中华苜蓿根瘤菌噬菌体的分离及主要壳蛋白基因g23的系统进化分析

发布时间：2018-06-18 20:08

本文选题：中华苜蓿根瘤菌 + 根瘤菌噬菌体　；参考：《微生物学报》2017年02期

【摘要】：【目的】揭示苜蓿根瘤菌噬菌体的形态学特征及主要壳蛋白g23基因的分布地位,为根瘤菌噬菌体的生态学研究提供数据支持。【方法】以中华苜蓿根瘤菌(Sinorhizobium meliloti USDA1002T)为宿主,采用双层平板法分离土壤环境中的苜蓿根瘤菌噬菌体,利用电子显微镜观察纯化的噬菌体形态特征;提取噬菌体DNA,PCR扩增编码噬菌体壳蛋白的g23基因,构建系统进化树,以形态学鉴定和分子生物学相结合的方法,明确分离获得的苜蓿根瘤菌噬菌体g23基因的系统进化地位。【结果】分离获得了3株噬菌体,头部均呈二十面体,直径大小为81 86 nm,尾部有收缩尾鞘,长度大约为54 70 nm。克隆测序结果显示,获得的3株噬菌体g23基因株间相似度较高,但与可培养的Exo T-、Schizo T-、T-、Pseudo T-evens相似度较低。系统进化分析表明,获得的3株噬菌体不隶属于目前已划分的不同环境噬菌体g23基因的分类类群中。【结论】3株噬菌体均属于肌尾噬菌体科的裂性噬菌体,与目前获得的所有噬菌体g23基因相似性较低,属于新的侵染中华苜蓿根瘤菌的噬菌体株。
[Abstract]:[objective] to reveal the morphological characteristics of alfalfa rhizobia bacteriophage and the distribution of the main shell protein g23 gene, and to provide data support for the ecological study of rhizobia phage. [methods] Sinorhizobium meliloti USDA1002T was used as host. The phage of alfalfa rhizobia in soil environment was isolated by double-layer plate method, the morphological characteristics of purified phage were observed by electron microscope, the G23 gene encoding phage shell protein was amplified by PCR of phage DNA, and the phylogenetic tree was constructed. By means of morphological identification and molecular biology, the phylogenetic position of the G23 gene isolated from Rhizobium sativa was determined. [results] three phages were isolated and showed icosahedron on the head. The diameter is 81 ~ 86 nm, and the tail has a contractile tail sheath with a length of about 54 ~ 70 nm. The results of cloning and sequencing showed that the similarity of the three phage g23 gene strains was high, but the similarity was lower with that of the culturable Exo T-Schizo T-Con T-Pseudo T-evens. Phylogenetic analysis showed that the three phages were not belonging to the classification groups of the g23 gene in different environments. [conclusion] all three phages belong to the cleavage phage of the family Myocystidae. Compared with all the phage g23 genes obtained at present, it belongs to a new phage strain that infects alfalfa rhizobia in China.
【作者单位】：黑龙江八一农垦大学农学院;中国科学院黑土区农业生态重点实验室中国科学院东北地理与农业生态研究所;黑龙江省农业科学院植物脱毒苗木研究所;
【基金】：国家自然科学基金(41301259)~~
【分类号】：Q939.114;Q939.4

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