Fig. 11. Distribution of fluorescent symplasmic tracer in embryo tissues of E2748 and wild type. Optical sections of wild-type (A-C) and mutant (D-F) embryos at the early cotyledon stage. The tissues were incubated with CFDA for 10 minutes (A,D) and 1 hour (B,C,E,F). Arrowheads in A,B and G indicate the boundaries of the outer cell layer and point towards the interior of the cotyledon parenchyma. In mutant embryos the tracer accumulated only in distinct groups of cells (E,F). (G-I) Tissue was treated for 15 minutes with CFDA treatment following a 1-hour chase period without CFDA. Symplasmic tracer (arrowheads) is visible only in the outer region of the wild-type cotyledon (G), whereas in the E2748 mutant small groups of cells inside the parenchyma are labelled (H, arrowheads). (I) A seed of 
200 mg where the embryo was tightly adhered to the inner layers of the seed coats was cut off at the chalazal part without injuring the embryo and the wounded seed coat surface was brought in contact to CFDA. Tracer is present within the seed coat parenchyma (sc p) and the endospermal tissue (en) but not within embryonic tissue (e) which appears as a black layer. Scale bars: 200 µm (A,B,D,E); 1 mm (C,F).
