Developmental pathway and protein changes of somatic embryogenesis in E. sativa mill

Somatic embryos were induced from cotyledon explants cultured on MS medium supplemented with 1.0 mg·L^-1 2,4-D. Morphological and protein changes were performed aiming at the developmental process of somatic embryogenesis of E. sativa. The observation revealed that the embryos pass through the characteristic globular, heart, torpedo, and cotyledon stages. The developmental process of the somatic embryo is similar to that of the zygotic embryo. The results showed there was a decrease in the protein content between the 0 and 14 d of culture on medium with 1.0 mg·L^-1 2, 4-D. The protein content of somatic embryos grown on N6 hormone-free medium was distinctly higher than that on the medium supplemented with 1.0 mg·L^-1 2,4-D. SDS-PAGE of protein patterns showed specific protein bands with changed staining density. The content of 18 KD proteins was decreased after culture on medium with 1.0 mg·L^-1 2, 4-D. On N6 hormone-free medium, protein bands of 65 KD, 68 KD and 70 KD were observed.