Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, RA Leiden, the Netherlands.
Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790, Helsinki, Finland.
Environ Pollut. 2023 Oct 15;335:122243. doi: 10.1016/j.envpol.2023.122243. Epub 2023 Jul 21.
Only recently there has been a strong focus on the impacts of microplastics on terrestrial crop plants. This study aims to examine and compare the effects of microplastics on two monocotyledonous (barley, Hordeum vulgare and wheat, Triticum aestivum), and two dicotyledonous (carrot, Daucus carota and lettuce, Lactuca sativa) plant species through two complimentary experiments. First, we investigated the effects of low, medium, and high (10, 10, 10 particles per mL) concentrations of 500 nm polystyrene microplastics (PS-MPs) on seed germination and early development. We found species-dependent effects on the early development, with microplastics only significantly affecting lettuce and carrot. When acutely exposed during germination, PS-MPs significantly delayed the germination of lettuce by 24%, as well as promoted the shoot growth of carrot by 71% and decreased its biomass by 26%. No effect was recorded on monocot species. Secondly, we performed a chronic (21 d) hydroponic experiment on lettuce and wheat. We observed that PS-MPs significantly reduced the shoot growth of lettuce by up to 35% and increased its biomass by up to 64%, while no record was reported on wheat. In addition, stress level indicators and defence mechanisms were significantly up-regulated in both lettuce and wheat seedlings. Overall, this study shows that PS-MPs affect plant development: impacts were recorded on both germination and growth for dicots, and responses identified by biochemical markers of stress were increased in both lettuce and wheat. This highlights species-dependent effects as the four crops were grown under identical conditions to allow direct comparison. For future research, our study emphasizes the need to focus on crop specific effects, while also working towards knowledge of plastic-induced impacts at environmentally relevant conditions.
直到最近，人们才开始强烈关注微塑料对陆生作物的影响。本研究旨在通过两项互补实验，研究和比较微塑料对两种单子叶植物（大麦，Hordeum vulgare 和小麦，Triticum aestivum）和两种双子叶植物（胡萝卜，Daucus carota 和生菜，Lactuca sativa）的影响。首先，我们研究了低、中、高（10、10、10 个/毫升）浓度的 500nm 聚苯乙烯微塑料（PS-MPs）对种子萌发和早期发育的影响。我们发现，微塑料对早期发育的影响具有种间依赖性，仅对生菜和胡萝卜有显著影响。在萌发过程中急性暴露时，PS-MPs 显著延迟生菜发芽 24%，同时促进胡萝卜芽生长 71%，降低其生物量 26%。对单子叶植物没有影响。其次，我们对生菜和小麦进行了为期 21 天的慢性（21 天）水培实验。我们观察到 PS-MPs 显著降低生菜的地上生长，最大可达 35%，同时增加其生物量，最大可达 64%，而对小麦没有影响。此外，生菜和小麦幼苗中的应激水平指标和防御机制显著上调。总体而言，本研究表明 PS-MPs 影响植物发育：对双子叶植物的萌发和生长均有影响，生化应激标志物鉴定出的响应在生菜和小麦中均增加。这突显了种间依赖性的影响，因为四种作物在相同条件下生长，以便进行直接比较。对于未来的研究，我们的研究强调需要关注作物特异性影响，同时努力了解在环境相关条件下塑料诱导的影响。
