Figure 4.

A, Concentration-dependent kinetics for low-affinity ⁵⁴Mn²⁺ influx in 10-d-old plants of the Mn-efficient barley genotype Vanessa (circle) and the Mn-inefficient barley genotype Antonia (square) at Mn concentrations (10 nm–655 μm). The data were fitted to the Michaelis-Menten equation by nonlinear regression (dashed line). B and C, Calculated saturable uptake kinetics from Vanessa and Antonia, respectively, obtained as described in Figure 3. The kinetics was estimated using the Michaelis-Menten equation (dotted lines). Error bars represent means (n = 4) ± se.