LAUSR

Nano-delivery systems have been applied to deliver various synthetic/botanical pesticides to increase pesticide utilization efficiency and reduce pesticide application amount. Previous studies supported that the nanocarriers can help expand the insecticidal target of pesticides to include non-target pests. However, the potential mechanism underlying this interesting phenomenon is still not clear. Herein, a widely applied star polycation (SPc) nanocarrier was synthesized to construct a thiamethoxam (TMX) nano-delivery system. The SPc-based delivery system could promote the translocation of exogenous substances across the membrane of Sf9 cells, increase the cytotoxicity of TMX against Sf9 cells by nearly 20%, and expand the insecticidal target of TMX to include fall armyworms with a 27.5% mortality increase at a concentration of 0.25 mg/mL. Moreover, the RNA-seq analysis demonstrated that the SPc could up-regulate various transport-related genes, such as Rab, SORT1, CYTH, and PIKfyve, for enhanced cellular uptake of TMX. Furthermore, the stronger cell death in larvae treated with TMX/SPc complex was observed by adjusting the expression levels of death-related genes, such as Casp7, BIRC5, MSK1, and PGAM5. The SPc-based nano-delivery system improved the cellular uptake of TMX and expanded its insecticidal target by adjusting the expression levels of death-related genes. The current study mainly identified the transport and cell death genes related to nanocarrier-based insecticidal target expansion, which is beneficial for understanding the bioactivity enhancement by nano-delivery system. This article is protected by copyright. All rights reserved.