Table_Significant_Genera_AntibioticProcesses.xlsx

Antibiotic contamination from biogenic waste in agricultural soils poses a significant threat to soil health and crop productivity. We investigated the effect of antibiotics on the soil microbial community, antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) and plant productivity in a six week greenhouse trial. Here, Spinacia oleracea (spinach) and Raphanus sativus (radish) were grown from seed and a mix of five antibiotics, namely sulfamethoxazole, trimethoprim, enrofloxacin, clarithromycin and chlortetracycline, were added to the soil at concentrations 0, 0.1, 1 and 10 mg kg-1 soil dry weight (c0, c0.1, c1 and c10, respectively). Overall we found that the antibiotic treatments significantly impacted prokaryotic α-diversity and prokaryotic and fungal β-diversity. Human and plant pathogen abundance did not increase under antibiotic exposure, but there was a significant reduction of plant growth-promoting bacteria. Moreover, the c10 treatment significantly increased the abundance of MGE intI1 indicative of horizontal gene transfer and ARG sul1 sulfamethoxazole antibiotic resistance and significantly lowered radish biomass and nitrogen uptake, while spinach biomass and nitrogen uptake was unaffected. In summary, our study showed that antibiotic exposure significantly changed prokaryotic community diversity and taxonomy, while fungi remained largely unaffected. The reduction of plant growth-promoting bacteria may have a significant impact on soil nutrient cycling and crop productivity, but more research is needed to understand the long-term impact of these co-applied antibiotics on food production. Additionally, more studies are needed to understand the effect of antibiotics in realistic, field scale, conditions to fully understand the impact on environmental and human health.

农业土壤中生物源废弃物引发的抗生素污染，对土壤健康与作物生产力构成严重威胁。本研究依托为期六周的温室盆栽试验，探究了抗生素对土壤微生物群落、抗生素抗性基因（antibiotic resistance genes, ARGs）、可移动遗传元件（mobile genetic elements, MGEs）以及作物生产力的影响。试验以菠菜（Spinacia oleracea）与萝卜（Raphanus sativus）为供试作物，由种子播种培育，同时向土壤中施加由五种抗生素组成的混合药剂，分别为磺胺甲恶唑、甲氧苄啶、恩诺沙星、克拉霉素与金霉素，设置的浓度梯度为0、0.1、1、10 mg·kg⁻¹ 干土，各组依次记为c0、c0.1、c1与c10。

整体而言，抗生素处理显著影响了原核生物的α多样性，以及原核生物与真菌的β多样性。抗生素暴露条件下，人类与植物病原菌的丰度未出现上升，但植物促生细菌的丰度显著降低。此外，c10处理组显著提升了可指示水平基因转移的可移动遗传元件intI1以及针对磺胺甲恶唑的抗生素抗性基因sul1的丰度，同时显著降低了萝卜的生物量与氮吸收量，但对菠菜的生物量及氮吸收量无显著影响。

综上，本研究发现抗生素暴露显著改变了原核生物群落的多样性与分类组成，而真菌群落基本未受影响。植物促生细菌的丰度降低可能对土壤养分循环与作物生产力产生显著影响，但仍需开展更多研究以明确这类复合施用的抗生素对粮食生产的长期影响。此外，还需开展更多基于真实田间规模条件的研究，以全面阐明抗生素对环境与人类健康的影响。