Temporal multi-omics unravels quinclorac phytotoxicity and its alleviation by potassium persulfate in Nicotiana tabacum

Quinclorac, a widely used auxin-like herbicide, frequently causes severe and persistent phytotoxicity in rotational sensitive crops such as tobacco ( Nicotiana tabacum L.). Although chemical oxidation using potassium persulfate (KPS) is a promising approach for environmental remediation, the dynamic molecular responses underlying chronic quinclorac injury and KPS-associated alleviation remain poorly understood. In this study, aqueous degradation kinetics confirmed that KPS efficiently decomposed quinclorac following pseudo-first-order kinetics. Both hydroponic and pot experiments showed that KPS application effectively alleviated herbicide-induced leaf narrowing and growth retardation. Time-course transcriptomic and metabolomic profiling across three growth stages (T1, T2, and T3) revealed distinct chronological plant stress responses, characterized by early lipid peroxidation (T1), middle-stage impairment of the glutathione-dependent redox system (T2), and late-stage upregulation of ATP-binding cassette (ABC) transporters (T3), outlining a stepwise progression of toxic responses in tobacco leaves. Multi-omics co-expression analysis indicated that quinclorac exposure was correlated with altered auxin–ethylene–abscisic acid crosstalk involving transcription factor families, including WRKY and AP2/ERF, alongside perturbations in primary metabolism and nitrogen metabolism. Notably, in soil KPS treatment was accompanied by marked mitigation of these stress-related molecular alterations, partial preservation of endogenous hormone transcriptional homeostasis, and upregulation of gene networks associated with photosynthesis and primary metabolism. Overall, this study characterizes the temporal multi-omics footprint of quinclorac stress in tobacco and indicates that KPS application provides an effective, catalyst-free strategy to mitigate herbicide carryover toxicity to sensitive rotational crops in agricultural ecosystems.