Movie S1.

z-stack of the wild-type seed shown in Fig. 6A, with embryo at 2/4-cell stage. The endosperm and chalazal cyst are normal. The seed was Feulgen stained and imaged under a confocal microscope. Optical sections were acquired at 0.5-nm intervals covering the seed cavity. The movie was created from a z-stack of 40 optical sections. Scale bar is 40 μm.