Fe distribution in fer and irt1 mutant plants. (A) Semi-thin (1 μm) longitudinal sections of Perls/DAB stained root tips of wild-type seedlings after transfer from + Pi to + Pi or –Pi (20 h). Shown are overview (scale bar 100 μm) and detail (scale bar 25 μm) images of the root tip. Arrows indicate punctate Fe storages. (B) Perls/DAB Fe staining of wild-type and irt1 seedlings. Upper and middle panels show mature and young differentiated root segments, respectively. Lower panels show the root meristem. Scale bar 100 μm. (PDF 1598 kb)