不同浓度砷酸盐胁迫对蜈蚣草根际微生物群落功能多样性特征的影响

发布时间：2018-07-15 19:43

【摘要】：蜈蚣草是世界上第一种被发现的砷超富集植物,其根际微生物对土壤砷的转化及蜈蚣草砷的吸收具有重要影响.采用qPCR和Biolog-Eco微平板法对砷胁迫下蜈蚣草根际微生物群落功能多样性特征的差异进行了研究.首先对蜈蚣草根际微生物的16SrRNA基因丰度进行定量分析;其次,利用Biolog-Eco微平板法分析微生物对31种碳源的平均利用率;同时,通过主成分分析、Shannon多样性指数、Pielou均匀度指数和Simpson优势度指数等探讨了微生物对不同类型碳源利用的差异和砷胁迫对微生物多样性的影响.结果表明,砷胁迫不仅降低16SrRNA基因丰度、减少微生物数量,还会显著影响微生物对碳源的利用效率.其中,微生物对碳水化合物类、氨基酸类和胺类碳源的利用受砷胁迫的影响最显著.此外,砷胁迫会诱导抗砷微生物成为优势群落,结构趋于单一.由于长期暴露可增加蜈蚣草根际微生物的数量,后期研究可深入探讨蜈蚣草根系分泌物中特异碳源物质在强化微生物-蜈蚣草修复砷污染土壤过程中的作用.
[Abstract]:Pteris vittata is the first arsenic superrich plant found in the world. Its rhizosphere microbes play an important role in arsenic transformation in soil and arsenic absorption of Pteris vittata. Using qPCR and Biolog-Eco microplate method, the functional diversity of rhizosphere microbial communities of centipede grass under arsenic stress was studied. The 16s rRNA gene abundance of rhizosphere microbes of Centipede was analyzed quantitatively, and then the average utilization rate of 31 carbon sources was analyzed by Biolog-Eco microplate method. Through principal component analysis, Pielou evenness index and Simpson dominance index of Shannon diversity index were used to study the differences in the utilization of different carbon sources by microorganisms and the effects of arsenic stress on microbial diversity. The results showed that arsenic stress not only reduced the 16s rRNA gene abundance and the number of microorganisms, but also significantly affected the microbial utilization efficiency of carbon source. The use of carbohydrates, amino acids and amines by microbes was most significantly affected by arsenic stress. In addition, arsenic stress can induce arsenic-resistant microorganisms to become dominant communities, and the structure tends to be single. Since long-term exposure can increase the number of rhizosphere microbes in Centipede grass, the role of specific carbon sources in root exudates of Pteris vittata in the process of strengthening microorganism Pteris vittata to repair arsenic contaminated soil can be studied in later stage.
【作者单位】：南京大学环境学院污染控制与资源化国家重点实验室;
【基金】：江苏省博士研究生创新项目(KYLX_0052) 南京大学优秀博士研究生创新能力提升计划B(201601B010)
【分类号】：X17

【相似文献】