Bismuth-selenium nanocomposite clusters inhibit tobacco bacterial wilt by disrupting bacterial morphology and promoting vegetative oxidative phosphorylation

Abstract

Tobacco bacterial wilt significantly impacts tobacco yield and quality, despite traditional control methods such as chemical fungicides and resistant cultivar breeding. However, these approaches suffer from limitations including monotonousness, residue concerns, and lengthy breeding cycles. In search of alternative solutions, nanomaterials have emerged as promising agents for enhancing agricultural productivity. Bismuth (Bi), a stable metal element with potent antibacterial properties, can effectively inhibit bacterial infections. Selenium (Se), an essential trace element for plants, exists in organic forms like selenocysteine within plants and enhances stress resistance. In this study, we designed cluster-like Bi-Se nanoparticles (Bi-Se NPs) by combining lamellar Bi NPs and spherical Se NPs via electrostatic interaction under nitrogen protection using a redox method. The optimal dosage was determined to be 128 ± 5 μg/mL based on antibacterial inhibition tests. Application of Bi-Se NPs through root irrigation increased selenium and reducing sugar contents in tobacco leaves, indicating a substantial nutrient boost in the plant body. Multi-omics analysis of the leaves revealed significant upregulation of succinic acid and flavin mononucleotide (FMN), components of the oxidative phosphorylation pathway. This upregulation enhanced pathway efficiency, accelerated oxygen and ATP production in leaves, and notably improved metabolic efficiency, thereby fostering tobacco growth and development. Furthermore, toxicity evaluations confirmed the non-toxic nature of Bi-Se NPs to mice. Collectively, these findings offer valuable insights and support for the management and yield enhancement of nanoscale agricultural systems.