College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, People's Republic of China.
Sci Total Environ. 2023 Jul 15;882:163560. doi: 10.1016/j.scitotenv.2023.163560. Epub 2023 Apr 18.
Nanoplastics are an emerging environmental pollutant, having a potential risk to the terrestrial ecosystem. In the natural environment, almost all the micro-or nano-plastics will be aged by many factors and their characterizations of the surface will be modified. However, the toxicity and mechanism of the modified polystyrene nanoparticles (PS-NPs) to plant cells are not clear. In the study, the amino- and carboxyl-modified PS-NPs with different sizes (20 and 200 nm) were selected as the typical representatives to investigate their effects on protoplast cell viability, reactive oxygen species (ROS) production in the cell and the leakage of cell-inclusion and apoptosis. The results indicated that the 20 nm amino-modified PS-NPs (PS-20A) could significantly damage the structure of the cell, especially the cell membrane, chloroplast and mitochondrion. After being modified by amino group, smaller size nanoplastics had the potential to cause more severe damage. In addition, compared with carboxyl-modified PS-NPs, the amino-modified PS-NPs induced more ROS production and caused higher membrane permeability/lactate dehydrogenase (LDH) leakage. Apoptosis assay indicated that the proportion of viable cells in the PS-20A treatment decreased significantly, and the proportion of necrotic cells increased by four times. This study provides new insights into the toxicity and damage mechanism of PS-NPs to terrestrial vascular plants at the cellular level, and guides people to pay attention to the quality and safety of agricultural products caused by nanoplastics.
纳米塑料是一种新兴的环境污染物，对陆地生态系统具有潜在风险。在自然环境中，几乎所有的微纳米塑料都会受到多种因素的影响而老化，其表面特性也会发生改变。然而，改性聚苯乙烯纳米颗粒（PS-NPs）对植物细胞的毒性和作用机制尚不清楚。在本研究中，选择不同粒径（20 和 200nm）的氨基和羧基改性 PS-NPs 作为典型代表，研究它们对原生质体细胞活力、细胞内活性氧（ROS）产生和细胞内包涵物渗漏以及细胞凋亡的影响。结果表明，20nm 氨基改性 PS-NPs（PS-20A）能显著破坏细胞结构，尤其是细胞膜、叶绿体和线粒体。经过氨基改性后，较小粒径的纳米塑料具有造成更严重损伤的潜力。此外，与羧基改性 PS-NPs 相比，氨基改性 PS-NPs 诱导产生更多的 ROS，导致更高的膜通透性/乳酸脱氢酶（LDH）渗漏。凋亡分析表明，PS-20A 处理组中活细胞的比例明显下降，坏死细胞的比例增加了四倍。本研究为 PS-NPs 对陆地维管束植物在细胞水平上的毒性和损伤机制提供了新的见解，指导人们关注纳米塑料对农产品质量和安全的影响。
