Metabolomics Reveals Antioxidant Stress Responses of Wheat ( L.) Exposed to Chlorinated Organophosphate Esters.

In this study, wheat ( L.) was exposed to three of the most typical chlorinated organophosphate esters (OPEs), which are widely present in farmland soil, at environmental concentrations to assess their accumulation, disruption on metabolism, and oxidative stress in wheat. The three OPEs accumulated distinctly in the root and then translocated to the shoot. After exposure for 7 days, the content of chlorophyll decreased, while the levels of carotenoid and activities of antioxidases, malonaldehyde, and reactive oxygen species increased significantly in both the root and shoot, indicating that the target OPEs caused significant oxidative stresses and affected photosynthesis in wheat. Untargeted metabolomics revealed concentration- and species-dependent metabolic responses of the three OPEs. Saccharides were downregulated, which might be due to the reduced photosynthesis activities. On the other hand, the chlorinated OPEs induced increases in respiration and antioxidative metabolites, revealing that the antioxidant system of wheat was active in scavenging ROS. The disturbance of tris(1,3-dichloro-2-propyl)phosphate on the metabolisms in wheat tissues was the strongest. These results contribute to the food safety and crop quality assessment of chlorinated OPEs and clarify the underlying mechanisms of their phytotoxicities.