Abstract:Developmental changes of rice (Oryza sativa, subsp, japonica) in embryonic proteins during embryogenesis were investigated by modified two-dimensionalpolyacrylamide gel electrophoresis. The results indicated that there were apparently differences in the embryonic proteins between the embryos at 7th and 13th day after anthesis. Some proteins only appeared in the embryos al 7th day, disappearing at 13th day. Then some new proteinsappeared at 21th day embryos, which were different from that disappeared during differentiation. In concomitant with the completion of embryo differentiation, the number of acidic proteins decreased, while the basic ones showed an increasing trend. Itwas also found that in the 7th day embryos, there were a higher relative percent ofembryonic protein spots in the region of higher molecular weight, while in the 13thday there were higher relative percent of ones in the region of lower molecular weight.The electrophoretic pattern of rice germ lectin (RGL) showed that the synthesis ofRGL was associated with embryo differentiation. According to these results, we propose that some of embryonic proteins which areonly found at early stage of embryogenesis may be important factors for the regulationof embryo differentiation. Although the function of these proteins is still an openquestion, these specific proteins, at least, represent an excellent mark for plant embryodifferentiation.