Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China.
University of the Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
FEMS Microbiol Ecol. 2020 Apr 1;96(4). doi: 10.1093/femsec/fiaa037.
Animal bodies are colonized by many microorganisms which can provide indispensable services to their hosts. Although nematode gut microbiota has been extensively studied in recent years, the driving factors of gut microbiome of soil nematodes from a long-term fertilization field are unclear. Here, using 16S rRNA gene amplicon sequencing, we explored the nematode gut microbiota under different fertilization patterns (control, inorganic fertilizers and mixed fertilizers) and fertilization durations (5 y, 8 y and 10 y). Our results revealed that nematode gut microbiota was dominated by core bacterial taxa AF502208 (anaerobic bacteria), Enterobacter (plant litter decomposition) and Ancylobacter (organic matter decomposition and nitrogen cycling), significantly distinct from soil microbiome, and the assembly of that was a non-random process, which suggested host conditions contributed to maintaining the gut microbiota. Moreover, fertilization pattern had a greater influence on nematode gut microbiome than fertilization duration. Inorganic fertilization (5.19) significantly reduced the diversity of the nematode gut microbiota (6.68) shown by Shannon index (P < 0.05). Canonical correspondence analysis demonstrates that soil properties such as pH, organic matter, total phosphorus, available phosphorus, ammonium nitrogen, moisture content, nitrate nitrogen and total nitrogen have significant effects on the nematode microbiome. Structured equation models further revealed that fertilization could obviously affect the nematode gut microbiota, and the effects were maintained even when accounting simultaneously for the drivers of soil bacteria and soil properties. This study provides a solid evidence that the shifting of nematode gut microbiota under long-term fertilization was resulted from environmental factors and host conditions, and advance the insights into host-microbiome in the agricultural ecosystems.
动物体内定植着许多微生物，这些微生物可以为宿主提供不可或缺的服务。尽管近年来人们对线虫肠道微生物群进行了广泛的研究，但长期施肥条件下土壤线虫肠道微生物组的驱动因素尚不清楚。在这里，我们使用 16S rRNA 基因扩增子测序技术，研究了不同施肥模式（对照、无机肥和混肥）和施肥时间（5 年、8 年和 10 年）下线虫肠道微生物群。研究结果表明，线虫肠道微生物群主要由核心细菌分类群 AF502208（厌氧菌）、肠杆菌（植物凋落物分解）和Ancylobacter（有机质分解和氮循环）组成，与土壤微生物群明显不同，其组装是一个非随机过程，这表明宿主条件有助于维持肠道微生物群。此外，施肥模式对线虫肠道微生物群的影响大于施肥时间。无机施肥（5.19）显著降低了线虫肠道微生物群的多样性（6.68），表现为 Shannon 指数（P < 0.05）。典范对应分析表明，土壤性质如 pH 值、有机质、总磷、有效磷、铵态氮、含水量、硝态氮和总氮对线虫微生物群有显著影响。结构方程模型进一步表明，施肥可以明显影响线虫肠道微生物群，即使同时考虑土壤细菌和土壤性质的驱动因素也是如此。本研究提供了确凿的证据，证明长期施肥下线虫肠道微生物群的转移是由环境因素和宿主条件共同作用的结果，并深入了解了农业生态系统中的宿主-微生物组。
