State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Plant Physiol Biochem. 2024 Nov;216:109155. doi: 10.1016/j.plaphy.2024.109155. Epub 2024 Sep 25.
Microplastics (MPs) are important carriers of various toxic metals and can alter their toxicity pattern in agricultural soil, leading to combined pollution, therefore posing new challenges to soil pollution management and environmental risk assessment. In this study, we observed the internalization of MPs in plants and conducted incubation experiments to evaluated the effects of arsenate (As(V)) alone and in combination with polystyrene (PS) MPs on wheat seedlings (Triticum aestivum L.). Under As(V) alone and combined with PS-MP exposure, dose-dependent toxicity in terms of root and stem elongation and biomass accumulation was observed. Compared with As(V) alone, the presence of PS-MPs reduced the accumulation of As in wheat roots by 11.43-58.91%, but PS-MPs intensified the transport of As to the aboveground parts of wheat, increasing As accumulation in wheat stems by 27.77-1011.54%. This causes more serious mechanical damage and oxidative stress to plant cells, increasing the accumulation of reactive oxygen species and lipid peroxidation in wheat roots and upregulating the activities of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). In addition, the co-exposure of As(V) and PS-MPs disrupts the photosynthetic system of wheat leaves and the secretion activities of roots. Therefore, the combination of As(V) and PS-MPs caused greater damage to wheat growth. Our findings contribute to a more comprehensive assessment of the combined toxicity of MPs and heavy metal to crops.
微塑料(MPs)是各种有毒金属的重要载体,它们可以改变有毒金属在农业土壤中的毒性模式,导致复合污染,从而对土壤污染管理和环境风险评估提出新的挑战。在本研究中,我们观察了 MPs 在植物体内的内化,并进行了孵育实验,以评估砷酸盐(As(V))单独和与聚苯乙烯(PS) MPs 共同暴露对小麦幼苗(Triticum aestivum L.)的影响。在 As(V)单独和与 PS-MP 共同暴露下,观察到根和茎伸长以及生物量积累的剂量依赖性毒性。与 As(V)单独暴露相比,PS-MPs 的存在降低了小麦根中 As 的积累,降低幅度为 11.43-58.91%,但 PS-MPs 加剧了 As 向小麦地上部分的转运,使小麦茎中 As 的积累增加了 27.77-1011.54%。这对植物细胞造成了更严重的机械损伤和氧化应激,增加了小麦根中活性氧和脂质过氧化产物的积累,并上调了超氧化物歧化酶(SOD)和过氧化物酶(POD)等抗氧化酶的活性。此外,As(V)和 PS-MPs 的共同暴露破坏了小麦叶片的光合作用系统和根系的分泌活动。因此,As(V)和 PS-MPs 的共同暴露对小麦生长造成了更大的损害。我们的研究结果有助于更全面地评估 MPs 和重金属对作物的复合毒性。