Data Sheet 1_Migration pattern and biochemical response characteristics of polylactic acid nanoparticles in pakchoi (Brassica chinensis L. cv. SuZhou) seedlings.pdf

Nanoplastics represent an emerging class of pollutants that infiltrate aquatic and terrestrial environments through diverse pathways, posing significant threats to ecosystems. However, research on the accumulation and translocation mechanisms of biodegradable nanoplastics in plants remains limited. In this investigation, pakchoi (Brassica chinensis L. cv. SuZhou) was exposed to fluorescently labeled polylactic acid nanoplastics (PLA-NPs) in hydroponic solutions with varying concentrations (20 mg/L, 50 mg/L) and particle sizes (170 nm, 330 nm) to investigate the migration, distribution patterns, and associated toxicological responses of PLA-NPs in pakchoi. Both microscopic imaging and fluorescence semi-quantitative analysis confirmed that PLA-NPs of both tested particle sizes can enter the root system via the apical meristem and primary root-lateral root junction. Furthermore, PLA-NPs with a smaller particle size (170 nm) and higher concentration (50 mg/L) are more readily absorbed and accumulated by roots, and subsequently translocated to aboveground tissues. When roots were exposed to PLA-NPs, the activities of superoxide dismutase, peroxidase, and catalase in pakchoi significantly decreased, while hydrogen peroxide and malondialdehyde levels increased. Concurrently, soluble sugar, soluble protein, and chlorophyll content also changed. Moreover, the magnitude of these changes increased with the increase in PLA-NPs particle size and concentration. Collectively, PLA-NPs accumulate in pakchoi seedling roots, translocate to aboveground tissues, and potentially posing certain risks to human health through the food chain.

纳米塑料是一类新兴污染物，可通过多种途径侵入水生与陆生环境，对生态系统构成显著威胁。然而，针对可生物降解纳米塑料在植物体内的积累与转运机制的研究仍较为有限。本研究以苏州青小白菜（Brassica chinensis L. cv. SuZhou）为受试材料，在浓度分别为20 mg/L、50 mg/L，粒径分别为170 nm、330 nm的水培体系中暴露于荧光标记聚乳酸纳米塑料（PLA-NPs），以探究PLA-NPs在小白菜体内的迁移、分布模式及相关毒理响应。显微成像与荧光半定量分析均证实，两种测试粒径的PLA-NPs均可通过顶端分生组织与主根-侧根连接点进入根系。进一步研究发现，粒径更小（170 nm）、浓度更高（50 mg/L）的PLA-NPs更易被根系吸收积累，并随后转运至地上组织。当根系暴露于PLA-NPs时，小白菜体内超氧化物歧化酶、过氧化物酶及过氧化氢酶活性显著降低，而过氧化氢与丙二醛含量升高；与此同时，可溶性糖、可溶性蛋白及叶绿素含量亦发生改变。此外，这些变化的幅度随PLA-NPs粒径与浓度的升高而增大。综上，PLA-NPs可在小白菜幼苗根系中积累，并转运至地上组织，且可能通过食物链对人体健康构成潜在风险。