With increasing plastic production and consumption, large amounts of polystyrene nanoplastics are accumulated in soil due to improper disposal causing pollution and deleterious effects to environment. However, little information is available about how to alleviate the adverse impacts of nanoplastics on crops. In this study, the involvement of melatonin in modulating nanoplastic uptake, translocation, and toxicity in wheat plant was investigated. The results demonstrated that exogenous melatonin application reduced the nanoplastic uptake by roots and their translocation to shoots via regulating the expression of genes associated with aquaporin, including the upregulation of the TIP2-9, PIP2, PIP3, and PIP1.2 in leaves and TIP2-9, PIP1-5, PIP2, and PIP1.2 in roots. Melatonin activated the ROS scavenging system to maintain a better redox homeostasis and ameliorated the negative effects of nanoplastics on carbohydrate metabolism, hence ameliorated the plant growth and enhanced the tolerance to nanoplastics toxicity. This process was closely related to the exogenous melatonin application induced melatonin accumulation in leave. These results suggest that melatonin could alleviate the adverse effects of nanoplastics on wheat, and exogenous melatonin application might be used as a promising management strategy to sustain crop production in the nanoplastic-polluted soils.

中文翻译：

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褪黑激素可降低小麦对纳米塑料的吸收、转运和毒性

随着塑料生产和消费量的增加，大量聚苯乙烯纳米塑料由于处理不当而堆积在土壤中，对环境造成污染和有害影响。然而，关于如何减轻纳米塑料对农作物的不利影响的信息很少。在这项研究中，研究了褪黑激素在调节小麦植物中纳米塑料吸收、易位和毒性中的作用。结果表明，外源褪黑激素的应用通过调节与水通道蛋白相关的基因的表达，包括TIP2-9、PIP2、PIP3和PIP1.2的上调，减少了根系对纳米塑料的吸收及其向芽的转移。在叶子中和在根中的TIP2-9、PIP1-5、PIP2和PIP1.2。褪黑激素激活 ROS 清除系统以维持更好的氧化还原稳态并改善纳米塑料对碳水化合物代谢的负面影响，从而改善植物生长并增强对纳米塑料毒性的耐受性。这一过程与外源褪黑素应用诱导的褪黑素在叶片中积累密切相关。这些结果表明，褪黑激素可以减轻纳米塑料对小麦的不利影响，外源褪黑激素的应用可作为一种有前景的管理策略，以维持纳米塑料污染土壤中的作物生产。