Fig. 4. FASS/TON2 is required for correct periclinal divisions in the peripheral endosperm. Confocal sections of seeds from heterozygous fass/ton2 parent plants. (A) Wild-type reference seed with torpedo stage embryo and cellularised endosperm. (B) fass/ton2 mutant seed from same silique as A. (C,D) Details of first periclinal division in the PEN of wild type (C) and fass/ton2 (D). (E) Absence of thin outer cell layer in cellularised PEN in fass/ton2. Scale bars: 100 µm (A,B) and 25 µm (C,D,E).