Outer integument cell areas in wild type and KNAT1 misexpressing lines at different stages of development. (A) to (E) Seed coat cell sizes of ovules at the stage of fertilization expressing a fusion between GFP and a membrane-localized protein. (A) Outer integument of wild type ovule. (B) Outer integument of ovule of KNAT1 misexpressing plant. (C) and (D) are optical sections of (A) and (B), respectively. (E) Cell area measurements of o.i.2 cells shows no difference in cell area between wild type (black) and KNAT1 misexpressing (white) plants at this stage. (F) to (J) Seed coat cell area sizes of ovules after fertilization. (F) to (I) Seeds with globular stage embryos. (F) o.i.2 and (H) o.i.1 of line KS149. (G) o.i.2 and (I) o.i.1 of KNAT1 over-expressing plants crossed to line KS149. Cells in the o.i.2 of KNAT1 misexpressing plants are visibly smaller. (J) Ratio of cell area sizes in the o.i.2 versus the o.i.1 of wild type and KNAT1 misexpressing lines at different stages of seed development. Shown are measurements of integument cell areas (n = 25 – 30) of individual developing seeds related to the developmental stage of the embryo. Black squares: wild type. White circles: KNAT1 misexpressing lines. Scalebars: 20 μm, in inserts 100 μm.