Xu Lin, Zhang Yong, Wang Li, Chen Weimin, Wei Gehong
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China; Institute of Agricultural and Biological Technology, Hexi University, Zhangye, Gansu 734000, China; Key Laboratory of Western China's Resources and Environment Chemistry, Hexi University, Zhangye, Gansu 734000, China.
Institute of Agricultural and Biological Technology, Hexi University, Zhangye, Gansu 734000, China.
Syst Appl Microbiol. 2014 Sep;37(6):457-65. doi: 10.1016/j.syapm.2014.05.009. Epub 2014 Jun 12.
A total of 201 endophytic root nodule-associated bacteria collected from two legumes indigenous to different Qilian Mountain altitudes (Hexi Corridor) were characterized through 16S rDNA polymerase chain reaction (PCR)-restriction fragment length polymorphism, 16S rRNA gene sequence analysis, and enterobacterial repetitive intergenic consensus-PCR clustering. The isolates phylogenetically belonged to 35 species in the Phyllobacterium, Ensifer, Rhizobium, Microvirga, Sphingomonas, Paracoccus, Mycobacterium, Paenibacillus, Cohnella, Sporosarcina, Bacillus, Staphylococcus, Brevibacterium, Xenophilus, Erwinia, Leclercia, Acinetobacter, and Pseudomonas genera. Phylogenetic nodA sequence analysis showed higher similarity to Sinorhizobium meliloti with strains related to the Rhizobium, Sinorhizobium, and Acinetobacter genera. Sequence analysis of the nifH gene revealed that the strains belonging to Xenophilus, Acinetobacter, Phyllobacterium, and Rhizobium had genes similar to those of Mesorhizobium and Sinorhizobium. The results indicated that horizontal gene transfer could have occurred between rhizobia and non-rhizobial endophytes. Canonical correspondence analysis revealed that altitude and host plant species contributed more to the bacterial endosymbiont separation than other ecological factors. This study provided valuable information on the interactions between symbiotic bacteria, non-symbiotic bacteria and their habitats, and thus provided knowledge on their genetic diversity and ecology.
从祁连山不同海拔高度（河西走廊）的两种豆科植物中总共收集了201株与根瘤相关的内生细菌，通过16S rDNA聚合酶链反应（PCR）-限制性片段长度多态性分析、16S rRNA基因序列分析和肠杆菌重复基因间共有序列-PCR聚类对其进行了表征。这些分离菌株在系统发育上属于叶杆菌属、中华根瘤菌属、根瘤菌属、微小根瘤菌属、鞘氨醇单胞菌属、副球菌属、分枝杆菌属、芽孢杆菌属、考克氏菌属、芽孢八叠球菌属、芽孢杆菌属、葡萄球菌属、短杆菌属、嗜异源菌属、欧文氏菌属、勒克氏菌属、不动杆菌属和假单胞菌属中的35个物种。系统发育nodA序列分析表明，与根瘤菌属、中华根瘤菌属和不动杆菌属相关的菌株与苜蓿中华根瘤菌具有更高的相似性。nifH基因序列分析表明，属于嗜异源菌属、不动杆菌属、叶杆菌属和根瘤菌属的菌株具有与中慢生根瘤菌和中华根瘤菌相似的基因。结果表明，根瘤菌与非根瘤菌内生菌之间可能发生了水平基因转移。典范对应分析表明，海拔高度和宿主植物种类比其他生态因素对细菌内共生体的分离贡献更大。本研究提供了关于共生细菌、非共生细菌及其栖息地之间相互作用的有价值信息，从而提供了关于它们的遗传多样性和生态学的知识。
