From farm to fork: a multiscale investigation of TBP contamination in rye, unraveling detoxification mechanisms and food safety risks.

The presence of the organophosphate flame retardant tributyl phosphate (TBP) in agricultural systems threatens food safety, yet its accumulation and toxicological effects in food crops are poorly understood. This study examines the physiological and molecular responses of rye to TBP stress, focusing on grain safety. Under hydroponic and soil exposure (0-100 mg/L TBP), rye showed significant growth inhibition, including biomass reduction (up to 69.02%) and photosynthetic decline. Critically, TBP accumulated in edible grains (up to 0.17 mg/kg), causing a 27.52% decrease in thousand-kernel weight and developmental defects. Mechanistically, TBP bound to photosystem I proteins (-5.5 kcal/mol), induced oxidative stress (80.19% higher Malondialdehyde), and activated detoxification enzymes (glutathione S-transferase, ascorbate peroxidase). Degradation products were identified by LC-MS/MS, and multi-omics revealed metabolic reprogramming and enrichment of TBP-degrading rhizobacteria. These findings highlight TBP's entry into the food chain and its threat to grain quality, urging monitoring and mitigation strategies for cereal safety.