Detoxification mechanisms of cotton in response to tetrabromobisphenol A stress revealed by integrated omics analysis

Tetrabromobisphenol A (TBBPA), a widely used brominated flame retardant, is increasingly detected in the environment. Cotton (Gossypium hirsutum), a potential phytoremediation species, may play a role in mitigating such pollutants in soil, but its accumulation and response to TBBPA remains unclear. In the study, cotton seedlings exposed to TBBPA showed concentration-dependent inhibition, with more pronounced effects at higher concentrations. Liquid chromatography-mass spectrometry (LC-MS) revealed preferential TBBPA accumulation in roots followed by translocation to stems and leaves, showing a time-dependent accumulation pattern. Cellular damage was observed in both roots and leaves, with more severe ultrastructural damage in root tissues. RNA sequencing (RNA-seq) analysis identified significant activation of oxidative stress-related pathways, including hydrogen peroxide catabolism and peroxidase activity, while physiological measurements confirmed concentration-dependent elevations in H₂O₂, O₂^•-, and MDA levels, collectively demonstrating TBBPA-induced oxidative stress in cotton. Integrated transcriptomic and metabolomic analyses showed activation of multiple defense pathways, particularly flavonoid biosynthesis, which appears to function in reactive oxygen species scavenging. These findings enhance our understanding of plant detoxification mechanisms towards environmental pollutants like TBBPA and provide valuable insights for the development of phytoremediation strategies for brominated flame retardant contamination.