Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
J Hazard Mater. 2022 Mar 15;426:127826. doi: 10.1016/j.jhazmat.2021.127826. Epub 2021 Nov 20.
With increasing plastic consumption, the large amount of polystyrene nanoplastics (PS-NPs) in agricultural soil may not only directly affect the plant growth, but also indirectly affect the abiotic stress tolerance in crops. In this study, the barley (Hordeum vulgare L.) was irrigated with 2 g L PS-NPs (65.776 ± 0.528 nm) solution for 7 days, then subjected to low temperature (2 ℃) for 24 h. The imaging of protoplasts indicated that polymethylmethacrylate nanoplastics could across the cell wall and accumulate in plant cells. The PS-NPs significantly decreased Rubisco activities and ATP production, hence limiting the photosynthetic carbon assimilation in barley under low temperature. The PS-NPs accumulated in cells also caused the significantly decreased activities of key enzymes involved in sucrolytic, glycolysis and starch metabolism pathways, including UDP-glucose pyrophorylase, ADP-Glucose pyrophosphorylase, phosphoglucomutase, glucose-6-phosphate dehydrogenase, phosphoglucoisomerase, fructokinase and phosphofructokinase. In addition, under low temperature, the PS-NPs presence significantly reduced the activities of superoxide dismutase, ascorbate peroxidase and catalase in chloroplasts, and significantly reduced the activities of ascorbate peroxidase and catalase in mitochondria. Thus, it is suggested that the PS-NPs accumulated in plant cells impaired the low temperature tolerance in barley mainly by the negative effects on photosynthetic carbon assimilation, carbohydrate metabolism and ROS homeostasis in sub-cellular level.
随着塑料消费量的增加，大量的聚苯乙烯纳米塑料（PS-NPs）存在于农业土壤中，不仅可能直接影响植物生长，还可能间接影响作物的非生物胁迫耐受性。在这项研究中，大麦（Hordeum vulgare L.）用 2 g/L PS-NPs（65.776±0.528nm）溶液处理 7 天，然后在 2℃下处理 24 h。原生质体的成像表明，聚甲基丙烯酸甲酯纳米塑料可以穿过细胞壁并在植物细胞中积累。PS-NPs 显著降低了 Rubisco 活性和 ATP 生成，从而限制了低温下大麦的光合作用碳同化。细胞中积累的 PS-NPs 还导致与蔗糖分解代谢、糖酵解和淀粉代谢途径相关的关键酶活性显著降低，包括 UDP-葡萄糖焦磷酸化酶、ADP-葡萄糖焦磷酸化酶、磷酸葡糖变位酶、葡萄糖-6-磷酸脱氢酶、磷酸葡糖异构酶、果糖激酶和磷酸果糖激酶。此外，在低温下，PS-NPs 的存在显著降低了叶绿体中超氧化物歧化酶、抗坏血酸过氧化物酶和过氧化氢酶的活性，以及线粒体中抗坏血酸过氧化物酶和过氧化氢酶的活性。因此，PS-NPs 在植物细胞中的积累主要通过对亚细胞水平光合作用碳同化、碳水化合物代谢和 ROS 平衡的负面影响，导致大麦对低温的耐受性降低。
