摘要
取经过预培养的烟草(Nicotiana tobacum L.)茎表层3—4层细胞,切成10×3mm 大小的外植体,厚度为30—40μm,进行微室培养,成功地建立了能进行活体定位连续观察的细胞薄层培养实验系统。通过活体连续观察,结合 DNA 活体测量,发现烟草表皮细胞在培养24小时后,核明显增大,核质变浓,DNA 含量显著增加,细胞质变浓厚,运动加速,细胞器也随之加速运动。通过这些变化,细胞完成了脱分化,回到了细胞周期的间期,并开始进行有丝分裂。
Explants were obtained by excising cortical tissue from stems of precultured Nicotiana tabacum in 3×10 mm strips,containing 3～4 cell layers,and thickness of which was 30～40μm. Using modified microculture method,a successful experimental system that could be used for positioned sequential observation in vivo was established.Through continued observation in vivo and using microspectrophotometer technique,we found that,after 24 h culture of explants, nuclei in tabacco epidermal dells enlarged and their DNA contents increased,the density wi- thin the nuclei and cytoplasm also increased,cytoplasm and organelles in them moved faster. Thraugh these changes the cell dedifferentiation was completed,epidermal cells returned to interphase,ready for mitosis.
关键词
烟草
薄层培养
表皮细胞
Epidermal cell
Thin layer culture
Dedifferentiation
Nicotiana tabacumL
