Key Laboratory of Groundwater Resources and Environment of the Ministry of Education (Jilin University), China; Jilin Provincial Key Laboratory of Water Resources and Environment, China; College of New Energy and Environment, Jilin University, Changchun, 130012, China.
Key Laboratory of Groundwater Resources and Environment of the Ministry of Education (Jilin University), China; Jilin Provincial Key Laboratory of Water Resources and Environment, China; College of New Energy and Environment, Jilin University, Changchun, 130012, China.
Plant Physiol Biochem. 2024 Jun;211:108716. doi: 10.1016/j.plaphy.2024.108716. Epub 2024 May 9.
In the context of global climate change, recurrent freeze-thaw cycles (FTC) and concurrent exposure to polystyrene nanoplastics (PSNPs) directly impact crop growth and indirectly affect resilience to abiotic stress. In January 2023, experiments at the Environmental Biology Laboratory, Jilin University, Changchun, China, exposed rye seedlings to 100 nm PSNPs at concentrations of 0, 10, 50, and 100 mg/L for seven days, followed by three FTC. Scanning electron microscopy (SEM) demonstrated that PSNPs migrated from the roots to the leaves, with FTC significantly exacerbating their accumulation within plant tissues. Transmission electron microscopy (TEM) observations showed that FTC disrupted normal cell division, and combined stress from NPs damaged plant organs, particularly chloroplasts, thereby substantially inhibiting photosynthesis. FTC delayed plant phenological stages. Under combined stress, malondialdehyde (MDA) accumulation in plant tissues increased by 15.6%, while hydrogen peroxide (HO) content decreased. Simultaneously, the activities of peroxidase (POD) and catalase (CAT) increased by 34.2% and 38.6%, respectively. Molecular docking unveiled that PSNPs could bind to the active center of POD/CAT through hydrogen bonding or hydrophobic interactions. The Integrated Biomarker Response (IBR) index highlighted FTC as a crucial determinant for pronounced effects. Moreover, an apparent dose-dependent effect was observed, with antioxidant enzyme activities in rye seedlings induced by low pollutant concentrations and inhibited by high concentrations. These results indicate that FTC and PSNPs can disrupt plant membrane systems and cause severe oxidative damage. Overall, this study provides compelling scientific evidence of the risks associated with NPs exposure in plants subjected to abiotic stress.
在全球气候变化的背景下，反复的冻融循环（FTC）和同时暴露于聚苯乙烯纳米塑料（PSNPs）直接影响作物生长，并间接地影响对非生物胁迫的恢复力。2023 年 1 月，中国吉林大学环境生物学实验室在长春进行的实验将黑麦幼苗暴露于浓度为 0、10、50 和 100mg/L 的 100nm PSNPs 中 7 天，随后进行了三次 FTC。扫描电子显微镜（SEM）显示，PSNPs 从根部迁移到叶片，FTC 显著加剧了它们在植物组织内的积累。透射电子显微镜（TEM）观察表明，FTC 破坏了正常的细胞分裂，而 NPs 造成的联合胁迫损害了植物器官，特别是叶绿体，从而极大地抑制了光合作用。FTC 延迟了植物物候阶段。在联合胁迫下，植物组织中丙二醛（MDA）的积累增加了 15.6%，而过氧化氢（HO）含量下降。同时，过氧化物酶（POD）和过氧化氢酶（CAT）的活性分别增加了 34.2%和 38.6%。分子对接表明，PSNPs 可以通过氢键或疏水相互作用与 POD/CAT 的活性中心结合。综合生物标志物响应（IBR）指数强调 FTC 是产生显著影响的关键决定因素。此外，观察到明显的剂量依赖效应，低浓度污染物诱导黑麦幼苗中抗氧化酶活性增加，而高浓度则抑制。这些结果表明，FTC 和 PSNPs 可以破坏植物的膜系统，并导致严重的氧化损伤。总的来说，这项研究提供了确凿的科学证据，表明 NPs 暴露在遭受非生物胁迫的植物中存在风险。
