Divergent nitrogen-form preferences for vegetative growth and systemic pesticide translocation in sugarcane

Fertilizers and systemic insecticides are often applied together in sugarcane production, yet how nitrogen form affects pesticide delivery remains unclear. Using hydroponic experiments integrated with transcriptomic and metabolomic analyses, we investigated how nitrogen forms regulate imidacloprid uptake and translocation. Although ammonium (NH 4 + ) preferentially supported vegetative growth, nitrate (NO 3 - ) markedly enhanced acropetal imidacloprid transport, increasing whole-shoot imidacloprid accumulation by 336.37% relative to the control, independently of medium pH. Nitrate also enhanced root activity and triggered coordinated transcriptional and metabolic reprogramming. It upregulated genes involved in nitrogen assimilation ( NIA1 and NiR ) and transmembrane transport ( ABCB11 ). In parallel, it reshaped glutamate/asparagine metabolism and glutathione-associated redox buffering. Together, these responses established an active root-to-shoot transport network, thereby enhancing imidacloprid delivery to the upper leaves. Our findings reveal distinct nitrogen-form preferences for vegetative growth and systemic pesticide translocation, supporting stage-specific nitrogen management and targeted pesticide-fertilizer practices for coordinating vegetative growth with pest control in sugarcane.