红豆草胚性细胞系和非胚性细胞系DNA代谢动态的研究

以红豆草无菌苗胚轴为外植体诱导愈伤组织,在此基础上建立了“胚性细胞系”和“非胚性细胞系”。应用放射自显影方法研究了这两种细胞系的DNA合成动态,結果表明:前者DNA合成十分活跃,且DNA合成只限于发生胚的单细胞和细胞群。这些细胞迅速分裂,分别发育形成不同阶段的体细胞胚,在这一过程中,DNA代谢呈现有规律的变化,到球形胚时,DNA合成速率达到最高峰。体细胞胚中各细胞DNA合成速率的差异与体细胞胚形态学极性存在明显的相关性。至于“非胚性细胞系”,在启动分裂和形成愈伤组织过程中也是以细胞DNA复制为基础的,但在该类细胞系中,无论是DNA合成速率还是~3H-胸苷标记的细胞频率都远低于胚性细胞系。DNA代谢动态在这两类细胞系中存在着明显的差异。

THE STUDIES OF DNA METABOLIC DYNAMICS IN EMBRYONIC CELL LINE AND NON-EMBRYONIC CELL LINE OF Onobrychis viciaefolia Scop.

The hypocotyls of aseptic seedlings of Onobrychis viciaefolia Scop.were used as explants for inducing callus.The embryonic cell line ( E-line) and non-embryonic cell line (NE line) were established.The DNA synthesis dynamics in both cell lines were studied by autoradiography.The results showed that:DNA synthesis in E-line was active and confined to embryonic cell or cell masses and then the cells divided quickly and formed somatic embryos at different stages.The changes of DNA metabolism took place in a certain pattern and the maximum rate of DNA synthesis occured during the formation of globular embryo.There was a clear relationship between the difference of DNA synthesis rate and the polarity of the embryo.In NE-line,the beginning of cell division and the forming of callus were also based on DNA replication but were much lower in the DNA synthesis rate and the number of labelled cells of 3H-deoxythymidine.There was a significant difference in DNA.synthesis dynamics between the two cell lines.