蒜鳞片薄壁细胞衰退过程中酶的细胞化学定位及DNA生化分析

蒜在储藏过程中,鳞茎薄壁细胞衰退,其营养物质供给幼芽萌发生长。采用细胞化学方法,对蒜休眠进程中的鳞茎薄壁细胞进行了ATPase以及APase的细胞化学定位,结果显示在薄壁细胞的质膜、细胞壁和胞间连丝上的酶活性随着蒜自休眠至萌发的不同发育进程而呈现增强的趋势,且在萌芽期酶活性表现最为强烈,表明细胞内物质的降解、转化与输出的加强有助于细胞内含物向新生芽的彻底转移。配合采用琼脂糖凝胶电泳对衰退薄壁细胞的DNA进行了分析,实验结果表现出典型的DNA Ladder,为蒜鳞茎薄壁细胞的衰退属于受基因控制的程序性死亡范畴补充了生化证据。

ULTRACYTOCHEMICAL LOCALIZATION OF ENZYMES AND DNA ANALYSIS DURING THE DEVELOPMENT OF GARLIC

It is believed that during storage, the parenchyma cells of garlic (Allium sativum L.) bulb would wither and fade gradually, and nutrients released inside the cells become available for the germination and growth of the young bud. In this study, The distributions of acid phosphatase (APase) and Adenosine Triphosphatase(ATPase) during germination were analyzed based on the method of lead precipitation at the electron microscopic level. It was found that their activities presenting in plasma membrane, cell wall and plasmodesma increased along the different developmental periods during stor- age. The fact that the most intensive enzymatic activity of APase and ATPase appeared at germination indicates that degradation, transformation and exportation of cell matrix are helpful in complete translo- cation of nutrient to new bud. The DNA in the degrading parenchyma cells was analyzed using the agarose electrophoresis. Results clearly showed a typical DNA ladder on the gel, indicating that gene- controlled, programmed cell death may contribute to the degradation of garlic parenchyma cells.