Effects of microplastics and salt single or combined stresses on growth and physiological responses of maize seedlings

作者：Xiaodong Liu, Zongshuai Wang, Guiyang Shi, Yingbo Gao, Hui Zhang, Kaichang Liu · 发表于：Physiologia Plantarum · 年份：2025 · DOI：10.1111/ppl.70106 · 被引用次数：14 · 研究领域：Microplastics and Plastic Pollution、Nanoparticles: synthesis and applications、Nanocomposite Films for Food Packaging

Abstract Plastic film (mulch film) is widely used in saline and alkaline soils because it can effectively reduce salt stress damage. However, it results in the accumulation of microplastics (MPs) in the soil, which pose a threat to crop growth and production. This study investigates the effects of 50 mg l −1 MPs and 100 mM sodium chloride (NaCl), individually or in combination, on the growth and physiological characteristics of maize ( Zea mays ) seedlings. The results demonstrated that compared to the control, MPs and NaCl single or combined stress reduced seedling biomass and water content, and the combined stress was more serious. Stress significantly reduced N and K contents in leaves, and Na content under combined stress was lower than under single NaCl stress. Compared to single stress, the combined stress further enhanced oxidative damage by increasing H 2 O 2 and MDA content, a disrupted chloroplast structure, and reduced chlorophyll content, ultimately leading to a decline in chlorophyll fluorescence parameters and photosynthetic efficiency. Single MPs or NaCl stress led to the accumulation of proline, soluble proteins, and soluble sugars, while the combined stresses further increased the content of these osmotic substances in plants. Moreover, single or combined stress increased the activity of CAT, POD, SOD and the content of AsA and GsH. Collectively, NaCl and MPs single or combined stress exert notable toxic effects on maize seedling growth. Although the combined...