MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
J Hazard Mater. 2024 Jul 5;472:134578. doi: 10.1016/j.jhazmat.2024.134578. Epub 2024 May 11.
Microplastics (MPs) are widespread in agricultural soil, potentially threatening soil environmental quality and plant growth. However, toxicological research on MPs has mainly been limited to individual components (such as plants, microbes, and animals), without considering their interactions. Here, we examined earthworm-mediated effects on tomato growth and the rhizosphere micro-environment under MPs contamination. Earthworms (Eisenia fetida) mitigated the growth-inhibiting effect of MPs on tomato plant. Particularly, when exposed to environmentally relevant concentrations (ERC, 0.02% w/w) of MPs, the addition of earthworms significantly (p < 0.05) increased shoot and root dry weight by 12-13% and 13-14%, respectively. MPs significantly reduced (p < 0.05) soil ammonium (NH-N) (0.55-0.69 mg/kg) nitrate nitrogen (NO-N) (7.02-8.65 mg/kg) contents, and N cycle related enzyme activities (33.47-42.39 μg/h/g) by 37.7-50.9%, 22.6-37.2%, and 34.2-48.0%, respectively, while earthworms significantly enhanced (p < 0.05) inorganic N mineralization and bioavailability. Furthermore, earthworms increased bacterial network complexity, thereby enhancing the robustness of the bacterial system to resist soil MPs stress. Meanwhile, partial least squares modelling showed that earthworms significantly influenced (p < 0.01) soil nutrients, which in turn significantly affected (p < 0.01) plant growth. Therefore, the comprehensive consideration of soil ecological composition is important for assessing MPs ecological risk.
微塑料（MPs）广泛存在于农业土壤中，可能对土壤环境质量和植物生长构成威胁。然而，关于 MPs 的毒理学研究主要局限于单个成分（如植物、微生物和动物），而没有考虑它们之间的相互作用。在这里，我们研究了 MPs 污染下蚯蚓对番茄生长和根际微环境的介导作用。蚯蚓（赤子爱胜蚓）减轻了 MPs 对番茄植物生长的抑制作用。特别是，当暴露于环境相关浓度（ERC，0.02%w/w）的 MPs 时，添加蚯蚓显著（p<0.05）增加了 12-13%和 13-14%的地上部和根部干重。 MPs 显著降低（p<0.05）了土壤铵态氮（NH-N）（0.55-0.69mg/kg）和硝态氮（NO-N）（7.02-8.65mg/kg）含量，以及与 N 循环相关的酶活性（33.47-42.39μg/h/g），降幅分别为 37.7-50.9%、22.6-37.2%和 34.2-48.0%，而蚯蚓显著增强了无机 N 矿化和生物有效性。此外，蚯蚓增加了细菌网络的复杂性，从而增强了细菌系统对土壤 MPs 胁迫的鲁棒性。同时，偏最小二乘模型表明，蚯蚓显著影响（p<0.01）土壤养分，进而显著影响（p<0.01）植物生长。因此，综合考虑土壤生态组成对于评估 MPs 生态风险很重要。
