摘要
采用细胞化学方法 ,研究了黄瓜种子中贮藏Ca2 + 的分布特点及其在萌发过程中的变化动态。干种子的子叶细胞中贮藏有大量的蛋白体、油脂体 ,Ca2 + 沉淀颗粒大量分布于胞质、胞间隙以及细胞质膜上。大多数蛋白体中有 1至数个圆球形或椭圆体形含Ca2 + 的球状晶体。相比之下 ,胚芽和胚根细胞中Ca2 +较少。种子萌发早期 ,子叶中的贮藏钙及晶体溶解释放出的Ca2 + 部分转运到生长发育中的胚芽和胚根中。随着萌发的继续 ,胚根和胚芽细胞中的Ca2 + 不会持续增多 。
The changes in subcellular localization of Ca 2+ and the ultrastructure during germination of Cucumis sativus L. (Jinza #2) seeds were studied by cytochemical method and electron microscopy. Electron dense Ca 2+ antimonate deposits were mostly localized in cytoplasm, intercellular space and matrix of protein bodies of cotyledon cells of dry seeds (Plate I 1,2). The globoid crystals of protein bodies were also the major Ca 2+ stores. By contrast, there were few Ca 2+ deposits in the radicles or the plumules of dry seeds (Plate I 3,7). After 1 d of germination, the Ca 2+ content in cotyledons decreased slightly, and the Ca 2+ in globoid crystals was found to be released into the cytoplasm (Plate II 1,2). Meanwhile, large amounts of Ca 2+ antimonate deposits appeared in the cells of radicles and plumules (Plate II 3,6). However, after 2 d of germination, Ca 2+ antimonate deposits in the cells of radicles and plumules also decreased (Plate III 4,6). The possible role of Ca 2+ in seed germination was discussed.
基金
湖北省自然科学基金 (99J0 84)资助
关键词
黄瓜
种子萌发
Ca^2+分布
Cucumis sativus L., seeds, germination, Ca 2+
