Khan Muhammad Amjad, Kumar Sunjeet, Wang Qingqing, Wang Mengzhao, Fahad Shah, Nizamani Mir Muhammad, Chang Kenlin, Khan Sardar, Huang Qing, Zhu Guopeng
Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province/Center for Eco-Environmental Restoration Engineering of Hainan Province/College of Ecology & Environment/State Key Laboratory of Marine Resource Utilization in South China Sea/Key Laboratory for Environmental Toxicology of Haikou/Key Laboratory of Advanced Materials of Tropical Island Resources/Key Laboratory for Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, Hainan, 570228, China; Department of Environmental Sciences, University of Peshawar, Khyber Pakhtunkhwa, Peshawar 25120, Pakistan.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Horticulture, Hainan University, Haikou 570228, China.
Ecotoxicol Environ Saf. 2023 Feb;251:114526. doi: 10.1016/j.ecoenv.2023.114526. Epub 2023 Jan 11.
The extensive use of plastic products and rapid industrialization have created a universal concern about microplastics (MPs). MPs can pose serious environmental risks when combined with heavy metals. However, current research on the combined effects of MPs and hexavalent chromium [Cr(VI)] on plants is insufficient. Herein, a 14-day hydroponic experiment was conducted to investigate the impact of PVC MPs (100 and 200 mg/L) and Cr(VI) (5, 10, and 20 μM) alone and in combination on sweet potato. Results showed that combined Cr(VI) and PVC MPs affected plant growth parameters significantly, but PVC MPs alone did not. The combined application of PVC MPs and Cr(VI) resulted in a decrease in plant height (24-65%), fresh biomass per plant (36-71%), and chlorophyll content (16-34%). Cr(VI) bioaccumulation increased with the increase in its doses, with the highest concentration of Cr(VI) in the leaves (16.45 mg/kg), stems (13.81 mg/kg), and roots (236.65 mg/kg). Cr(VI) and PVC MPs-induced inhibition varied with Cr(VI) and PVC MPs doses. Osmolytes and antioxidants, lipid peroxidation, and HO contents were significantly increased, while antioxidant enzymes except CAT were decreased with increasing Cr(VI) concentration alone and mixed treatments. The presence of PVC MPs promoted Cr(VI) accumulation in sweet potato plants, which clearly showed severe toxic effects on their physio-biochemical characteristics, as indicated by a negative correlation between Cr(VI) concentration and these parameters. PVC MPs alone did not significantly inhibit these parameters. The findings of this study provide valuable implications for the proper management of PVC MPs and Cr(VI) in sweet potato plants.
塑料制品的广泛使用和快速工业化引发了人们对微塑料（MPs）的普遍关注。微塑料与重金属结合时会带来严重的环境风险。然而，目前关于微塑料和六价铬[Cr(VI)]对植物联合效应的研究尚不充分。在此，进行了一项为期14天的水培实验，以研究聚氯乙烯微塑料（100和200毫克/升）和Cr(VI)（5、10和20微摩尔）单独及联合作用对甘薯的影响。结果表明，Cr(VI)和聚氯乙烯微塑料联合显著影响植物生长参数，但单独的聚氯乙烯微塑料则没有。聚氯乙烯微塑料和Cr(VI)联合施用导致株高降低（24 - 65%）、单株鲜生物量降低（36 - 71%）以及叶绿素含量降低（16 - 34%）。Cr(VI)的生物累积量随其剂量增加而增加，叶片中Cr(VI)的最高浓度为16.45毫克/千克，茎中为13.81毫克/千克，根中为236.65毫克/千克。Cr(VI)和聚氯乙烯微塑料诱导的抑制作用随Cr(VI)和聚氯乙烯微塑料剂量而变化。单独的Cr(VI)浓度增加以及混合处理时，渗透调节物质和抗氧化剂、脂质过氧化和过氧化氢含量显著增加，而除过氧化氢酶外的抗氧化酶减少。聚氯乙烯微塑料的存在促进了Cr(VI)在甘薯植株中的积累，这对其生理生化特性产生了明显的严重毒性影响，Cr(VI)浓度与这些参数之间呈负相关表明了这一点。单独的聚氯乙烯微塑料对这些参数没有显著抑制作用。本研究结果为甘薯植株中聚氯乙烯微塑料和Cr(VI)的合理管理提供了有价值的启示。
