Abstract：
A significant knowledge gap exists regarding the impact of soil organic matter on the bioavailability of Ag2S-NPs (environmentally relevant forms of Ag-NPs) in soil-earthworm-plant systems. This study used two soils with varying organic matter content, both with and without earthworms, to investigate the bioavailability of Ag2S-NPs. The findings revealed an 80 % increase in Ag bioaccessibility to soybeans in soils with high organic matter content compared to soils with low organic matter. Additionally, the presence of earthworms significantly increased Cl concentrations from 24.3-62.2 mg L-1 to 80.1-147.2 mg L-1, triggering the elevated bioavailability of Ag. Interestingly, Ag2S-NPs eliminated the stimulative effects of earthworms on plant nutrient uptake. In the presence of earthworms, the high organic matter soil amended with Ag2S-NPs exhibited lower concentrations of essential elements (Ca, Cu, Fe, K, and P) in plant tissues compared to soils without earthworms. Our study presents evidence of the transformation of Ag2S-NPs into Ag-NPs across various soil solutions, resulting in the formation of Ag nanoparticle complexes. Particularly noteworthy is the significant reduction in particle sizes in soils incubated with earthworms and high organic matter content, from 85.0 nm to 40.2 nm. Notably, in the rhizosphere soil, a decrease in the relative abundance of nutrient cycling-related phyla was observed, with reductions of 18.5 % for Proteobacteria and 30.0 % for Actinobacteriota. These findings offer valuable insights into the biological and biochemical consequences of Ag2S-NP exposure on earthworm-mediated plant nutrient acquisition.
摘要：
关于土壤有机质对土壤-蚯蚓-植物系统中Ag2S-NP（与环境相关的Ag-NP形式）的生物利用度的影响，存在着巨大的知识差距。这项研究使用了两种有机质含量不同的土壤，有和没有蚯蚓，研究Ag2S-NP的生物利用度。研究结果表明，与有机质含量低的土壤相比，有机质含量高的土壤中Ag对大豆的生物可得性增加了80％。此外,蚯蚓的存在使Cl浓度从24.3-62.2mgL-1显着增加到80.1-147.2mgL-1，从而引发了Ag的生物利用度提高。有趣的是,Ag2S-NP消除了蚯蚓对植物养分吸收的促进作用。在蚯蚓面前,用Ag2S-NP修正的高有机质土壤表现出较低的基本元素浓度(Ca，Cu,Fe,K,与没有蚯蚓的土壤相比，植物组织中的P）。我们的研究提供了Ag2S-NP在各种土壤溶液中转化为Ag-NP的证据，导致Ag纳米颗粒复合物的形成。特别值得注意的是,蚯蚓培养的土壤中,有机质含量高的土壤中,颗粒大小显著减少,从85.0nm到40.2nm。值得注意的是,在根际土壤中，观察到与营养循环相关的门的相对丰度下降，变形杆菌减少18.5%，放线菌减少30.0%。这些发现为Ag2S-NP暴露对蚯蚓介导的植物养分获取的生物学和生化后果提供了有价值的见解。
