Abstract
In some dicot plants, such as the crucifers Arabidopsis, the pattern of cell division during early embryogenesis is fixed and the cell fate is traceable. On the other hand, in cotton and grasses such as rice, variant cell division occurs during embryogenesis. These indicate that there is no universal pattern of early cell cleavages that describes embryonic development. On the other hand, it has been known that IAA plays essential roles on Arabidopsis embryogenesis even from two-cell stage. In the present study, we carefully observed early developmental pattern of rice embryo. In zygote, cell plate was slantly formed against micropylar-chalazal axis. Two-celled embryo was seemed to divide into four-celled embryo with cell cleavage vertical to first cell division plane of zygote. The four-celled embryo was further developed into globular and differentiated embryos. IAA distributions in rice embryo using immunocytochemical approach with anti- PIN antibodies are under investigation.
