Abstract
The first step in the mobilization of the reserves in germinating rice seed was the decomposition of amylopllast envelopes in endosperm cells adjacent to scutellum.Destruction of amyloplast envelopes caused the separation of the starch granules.Small holes appeared on the surface of the released starch granule adjacent to scutellum at 3 days after imbibition(DAI).At later stages, the number and size of the holes increased on the surface of the starch granule.Ring-like structure in the interior of starch granule was recognized in endosperm cell adjacent to scutellum at 6 DAI.Like this structure appeared in the starch granule at the central part and at the top part of endosperm at 7 and 14 DAI respectively.At 18 DAI, the remaining starch granules became smaller in size and were covered with high-viscosity materials assumed to be soluble polysaccharides.Transmission electron microscopy showed that the intact starch granules were enveloped tightly within the amyloplast membrane.When the amyloplast was degraded, the exterior of the starch granules also started to decompose.The starch granules were decomposed from the exterior rather than the interior.
