Figure 7.

Mobilization of Iron between Leaves Is Impaired in opt3-2.

(A) ⁵⁹Fe was applied to a mature wild-type or opt3-2 leaf and the distribution of ⁵⁹Fe was monitored after a 12-h incubation period. Lower panel: Signal coming from ⁵⁹Fe was detected in wild-type leaves adjacent to the leaf where the ⁵⁹Fe was applied while only a fraction of the signal was detected in opt3-2 leaves.

(B) The specific activity measured in the four adjacent leaves to which the ⁵⁹Fe was originally applied show that the movement of ⁵⁹Fe in opt3-2 was marginal. Data represent mean ± SE (n = 4, * p < 0.05).

(C–I) Visualization of Fe using Perls’ stain shows that, compared to a mature wild-type leaf (C), opt3-2 contains substantial amounts of stainable Fe (D). (E) Over-accumulation of Fe in opt3-2 leaves is less evident in younger leaves. Accumulation of Fe in opt3-2 leaves is more evident close to (F) secondary veins, (G) the base of trhichomes, and (H, I) surrounding the vasculature.