Biodegradable Polybutylene Adipate Terephthalate (PBAT) Microplastics Cause More Toxic Effects on Winter Wheat in the Presence of Trichoderma citrinoviride and 2,4-D than Low-Density Polyethylene (LDPE)

The increasing contamination of agricultural soils with microplastics (MPs) represents an emerging environmental challenge. While conventional plastics such as low-density polyethylene (LDPE) persist for decades, biodegradable alternatives like polybutylene adipate terephthalate (PBAT) are promoted as eco-friendly solutions. However, their environmental safety for crop plants and soil microbiota remains poorly understood. In this study, we evaluated the effects of LDPE and PBAT microplastics (1% w/w) on the growth and physiological state of winter wheat (Triticum aestivum L.) cultivated in soil, either alone or in combination with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and the plant-beneficial fungus Trichoderma citrinoviride. Growth parameters (root and shoot length and mass), germination index, chlorophyll content, antioxidant enzyme activity, and lipidomic profiles of wheat were assessed. PBAT stimulated biomass accumulation but simultaneously triggered oxidative stress and remodeled membrane phospholipids, indicating physiological disturbance. T. citrinoviride enhanced wheat growth and mitigated oxidative stress under non-contaminated conditions; however, its beneficial effect was generally suppressed in the presence of PBAT and/or 2,4-D. The results suggest that, despite its biodegradability, PBAT may pose a higher phytotoxic potential than conventional LDPE, particularly by altering oxidative balance and membrane lipid composition in wheat.