic parameters for low-affinity root Mn^{2+} influx in 10-d-old plants of the barley genotypes Antonia (Mn inefficient) and Vanessa (Mn efficient)

Values for V_{max} and the apparent K_{m} were obtained by fitting calculated data of root Mn influx at external Mn^{2+} concentrations ranging from 10 nm to 655 μm to the Michaelis-Menten equation using nonlinear regression analysis (Fig. 4). Plant characteristics are as in Table I. Values with the same superscript letter were not significantly different between genotypes. The results are presented as average ± 95% confidence limits of four independent regressions (n = 4).