水稻及其他禾本科植物体内硅结合蛋白的免疫印迹检测

Immunoblot Detection of Silica-binding Protein in Rice and Other Graminaceous Plants

为了检测硅结合蛋白在水稻和禾本科植物体内的分布,根据硅结合蛋白(silica-binding protein 117,SBP117)的氨基酸保守片段和天然抗原表位,合成了SBP117的两个肽段做抗原,与匙孔血蓝蛋白载体偶联后免疫兔子,获得了抗SBP117的专一性抗体. 蛋白质印迹和免疫印迹检测表明,SBP117的抗体不仅能识别水稻硅结合蛋白,而且与其他累积硅的禾本科植物中提取的硅结合蛋白有交叉反应,但它不识别不累积硅的双子叶植物番茄叶中的蛋白质以及牛血清蛋白,说明与SBP117同源的硅结合蛋白广泛存在于禾本科植物之中. 组织印迹法定位显示,SBP117主要分布在水稻根茎叶的外表皮中,在根和叶的维管组织中也有分布,这与前人报道的硅在水稻体内的分布是一致的,说明此蛋白质可能参与到诱导和控制硅在植物体内的沉积.

In order to detect the distribution of silica-binding proteins in rice and other graminaceous plants, specific polyclonal antibodies against a silica-binding protein from rice, namely SBP117, are successfully raised by synthesized peptides which are conjugated with Keyhole Limpet Hemocyanin and used as antigens to immunize rabbits. Western blot and the immunoblot results indicate that the antibodies not only can react with silicon-binding proteins of rice, but also can cross react with the proteins of other silicon-accumulated graminaceous plants, while it does not react with the proteins of non-silicon accumulated dicotyledonous plants (such as tomato leaves) and BSA. These findings indicate that the homologous proteins of SBP 117 are widely existed in the graminaceous plants. Furthermore, tissue printing study shows that SBP117 is mainly located at the epidermis of roots, shoots and leaves as well as in the vascular bundle of the rice roots and leaves. The distribution of SBP117 in rice plants is coincided with the sites of Si accumulation in rice reported previously. Therefore it is concluded that the silicon-binding protein (SBP117) may be involved in the control of silicon deposition in rice plants.