Schmalenberger Achim, Tebbe Christoph C
Institut für Agrarökologie, Bundesforschungsanstalt für Landwirtschaft (FAL), Bundesallee 50, 38116 Braunschweig, Germany.
Can J Microbiol. 2003 Jan;49(1):1-8. doi: 10.1139/w02-111.
In this field study, we compared the bacterial communities inhabiting the rhizosphere of a transgenic, herbicide-resistant sugar beet (Beta vulgaris) cultivar with those of its nonengineered counterpart, using a genetic profiling technique based on PCR amplifications of partial 16S rRNA gene sequences and single-strand conformation polymorphism (SSCP). As a control for the plasticity of the bacterial community, we also analyzed the influence of herbicides, the field heterogeneity, and the annual variation. DNA was isolated from bacterial cell consortia that were directly collected from root material. PCR was carried out with primers that hybridized to evolutionarily conserved regions flanking variable regions 4 and 5 of the 16S rRNA gene. SSCP patterns of these PCR products were composed of approximately 50 distinguishable bands, as detected by silver staining of the gels after electrophoresis. Patterns of the replicates and the different treatments were highly similar, but digital image and similarity analyses revealed differences that corresponded to the positions of the replicates in the field. In addition, communities collected from sugar beet in two successive growing seasons could be distinguished. In contrast, no effect of the transgenic herbicide resistance was detectable. Sequencing of 24 dominant products of the SSCP profiles indicated the presence of bacteria from different phylogenetic groups, with Proteobacteria and members of the Cytophaga-Flavobacterium-Bacteroides group being most abundant.
在这项田间研究中，我们使用基于部分16S rRNA基因序列的PCR扩增和单链构象多态性（SSCP）的遗传分析技术，比较了转基因抗除草剂甜菜（Beta vulgaris）品种根际的细菌群落与其非转基因对照品种根际的细菌群落。作为细菌群落可塑性的对照，我们还分析了除草剂、田间异质性和年度变化的影响。DNA是从直接从根材料中收集的细菌细胞聚集体中分离出来的。使用与16S rRNA基因可变区4和5侧翼的进化保守区域杂交的引物进行PCR。这些PCR产物的SSCP图谱由大约50条可区分的条带组成，通过电泳后凝胶的银染检测到。重复样本和不同处理的图谱高度相似，但数字图像和相似性分析揭示了与田间重复样本位置相对应的差异。此外，在两个连续生长季节从甜菜中收集的群落也可以区分。相比之下，未检测到转基因抗除草剂的影响。对SSCP图谱中24个主要产物的测序表明存在来自不同系统发育组的细菌，其中变形菌门以及噬纤维菌-黄杆菌-拟杆菌群的成员最为丰富。
