Figure 3.

⁵⁹Fe influx rate of Fe-deficient leaves detected by live-autoradiography. (a) Scheme for calculation of ⁵⁹Fe influx rate to leaves. Three regions of interest (ROIs) of 16 mm² (4 mm × 4 mm = 5 × 5 pixels) were set for each leaf, and average values of the three ROIs were calculated. Time–activity curves (TACs) for ⁵⁹Fe Bq per 16 mm² of each leaf were then generated. ⁵⁹Fe influx rate was calculated from the increase of radioactivity during a time window (120–210 min) when activity was linearly increased. (b) ⁵⁹Fe influx rate of each leaf was measured using three plants of each cultivar. Each TAC is represented in Figure S2. Only Fe-deficient leaves are represented, since the ⁵⁹Fe influx rates of control leaves were slow and sometimes undetectable. Gray bars, SRB; blue bars, EHM; orange bars, ETH. * p < 0.05 and ** p < 0.01 indicate significant differences (according to Student’s t-test) between the two cultivars.