苜蓿根瘤菌自生与共生状态下核糖体蛋白的比较

Comparison of Ribosomal Protein of Alfalfa Rhizobia(Sinorhizobium meliloti) under Self-Growing and Symbiotic States

苜蓿根瘤菌在与宿主植物建立共生关系的过程中,以自生状态进入宿主植物细胞,经过分化发育转变为共生状态的类菌体(Bacteroid)。由于生存环境发生了变化,类菌体在形态、结构和功能方面都产生了很大的改变,其中最为明显的改变是类菌体获得了共生固氮的能力。此时,类菌体中许多与共生相关的基因被激活,蛋白的表达量显著增加。为了探明这种改变是否与合成蛋白质的细胞器-核糖体有关,比较分析了苜蓿根瘤菌在自生和共生状态下核糖体蛋白的表达谱。蛋白质双向电泳结果显示二者之间没有明显的差别,说明类菌体的分化发育过程中核糖体蛋白的形成没有改变。

During the establishment process of symbiotic relation of alfalfa rhizobium with host plant, alfalfa rhizobium（ Sinorhizobium melitoti） entered into host plant cell as self-growing state, and then transferred into bacteroid of symbiotic state through its differentiation development. Due to the changes of living conditions, its morphology, structure, and function have changed greatly. Among them the most remarkable changes is that it obtains symbiotic nitrogen fixation ability. At the moment, a number of relevant genes in the bacteroid related to the symbiosis were activated, and the expressed quantity of protein remarkably increased. In order to verify whether these changes are correlated to organelle-ribosome of the protein synthesis, protein expression spectrum of ribosome both under selfgrowing and symbiotic states were analyzed by comparison. There is no significant difference between the two states by two-dimensional electrophoresis; therefore, it suggested that the formation of ribosomal protein during the differentiation development process of the bacteroid has not changed.