R-napropamide drives herbicide-induced cadmium accumulation in Arabidopsis via enantiomer-specific nutrient crosstalk

Soil heavy metal contamination has emerged as a critical global environmental issue due to industrialization, posing severe threats to human health. Notably, heavy metal pollution and herbicide application frequently coexist in agricultural systems. This study reveals enantiomer-specific effects of the widely used herbicide napropamide (NAP) on plant growth and cadmium (Cd) accumulation in Arabidopsis thaliana. Compared to the control, R-NAP enhanced plant growth while S-NAP exhibited inhibitory effects. Intriguingly, R-NAP treatment increased Cd accumulation by 14 % and 90 % relative to the control and S-NAP, respectively. Furthermore, R-NAP significantly elevated the contents of macronutrients (nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg)) and micronutrients (iron (Fe), zinc (Zn)) by 1.05-1.3-fold and 1.25-1.82-fold compared to the control and S-NAP treatments. Mantel test and structural equation modeling (SEM) identified significant correlations between Cd and nutrients (N, P, Fe, Zn), with N and P directly/indirectly influencing Cd accumulation via Fe/Zn regulation. Transcriptomic analysis coupled with cross-domain network modeling uncovered core genes co-regulating nutrient uptake and Cd accumulation, including NRT1.2, NRT1.5, PHT3.2, ABCC9, and YSL6. Molecular docking confirmed strong binding affinities between NAP enantiomers and these transporter proteins. Our findings demonstrate that nutrient uptake dynamics mediate herbicide-induced Cd accumulation, providing novel insights for optimizing herbicide-nutrient management to mitigate crop metal uptake in contaminated farmlands.