State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
Sci Total Environ. 2023 Aug 15;886:163933. doi: 10.1016/j.scitotenv.2023.163933. Epub 2023 May 8.
Soil microorganisms carrying antibiotic resistance genes (ARGs) can colonize plants as endophytes, posing a huge risk to human health. However, the distribution and transmission patterns of ARGs in different soil-plant systems are unclear. Here, we investigated the distribution of ARGs and the microbial communities in the soil-wheat and soil-cucumber systems by quantitative PCR (qPCR) and 16S rRNA gene sequencing. The results showed that the relative abundances of seven ARGs and intI1 in roots were higher than those of other samples in both soil-plant systems. Pseudomonas, Enterobacteriaceae, Rhizobiales and Gammaproteobacteria were dominant potential bacterial hosts of endophytic ARGs, with enrichment patterns similar to that of ARGs in roots. In addition, more ARGs were significantly positively correlated with intI1 in roots, indicating that ARGs may be more prone to horizontal gene transfer (HGT). Variation partitioning analysis (VPA) and structural equation models (SEM) revealed that the variations of ARGs were mainly directly affected by the HGT of intI1 and indirectly affected by soil properties in roots. These results demonstrated that root could have a strong proliferative effect on ARGs entering host plant endophytes. Overall, our findings enhanced the understanding distribution patterns of ARGs in different soil-plant systems, and provided an effective basis for developing measures to minimize the spread of ARGs.
携带抗生素抗性基因 (ARGs) 的土壤微生物可以作为内生菌定植于植物中，对人类健康构成巨大威胁。然而，不同土壤-植物系统中 ARGs 的分布和传播模式尚不清楚。在这里，我们通过定量 PCR (qPCR) 和 16S rRNA 基因测序研究了土壤-小麦和土壤-黄瓜系统中 ARGs 和微生物群落的分布。结果表明，在这两种土壤-植物系统中，根中七种 ARGs 和 intI1 的相对丰度均高于其他样本。假单胞菌、肠杆菌科、根瘤菌目和γ-变形菌门是内生 ARGs 的主要潜在细菌宿主，其富集模式与根中 ARGs 相似。此外，更多的 ARGs 与根中 intI1 呈显著正相关，表明 ARGs 可能更容易发生水平基因转移 (HGT)。方差分解分析 (VPA) 和结构方程模型 (SEM) 表明，ARGs 的变化主要直接受 intI1 的 HGT 影响，间接受根中土壤特性的影响。这些结果表明，根可能对进入宿主植物内生菌的 ARGs 具有强烈的增殖作用。总的来说，我们的研究结果增强了对不同土壤-植物系统中 ARGs 分布模式的理解，并为制定措施以最小化 ARGs 的传播提供了有效的依据。
