摘要
本研究根据植物细胞的特点,修改了在动物和人体细胞方面建立的酶标Con A的电镜细胞化学方法,成功地展现了冬小麦(Triticum aesti vum L.)幼叶细胞膜系统上糖蛋白的分布状况。揭示在适宜温度生长条件下,标志糖蛋白存在的辣根过氧化物酶活性的反应产物成颗粒状分散分布在质膜、内质网、核膜及液泡膜上。在经过秋末冬初低温锻炼后的麦苗细胞内,糖蛋白在内质网和核膜上的分布量明显地增加;同时,在几乎所有观察到的胞间连丝中都存在糖蛋白的分布;并在线粒体膜和质体膜上出现一些糖蛋白的位点。然而在整个观察中始终未能观察到高尔基体上有糖蛋白的存在。作者讨论了低温锻炼中糖蛋白输入胞间连丝在提高和稳定植物抗寒力上的作用,以及高等植物细胞内糖蛋白的合成地点和运输途径与动物细胞可能存在的差异。
The localization and distribution of the glycoproteins in cellular membranes of strong cold hardy winter wheat (Triticum aestivum L.cv.Yanda 1817) seedlings were studied employing the modified cytochemical method using Concanavalin A-Horseradish peroxidase conjugates.The results obtained showed that the reaction products of Horseradish peroxidase activity which indicated the presence of glycoproteins appeared as individual particles distributed at plasmalemma,endoplasmic reticulum,nuclear envelope and tonoplast in the leaflet cells of the seedlings grown under optimum temperature 25℃ day/20℃ night.After cold acclimation of the seedlings at low temperature during late autumn and early winter,the quantity of glycoproteins distributed in endoplasmic reticulum and nuclear envelope was significantly increased,and glycoproteins were transported into almost all of the plasmodesmata. At some sites of mitochondria and plastides newly formed glycoproteins were observed.However, no distribution of glycoproteins was found in Golgi bodies during the whole observations. The role of glycoproteins for the development and stability of cold resistance in plant through blocking up the plasmodesma passage in the overwintering period of winter wheat seedlings,and the possible differences of the synthetic site and transportation pathway of glycoproteins between animal and plant systems were discussed.
基金
国家自然科学基金资助项目
关键词
小麦
糖蛋白
细胞膜
细胞化学
Glycoprotein
Membrane
Cytochemistry
Ultrastructure
wheat
Plant cold hardiness
