Investigating the Ecotoxicity of DEHP and ZnO NPs in Dandelion: Effects on Growth, Physiology, and Metabolite Profiles

Abstract

Di(2-ethylhexyl)phthalate (DEHP) and ZnO nanoparticles (NPs) pose significant environmental threats that can negatively influence plant growth and health. This study thoroughly investigated the effects of both single and combined exposures to DEHP and ZnO NPs on dandelion (Taraxacum officinale F.H.Wigg) seedlings. The results demonstrated that both DEHP and ZnO significantly reduced in biomass (58.34% in shoots, 42.01% in roots). These treatments also led to a marked decline in chlorophyll fluorescence and exacerbated oxidative stress. Notably, the presence of ZnO NPs intensified DEHP toxicity by increasing its accumulation in roots (by 25.73%) while restricting its translocation to shoots, thereby amplifying its environmental risk. Additionally, dandelion responses exhibited tissue specificity, with roots being more adversely affected than shoots. Metabolomic analysis revealed substantial alterations in metabolites abundance and key metabolic pathways, including those involved in amino acid biosynthesis, carbohydrate metabolism, and fatty acid metabolism. Furthermore, ZnO NPs significantly modified the profiles of secondary metabolites in dandelions subjected to DEHP stress, specifically flavonoids and phenolic acids, which may influence the plant’s medicinal properties. These findings underscore the complexity of the plant defense mechanisms against environmental pollutants. This study provides valuable insights into the toxicological interactions between DEHP and ZnO NPs, emphasizing the need for further research on their long-term effects across diverse plant species.