Integrated omics analysis reveals transcriptional and metabolic reprogramming underlying cotton responses to decabromodiphenyl ethane stress

The increasing use of decabromodiphenyl ethane (DBDPE), a novel brominated flame retardant (NBFR), has raised growing concerns regarding its potential environmental risks. Cotton ( Gossypium hirsutum L.) is an important non-food cash crop with potential for phytoremediation, which may serve as a promising candidate for remediating DBDPE-contaminated environments. However, the mechanisms underlying DBDPE accumulation and plant responses remain poorly understood. In this study, cotton plants hydroponically exposed to DBDPE at 0 mg/L (control), 100 mg/L (environmental concentration), and 200 mg/L (high-exposure concentration) showed concentration-dependent phytotoxic effects on cotton plants. Liquid chromatography-mass spectrometry analysis revealed substantial DBDPE accumulation in roots, stems and leaves. Transmission electron microscopy revealed ultrastructural damage in root and leaf cells. Transcriptomic analysis showed that DBDPE exposure at the environmentally relevant concentration induced the expression of antioxidant-related genes. Consistently, oxidative stress assays demonstrated concentration-dependent increases in levels of oxidative damage markers. Integrated transcriptomic and metabolomic analysis revealed a coordinated detoxification network in response to environmentally relevant DBDPE exposure. Flavonoid biosynthesis and glutathione metabolism contributed to reactive oxygen species (ROS) scavenging, while phenylpropanoid and linoleic acid metabolism were associated with the coordinated regulation of antioxidant accumulation. This study provides mechanistic insights into plant adaptation to NBFR exposure and lays the groundwork for assessing the ecological risks of DBDPE and exploring the phytoremediation potential of cotton in NBFR-contaminated agricultural environments.