摘要
      稀土元素（REE）因其对植物生长的各种有益作用而在农业生态系统中得到广泛开发。然而，稀土元素的生态毒理学效应和环境风险评估不足。在这里，我们使用基于宏基因组的方法研究了硝酸镧和铈对土壤原核生物和病毒金属抗性基因（MRGs）以及抗生素抗性基因（ARGs）的影响。我们发现原核生物门拟杆菌门和绿弯菌门的相对丰度随着两种稀土元素化合物的增加而降低。此外，低水平的REE硝酸盐（0.05和0.1 mmol kg−1土壤）抑制病毒科Phycodanaviride、Rudiviridae、Schitoviridae，而高水平的REE-硝酸盐（0.16和0.32 mmol kg–1土壤）则抑制病毒科Herelleviridae、Iridoviridae、Podoviridae。低水平的REE硝酸盐对ARGs没有显著影响。然而，高水平的硝酸稀土元素增加了对大多数药物类别（如氨基糖苷类、艾法霉素、氟喹诺酮类、大环内酯类、利福霉素）具有耐药性的优势原核生物基因的丰度。原核生物中MRG的丰度并没有随着REE-硝酸盐化合物类型和输入速率的变化而一致。在一些处理中，仅在病毒组中部分检测到MRG，而在病毒组未检测到ARGs。我们共同证明，农业中过度使用硝酸稀土元素会增加ARGs通过原核生物而不是病毒传播的风险，尽管病毒群落发生了实质性变化。
Abstract
Rare earth elements (REE) are extensively exploited in the agricultural ecosystems due to their various beneficial roles on plant growth. However, the ecotoxicological effects and environmental risk of REE are poorly assessed. Here, we investigated the effects of lanthanum and cerium nitrate on soil prokaryote and viral metal resistance genes (MRGs) and antibiotics resistance genes (ARGs) using a metagenomic-based approach. We found that relative abundances of prokaryote phyla Bacteroidetes and Chloroflexi decreased with increasing of both REE compounds. In addition, low level REE nitrate (0.05 and 0.1 mmol kg−1 soil) inhibited the viral family Phycodanaviridae, Rudiviridae, Schitoviridae, whereas high level (0.16 and 0.32 mmol kg−1 soil) REE nitrate suppressed the viral family Herelleviridae, Iridoviridae, Podoviridae. ARGs were not significantly affected by low level of REE nitrate. However, high level of both REEs nitrate increased the abundances of dominant prokaryote genes resisting to most of the drug classes, such as aminoglycoside, elfamycin, fluoroquinolone, macrolide, rifamycin. Abundance of MRGs in prokaryote did not change consistently with REE nitrate compound type and input rate. MRGs were only partially detected in the virome in some of the treatments, while ARGs was not detected in virome. Together, we demonstrated that overuse of REE nitrate in agriculture would increase the risk of dissemination of ARGs through prokaryotes but not virus, although viral community was substantially shifted.

https://www.sciencedirect.com/science/article/abs/pii/S004896972207807X