Uptake, translocation, and biotransformation of phthalate acid esters in crop plants: A comprehensive review

Phthalate acid esters (PAEs) are prevalent emerging contaminants in agricultural environments. The uptake of PAEs by crop plants has attracted extensive attention due to the risks posed to human health through transfer in food chains. Despite its importance, the interaction between PAEs and crop plants remains poorly understood. In this critical review, the occurrence of six priority control PAEs in various food crops grown in greenhouses and conventional farms is investigated, with detected concentrations reaching up to mg/kg (dry weight) levels. PAEs enter plants through roots, foliar gas, or foliar particle uptake. After entry, PAEs exhibit acropetal translocation from the root and basipetal translocation from the leaf. PAEs are transformed into various metabolites through hydroxylation, hydrolysis, and oxidation in phase I metabolism and further conjugated with biomolecules such as amino acids or sugars in phase II metabolism. Exposure to PAEs disrupts plant homeostasis and activated antioxidant enzymes to alleviate phytotoxicity. Dietary intake of PAEs-contaminated food crops presents potential risks to human health, particularly from fruit and root vegetables consumed by children, warranting specific attention. Furthermore, current knowledge gaps and future perspectives are proposed. This review provides a comprehensive assessment of the knowledge on the uptake, translocation, and transformation of PAEs in crop plants, emphasizing the need for an integrated investigation into the full life cycle of PAEs in plants to ensure food safety.