Fig. 7

The late embryo development of V. planifolia. a As the seed approached maturity, a number of tiny protein bodies (arrows) appeared within the embryo proper cells after amido black 10B stain. The thickened outer seed coat (OS) became dehydrated and compressed, with the inner seed coat (IS) compressed into a thin layer. b Light micrograph showing a longitudinal section through a mature seed. Several tiny protein bodies (arrows) were found within the embryo proper cells. In this preparation, the lipid bodies were not preserved; the spaces (arrowheads) between the protein bodies were occupied by storage lipid bodies. c Nile red staining fluorescence micrograph of an early globular embryo at the stage similar to Fig. 3E. After Nile red staining, the surface wall of the embryo proper (arrows) reacted weakly to the stain, and the innermost (arrowhead) and outermost (double arrowhead) walls of the inner seed coat also reacted positively. d Nile red staining fluorescence micrograph of a mature seed at the stage similar to Fig. 5B. The inner seed coat compressed into a thin layer and attached the embryo tightly. The thin inner seed coat (IS, arrowheads) and the surface of the embryo proper (arrow) reacted positively to the stain. Fluorescence was never observed in the thickened outer seed coat (OS). Scale bar = 100 μm