Comparison of the Rhizosphere Bacterial Communities of Zigongdongdou Soybean and a High-Methionine Transgenic Line of This Cultivar

Previous studies have shown that methionine from root exudates affects the rhizosphere bacterial population involved in soil nitrogen fixation. A transgenic line of Zigongdongdou soybean cultivar (ZD91) that expresses Arabidopsis cystathionine γ-synthase resulting in an increased methionine production was examined for its influence to the rhizosphere bacterial population. Using 16S rRNA gene-based pyrosequencing analysis of the V4 region and DNA extracted from bacterial consortia collected from the rhizosphere of soybean plants grown in an agricultural field at the pod-setting stage, we characterized the populational structure of the bacterial community involved. In total, 87,267 sequences (approximately 10,908 per sample) were analyzed. We found that Acidobacteria, Proteobacteria, Bacteroidetes, Actinobacteria, Chloroflexi, Planctomycetes, Gemmatimonadetes, Firmicutes, and Verrucomicrobia constitute the dominant taxonomic groups in either the ZD91 transgenic line or parental cultivar ZD, and that there was no statistically significant difference in the rhizosphere bacterial community structure between the two cultivars.

已有研究表明，根系分泌物中的甲硫氨酸会影响参与土壤固氮过程的根际细菌种群。本研究针对表达拟南芥胱硫醚γ合酶、可提升甲硫氨酸产量的自贡冬豆转基因株系ZD91，探究其对根际细菌种群的影响。研究采集农业大田种植下结荚期大豆根际的细菌群落DNA，采用基于16S核糖体RNA（16S rRNA）基因V4区的焦磷酸测序技术进行分析，以此解析相关细菌群落的种群结构。本次研究共分析了87267条序列（单样本约10908条）。结果显示，在ZD91转基因株系及其亲本栽培品种ZD的根际土壤中，酸杆菌门（Acidobacteria）、变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）、放线菌门（Actinobacteria）、绿弯菌门（Chloroflexi）、浮霉菌门（Planctomycetes）、芽单胞菌门（Gemmatimonadetes）、厚壁菌门（Firmicutes）以及疣微菌门（Verrucomicrobia）均为优势分类类群；且两个栽培品种的根际细菌群落结构无统计学显著差异。