The effects of single and combined pollution of PE microplastics and antibiotics in soil on wheat (Triticum aestivum L.) seedlings

Both PE and antibiotics accumulate in agricultural soil systems over time and can affect plant growth and development. However, the single and combined contamination of PE with antibiotics (OTC, SM2) on wheat (Triticum aestivum L.) seedlings growth is not well studied. In this study, we evaluated the phytotoxic effects of PE (0.2%, 1%, 2%, 5% w/w) alone and in combination with OTC and SM2 (1 mg·kg ^− 1 、10mg·kg ^− 1 ) for 28d on the growth of wheat seedlings, chlorophyll, N and C contents, and antioxidant status through a pot experiment. toxicity effects. The results showed that biomass, plant height and root length exhibited dose-dependent toxicity under PE exposure alone and in combination with antibiotics (OTC or SM2). Malondialdehyde (MDA) content as well as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in the aboveground increased with increasing concentrations of PE, OTC and SM2, with SOD activity decreasing at 5% PE and PE + OTC compliance treatments. These results suggest that single and combined contamination pairs of PE and antibiotics (OTC, SM2) inhibit wheat growth, reduce chlorophyll production, exacerbate lipid peroxidation, and affect or even destroy the antioxidant system. Moreover, wheat seedlings were generally more sensitive to SM2 than OTC.