Abstract
Utilizing nanotechnology for pesticide delivery can enhance their uptake and distribution in plants, thereby boosting pesticide efficiency. Fluazinam, a highly effective broad-spectrum fungicide with unique mode of action, is hindered by its poor systemic conductivity, limiting its field control efficacy. In this study, fluazinam-loaded nanocapsules were developed, which exhibited significantly higher inhibitory activity against various Phytophthora species compared to the commercial suspension concentrate. Notably, the nanocapsules demonstrated pronounced effects on reducing ATP content in Phytophthora capsici and effectively controlled pepper blight and cucumber downy mildew. Tracking the distribution of fluorescein isothiocyanate (FITC) fluorescein-labeled fluazinam nanocapsules revealed their presence in roots seven days after treatment. High-performance liquid chromatography (HPLC) analysis confirmed the easy absorption and transport of fluazinam nanocapsules by pepper plants. Moreover, treatment with fluazinam nanocapsules significantly increased the expression of two exocytosis genes, FACP and RABF2a, in pepper tissues. Lastly, fluazinam nanocapsules were found to enhance the relative abundance of beneficial bacteria in the soil microbial community. This study presents a promising approach to enhance the upward transport capability of non-systemic pesticides, offering novel insights into their application and improved efficacy.