摘要

  越来越多的证据表明，在农业中用作有机肥料的牲畜粪便可能会导致抗生素抗性基因 (ARG) 从“农场到餐桌”的潜在传播。然而，关于肥料施肥对植物相关微生物群落（包括根际、内圈和叶际）中 ARG 发生率的影响知之甚少，这阻碍了我们评估土壤-植物系统中抗生素抗性传播的能力。在这里，我们构建了一个盆栽实验，以探索家禽和牛粪施用对收获的樱桃萝卜植物微生物群中抗性组变化的影响。在所有样品中共检测到 144 个 ARG，它们对八类主要抗生素具有抗性。与樱桃萝卜的根内生微生物组相比，根际和叶际微生物组具有显着更高的 ARG 多样性和丰度。施肥显着增加了根际和叶际中 ARGs 的丰度，但在根的内生菌中没有增加，根的内生菌是樱桃萝卜的可食用部分。施肥后土壤和植物微生物组发生了巨大变化，并根据不同的样品类型和处理方式分别聚集。结构方程模型表明，在考虑了多种驱动因素后，细菌丰度是调节土壤和植物抵抗组分布模式的最重要因素。总之，我们提供的证据表明，施肥后樱桃萝卜根际和叶际中抗性组的富集比内生更明显，表明在盆栽实验中，粪肥改良剂可能不会增强 ARGs 向蔬菜根部的传播.

  Growing evidence suggests that livestock manure used as organic fertilizer in agriculture may lead to the potential propagation of antibiotic resistance genes (ARGs) from “farm to fork.” However, little is known about the impacts of manure fertilization on the incidence of ARGs in the plant-associated microbiomes (including rhizosphere, endosphere, and phyllosphere), which hampers our ability to assess the dissemination of antibiotic resistance in the soil-plant system. Here, we constructed a pot experiment to explore the effects of poultry and cattle manure applications on the shifts in the resistome in the plant microbiome of harvested cherry radish. A total of 144 ARGs conferring resistance to eight major classes of antibiotics were detected among all the samples. Rhizosphere and phyllosphere microbiomes harbored significantly higher diversity and abundance of ARGs than did root endophytic microbiomes of cherry radish. Manure application significantly increased the abundance of ARGs in the rhizosphere and phyllosphere but not in the endophytes of the root, which is the edible part of cherry radish. Soil and plant microbiomes changed dramatically after manure applications and clustered separately according to different sample types and treatments. Structural equation modeling revealed that bacterial abundance was the most important factor modulating the distribution patterns of soil and plant resistomes after accounting for multiple drivers. Taken together, we provide evidence that enrichment of the resistome in the rhizosphere and phyllosphere of cherry radish is more obvious than with the endosphere after manure application, suggesting that manure amendment might not enhance the dissemination of ARGs into the root of vegetables in the pot experiment.

  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6952223/