| Under the specific conditions of tissue culture, somatic cells of plant transform into embryonic cells and regenerate entire plants via somatic embryogenesis. As the result of differential expression of embryogenesis-Rela ted genes, the essence of this process has been one of remarkable issues in the plant developmental biology.In this paper, a stable and optimal regeneration system of Aralia elate (Miq.) Seem via somatic embryogenesis was achieved. Aralia elate (Miq.) Seem is a kind of uncultivated vegetable from the mountain Changbai. The process of somatic embryogenesis includes morphogenesis stage of calli, conversion stage of embryonic calli, embryogenetic stage and regeneration stage of plant in Aralia elate(. Miq.) Seem. The embryogenetic stage consists of globular stage, heart stage, torpedo stage and cytoledon stage. The dynamic changes of soluble proteins occurring in aforesaid stages were analyzed by SDS-PAGE. We established a expression model of specific proteins occurring in somatic embryogenesis of Aralia elate (Miq.) Seem on the grounds of the SDS-PAGE result. Furthermore, some embryogenesis-related proteins were found. We also studied the regulation of three factors including plant hormone, activated charcoal and sucrose during somatic embryogenesis of Aralia elate (Miq.) Seem in order to explain the molecular mechanism of somatic embryogenesis.In the light of the expression model, many soluble proteins were expressed dynamically in an specially temporal-spatial sequence. There were two peaks of embryogenesis-related proteins' expression in this model. One corresponded to the period of C6 in which there were some preparations for forming embryonic calli, the other corresponded to the embryogenetic stage.In the conversion of embryonic calli, the lowest threshold value of total protein content in embryonic calli was 11.5+0.5 ug/mg FW. Supposed that the total protein content of calli is beyond or under it, the calli should be nonembryonic calli or the calli with an rather low frequence of somatic embryogenesis. In addition, some soluble proteins occurred respectively in corresponding organs of regenerated plants.Furthermore, we found some embryogenesis-related proteins during somatic embryogenesis of Aralia elate(Miq.)Seem ,which promoted the occur and development of embryoids. firstly, there are five special proteins 49KD,40KD,31KD,22KD,20KD expressing in embryonic calli and embryoge -netic stage. Among them, the protein 49KD expressed in the embryonic call, goluble and mature cytoledon stages, while the protein 31KD in the embryonic calli, goluble and heart stages. They are the molecular markers of embryonic calli and embryogenetic stage correspondingly. Besides, the content of 53KD increased in the embryogenetic stage, which implied that the protein 53KD might contribute to the development of embryoids. Secondly, the proteins of 70KD, 63KD, 55KD,45KD,36KD expressed in morphogenesis stage of calli at first, and continued their expressions in the whole somatic embryogenesis. Among them, the protein 36KD expressed in the period of C6, embryonic calli, embryogenetic stage while not in nonembryonic calli and regenerated plants. It's a crucial protein in the determination of embryonic calli and the development of embryoids. The generation of protein 55KD was regulated by 2,4-D and the protein increased the frequence of somatic embryogenesis obviously. These proteins occurring in primeval periods might be some mutual embryogenesis-related proteins in plant. They played an important role in the determination of embryonic calli. In addition, a specific calli-related protein43KD were found and its expression only occurred in the proliferation of calli. We also found a kind of nonembryonic protein 35KD that expressed in nonembryonic calli and regenerated plants and disappeared in embryonic calli and embryogenetic stage.In a word, every stage in somatic embryogenesis of Aralia elate (Miq.) Seem were completed cooperatively by a group of genes , not by only one gene.Moreover,... |
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