Effect of polystyrene on di-butyl phthalate (DBP) bioavailability and DBP-induced phytotoxicity in lettuce. (1st January 2021)

• Record Type: Journal Article
• Authors: Gao, Minling; Xu, Yalei; Liu, Yu; Wang, Shengli; Wang, Chengwei; Dong, Youming; Song, Zhengguo
• Is Part Of: Environmental pollution. Volume 268(2021)Part B
• Publication Date: 2021-01-01
• Subjects: Polystyrene particles -- di-butyl phthalate -- Oxidative damage -- Combined pollution -- Toxic mechanism; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115870
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Hydrophobic microplastics with a relatively large surface area can act as carriers for pollutants and exert a series of indirect effects on crop plants. This study investigated the toxic effects of small polystyrene (SPS, 100–1000 nm) and large polystyrene (LPS, >10, 000 nm) microplastics, on lettuce under di-butyl phthalate (DBP) stress. The results indicated that single SPS, LPS, and DBP treatments significantly decreased lettuce biomass, and induced oxidative stress and damaged lettuce leaves and roots. According to Gaussian analysis, SPS or LPS could interact with DBP through van der Waals force, thereby reducing lettuce biomass and DBP enrichment in roots and leaves under combined treatments, increasing antioxidant enzyme activities and exacerbating oxidative stress and subcellular damage, compared to single DBP treatments. Observation using scanning electron microscopy demonstrated that polystyrene (PS) adhered to the root surfaces, which, in turn, caused physical blockage of the root pores. Cell membrane and wall damage was observed during PS and/or DBP exposures, as identified by transmission electron microscopy. Molecular docking illustrated that DBP and monobutyl phthalate could interact with superoxide dismutase residues through hydrogen bonding, π-π stacking, alkyl conjugation, and van der Waals forces. Interestingly, there were no statistical differences between the phytotoxicity of nano- and microplastics to lettuce. These findings showed that PS aggravated DBP-induced phytotoxicity. Graphical abstract: Image 1 Highlights: Polystyrene dramatically reduced DBP and MBP enrichment in lettuce leaves and roots. Polystyrene adhered on root surfaces and caused the physical blockage of root pores. DBP and MBP could interact with superoxide dismutase residues. Polystyrene aggravated DBP-induced phototoxicity.