摘要
      牲畜粪便经常被用作温室中的肥料，导致土壤中重金属和抗生素抗性基因（ARGs）同时富集。土壤-植物系统是传播ARGs的一种不可忽视的方式；然而，铅（Pb）对ARGs传播的影响及其在温室土壤-植物系统中的驱动因素尚不清楚。在本研究中，研究了铅胁迫下ARGs在温室土壤中的发生及其在植物中的扩散。总的来说，Pb在10、50和100 mg/kg时促进了ARGs在根内生菌中的积累，在10和200 mg/kg时也促进了土壤中ARGs的积累，但降低了叶内生菌的ARGs总相对丰度。特别是，Pb增加了根系中的移动遗传元素（MGEs）相对丰度和内生细菌群落多样性，与ARGs总相对丰度的变化一致。网络分析表明，细菌群落和MGE可能共同影响ARGs在温室土壤-植物系统中的迁移。总的来说，这项研究扩展了我们对铅如何促进ARGs从接受长期施肥的温室土壤传播到植物根部的知识，在评估ARGs对公众健康的风险时必须考虑这一点。
Abstract
Livestock manure is often used as fertilizer in greenhouses, resulting in simultaneous enrichment of heavy metals and antibiotic resistance genes (ARGs) in soils. The soil-plant system is a non-negligible way to spread ARGs; however, the effects of lead (Pb) on the spread of ARGs and their driving factors in the greenhouse soil-plant system remain unclear. In this present study, the occurrence of ARGs in greenhouse soils and their spread into plants under Pb stress were studied. Overall, Pb promoted the accumulation of ARGs in root endophytes at 10, 50, and 100 mg/kg as well as in soils at 10 and 200 mg/kg, but reduced the total relative abundance of ARGs in leaf endophytes. Particularly, Pb increased the mobile genetic elements (MGEs) relative abundance and endophytic bacterial community diversity in roots, consistent with the change in the total relative abundance of ARGs. Network analysis revealed that bacterial community and MGEs may jointly affect the migration of ARGs in the soil-plant system of greenhouses. Overall, this study extended our knowledge of how Pb can promote the transmission of ARGs to plant roots from greenhouse soils receiving long-term manure applications, which must be considered when assessing the risk of ARGs to public health.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722058557