Figure 8.

OPT3 Mediates Xylem-to-Phloem Fe Transfer.

(A) and (B) The concentration of Fe and K in phloem sap (A) or Fe and Cd in xylem sap (B), both collected from wild-type and opt3-3 mutant plants grown hydroponically under Fe-sufficient conditions. Error bars represent se (n = 3). Asterisks indicate statistically significant differences (*P ≤ 0.05 and **P ≤ 0.001).

(C) Synchrotron x-ray fluorescence map of Fe distribution in leaves of the wild type and the opt3-3 mutant in Arabidopsis. Note that the line of Fe in the leaf of the wild type is an artifact of the leaf folding. Bar = 1 mm.