萝卜愈伤细胞凋亡的初步研究

Preliminary Study on Callus Apoptosis in Radish

[目的]探明萝卜无菌苗组织培养过程中愈伤组织细胞凋亡的形态变化。[方法]以萝卜种子为材料,通过组织培养获得无菌苗和诱导出愈伤组织,利用离子胁迫诱导愈伤组织的细胞凋亡,并对其样品进行组织制片,染色后用光学显微镜观察与电镜超薄切片观察萝卜愈伤组织凋亡形态变化。[结果]在萝卜的细胞凋亡过程中存在和动物细胞凋亡类似的染色质浓缩、颗粒化和边缘化以及后期发生降解形成凋亡小体等现象。钠离子和钙离子对萝卜愈伤组织细胞凋亡的影响程度不同,钠离子影响不大,而钙离子对细胞凋亡影响较明显,且随着离子浓度的增加,凋亡所需时间越短。[结论]细胞凋亡的过程往往伴随染色质DNA的特异性断裂,形成寡聚核苷酸片段,电泳后形成DNA梯形带。

[ Objective ] The research aimed to prove up the morphological change of callus apoptosis during the tissue culture process of asepsis seedlings in radish. [ Method ] With the radish seeds as the tested material, the asepsis seedlings were obtained and callus were induced through tissue culture. The ion stress was used to induce the callus apoptosis, its sample was made into slices, after staining their morphology change of radish callus were observed with optical microscope and ultra-thin section in electron microscopy. [ Result ] There were some phenomena such as the ehromatin condensation, granulation, marginalization and apoptosis bodies formed in anaphase degradation during the radish apoptosis process, which was similar to the animal apoptosis. The natrium and calcium ions had effects on radish callus apoptosis to different degree. The natrium ion had less effect on the callus apoptosis. The calcium ion had obvious effect on radish callus apoptosis and its apoptosis time needed was shorter with increment of ion conen. [ Conclusion ] The radish callus apoptosis process often accompanied the special fracture of chromatin DNA, which formed oligonueleotide segment and then formed DNA ladder after eleetrophoresis.