State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
Environ Pollut. 2023 Apr 1;322:121199. doi: 10.1016/j.envpol.2023.121199. Epub 2023 Feb 2.
Freshwater ecosystems are gradually becoming sinks for terrestrial microplastics (MPs), posing a potential ecological risk. Although the effects of MPs on plankton and aquatic animals in freshwater ecosystems have been given increasing attention, the toxicity of MPs to the metabolism of aquatic plants remains unclear. Here, the model aquatic plant Spirodela polyrhiza (L.) Schleid. (S. polyrhiza) was exposed to polyvinyl chloride (PVC; 0, 10, 100 and 1000 mg/L) MPs, and changes in the plant functional traits and physiological metabolism were monitored. The results showed that the high dose of PVC MPs decreased the adventitious root elongation ratio by 41.68% and leaf multiplication ratio by 61.03% of S. polyrhiza, and resulted in the decrease in anthocyanin and nitrogen contents to 63.45% and 84.21% of the control group, respectively. Moreover, the widely targeted metabolomics analysis results showed 37 differential metabolites in the low-dose treatment and 119 differential metabolites in the high-dose treatment. PVC MPs interfered with organic matter accumulation by affecting carbon metabolism, nitrogen metabolism, amino acid metabolism and lipid metabolism, and S. polyrhiza resists PVC MP stress by regulating the synthesis and metabolism of secondary metabolites. PVC MPs had concentration-related toxicological effects on plant functional traits, inhibited plant growth and reproduction, affected plant nutrient metabolism, and exhibited profound effects on the nitrogen fate of aquatic plant habitats. Overall, we systematically summarized the metabolic response mechanisms of aquatic plants to PVC MP stress, providing a new perspective for studying the effects of MPs on plant trait function and ecological risks.
淡水生态系统逐渐成为陆地微塑料（MPs）的汇，构成潜在的生态风险。尽管 MPs 对淡水生态系统中浮游生物和水生动物的影响受到越来越多的关注，但 MPs 对水生植物代谢的毒性仍不清楚。在此，选用模式水生植物浮萍（Spirodela polyrhiza（L.）Schleid.）暴露于聚氯乙烯（PVC；0、10、100 和 1000 mg/L） MPs 中，监测植物功能性状和生理代谢的变化。结果表明，高剂量的 PVC MPs 使浮萍的不定根伸长率降低了 41.68%，叶繁殖率降低了 61.03%，导致花青素和氮含量分别降低至对照组的 63.45%和 84.21%。此外，广泛靶向代谢组学分析结果显示，低剂量处理有 37 个差异代谢物，高剂量处理有 119 个差异代谢物。PVC MPs 通过影响碳代谢、氮代谢、氨基酸代谢和脂质代谢来干扰有机物的积累，浮萍通过调节次生代谢物的合成和代谢来抵抗 PVC MP 胁迫。PVC MPs 对植物功能性状具有浓度相关的毒性作用，抑制植物生长和繁殖，影响植物营养代谢，对水生植物生境的氮命运产生深远影响。总的来说，我们系统地总结了水生植物对 PVC MP 胁迫的代谢响应机制，为研究 MPs 对植物性状功能和生态风险的影响提供了新的视角。
