GFP expression in line M0237 during seed development. GFP expression marks the long cells of the o.i.2 at the micropylar end of the outer integument. (B) Overlay projection of (A). (C) Overlay projection of mature seed showing persistence of marker gene expression. (D) Cells with distinct identity are located at the distal end of the ovule and seed integuments. Scalebars: 20 μm.