Department of Biology, Università degli Studi di Firenze, via Micheli 1, 50121 Florence, Italy.
Department of Biology, Università degli Studi di Firenze, via Micheli 1, 50121 Florence, Italy; Department of Agriculture, Università degli Studi di Firenze, Viale delle Idee 30, Sesto Fiorentino, 50019 Florence, Italy.
J Hazard Mater. 2022 Feb 5;423(Pt B):127238. doi: 10.1016/j.jhazmat.2021.127238. Epub 2021 Sep 16.
In this study, Cucurbita pepo L., one of the most cultivated, consumed and economically important crop worldwide, was used as model plant to test the toxic effects of the four most abundant microplastics identified in contaminated soils, i.e. polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), and polyethyleneterephthalate (PET). Cucurbita plants were grown in pots with increasing concentrations of the microplastics, then plant biometry, photosynthetic parameters and ionome of treated vs. untreated samples were compared to evaluate the toxicity of each plastic. All the pollutants impaired root and, especially, shoot growth. Specific and concentration-dependant effects of the different microplastics were found, including reduction in leaf size, chlorophyll content and photosynthetic efficiency, as well as changes in the micro- and macro-elemental profile. Among all the microplastics, PVC was identified as the most toxic and PE as the less toxic material. PVC decreased the dimensions of the leaf lamina, the values of the photosynthetic performance index and the plant iron concentration to a higher extent in respect to the other treatments. Microplastic toxicity exerted on the growth of C. pepo raises concerns about possible yield and economic loss, as well as for risks of a possible transfer into the food chain.
在这项研究中，我们选择了南瓜（Cucurbita pepo L.）作为模式植物，这种植物是全球种植最广泛、消费最多、经济价值最高的作物之一，用于测试在受污染土壤中发现的四种最丰富的微塑料（即聚丙烯（PP）、聚乙烯（PE）、聚氯乙烯（PVC）和聚对苯二甲酸乙二醇酯（PET））的毒性效应。我们将南瓜种植在盛有不同浓度微塑料的花盆中，然后比较处理和未处理样品的植物生物计量学、光合作用参数和离子组，以评估每种塑料的毒性。所有污染物都损害了根，尤其是地上部分的生长。发现不同微塑料具有特定且浓度依赖的效应，包括叶片大小、叶绿素含量和光合作用效率的降低，以及微元素和宏量元素谱的变化。在所有微塑料中，PVC 被确定为最具毒性的材料，PE 则是毒性较小的材料。与其他处理相比，PVC 降低了叶片的面积、光合作用性能指数的值以及植物铁浓度。微塑料对南瓜生长的毒性引起了人们对可能的产量和经济损失的担忧，以及对可能进入食物链的风险的担忧。
