黄瓜韧皮部的类血影蛋白(英文)

Spectrin-like Protein in the Phloem of Cucumis sativus

以黄瓜 (CucumissativusL .)叶柄为实验材料 ,应用胶体金免疫电镜技术证明类血影蛋白存在于韧皮部的筛管_伴胞复合体中 ,广泛分布于筛分子中的韧皮蛋白纤丝以及筛分子网络结构上 ,并且分布在伴胞的细胞质和线粒体膜以及筛分子与伴胞之间的分支状胞间连丝上 ,表明该蛋白可能由伴胞合成并经由二者之间的胞间连丝运输到筛分子中。用免疫印迹技术证明 ,黄瓜韧皮部汁液蛋白中存在类血影蛋白 ,其分子量约为 2 6 0kD 。

Spectrin-like protein has been found in a variety of plant cells. In this study, electron microscopic observation of immuno-gold labelled preparations from the leaf petiole of cucumber ( Cucumis sativus L.) shows that it also exists in the sieve element-companion cell (SE-CC) complex, being widely distributed in P-protein filaments and sieve element reticulum (SER), in the cytoplasm and mitochondrial membrane of companion cell (CC) and in the branched plasmodesmata between sieve element (SE) and CC as well. The results suggest that this protein could be synthesized in CC and transferred to SE through plasmodesmata. Western blotting showed that spectrin-like protein existed in the protein of phloem exudate of cucumber, and its molecular weight was about 260 kD.