Effects of Biodegradable Poly (Butylene Adipate‐Co‐Terephthalate) Microplastics on Grain Quality and Defense Mechanism of Wheat

Biodegradable poly (butylene adipate‐co‐terephthalate) (PBAT) plastics are an important alternative to conventional plastics used in agriculture; PBAT microplastics (MPs) are found in agricultural soils. However, little is known about the effects of PBAT MPs on crop toxicity, especially on edible fruit. Here, the effects of environmentally relevant concentrations of PBAT MPs on the growth, grain quality, and related molecular mechanisms of wheat were investigated using a soil pot experiment. The results showed that PBAT MPs inhibited wheat growth, damaged the root ultrastructure, and decreased mineral levels; these phenotypic effects are consistent with omics evidence showing downregulation of the TCA cycle metabolism and genes involved in metal ion binding. As a defense response to PBAT MPs, grain starch and protein levels decreased by 39.06% and 18.44%, respectively, whereas soluble sugar levels increased by 13.36%. These changes can be attributed to the downregulation of tryptophan metabolism and upregulation of galactose metabolism. The present results indicate the adverse effects of biodegradable MPs on crops, which may have beneficial implications for human dietary health and nutritional intake.