Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Yantai Institute of China Agricultural University, Yantai 264670, China.
J Hazard Mater. 2023 Aug 15;456:131706. doi: 10.1016/j.jhazmat.2023.131706. Epub 2023 May 24.
The prevalence of antibiotic resistance genes (ARGs) in soils has aroused wide attention. However, the influence of long-term fertilization on the distribution of ARGs in different soil layers and its dominant drivers remain largely unknown. In this study, a total of 203 ARGs were analyzed in greenhouse vegetable soils (0-100 cm from a 13-year field experiment applied with different fertilizers (control, chemical fertilizer, organic manure, and mixed fertilizer). Compared with unfertilized and chemically fertilized soils, manure application significantly increased the abundance and alpha diversity of soil ARGs, where the assembly of ARG communities was strongly driven by stochastic processes. The distribution of ARGs was significantly driven by manure application within 60 cm, while it was insignificantly changed in soil below 60 cm under different fertilization regimes. The inter-correlations of ARGs with mobile genetic elements (MGEs) and microbiota were strengthened in manured soil, indicating manure application posed a higher risk for ARGs diffusion in subsurface soil. Bacteria abundance and MGEs directly influenced ARG abundance and composition, whereas soil depth and manure application indirectly influenced ARG abundance and composition by affecting antibiotics. These results strengthen our understanding of the long-term anthropogenic influence on the vertical distribution of soil ARGs and highlight the ecological risk of ARGs in subsurface soil induced by long-term manure application.
抗生素耐药基因（ARGs）在土壤中的流行引起了广泛关注。然而，长期施肥对不同土层中 ARGs 的分布及其主要驱动因素的影响在很大程度上仍不清楚。在这项研究中，我们分析了温室蔬菜土壤（13 年田间试验中距地面 0-100cm 土层）中 203 个 ARGs，这些土壤分别施加了不同的肥料（对照、化肥、有机肥和混合肥）。与未施肥和化肥施肥土壤相比，有机肥的施用显著增加了土壤 ARGs 的丰度和α多样性，其中 ARG 群落的组装主要受到随机过程的驱动。ARGs 的分布在 60cm 以内主要受到有机肥施用的驱动，而在不同施肥制度下 60cm 以下的土壤中则没有明显变化。在施肥土壤中，ARGs 与移动遗传元件（MGEs）和微生物区系的相关性增强，表明有机肥的施用会增加 ARGs 在亚表层土壤中扩散的风险。细菌丰度和 MGEs 直接影响 ARG 的丰度和组成，而土壤深度和有机肥施用则通过影响抗生素间接影响 ARG 的丰度和组成。这些结果增强了我们对人为因素对土壤 ARGs 垂直分布的长期影响的理解，并强调了长期有机肥施用对亚表层土壤中 ARGs 带来的生态风险。
