Chen Juanni, Mao Shuyu, Xu Zhifeng, Ding Wei
Laboratory of Natural Product Pesticides, College of Plant Protection, Southwest University Chongqing 400715 China
RSC Adv. 2019 Jan 29;9(7):3788-3799. doi: 10.1039/c8ra09186b. eCollection 2019 Jan 25.
The substantial antimicrobial efficacy of nanoparticles against phytopathogens has been extensively investigated for advanced agricultural applications. However, few reports have focused on soilborne pathogenic bacteria. The aim of this study was to obtain sustainably synthesized copper oxide nanoparticles (CuONPs) using papaya leaf extracts and investigate the bactericidal activity of these CuONPs against , the cause of bacterial wilt, under laboratory and greenhouse conditions. The results showed that CuONPs possessed strong antibacterial activity and that all were killed after exposure to 250 μg mL CuONPs. CuONPs could interact with bacterial cells to prevent biofilm formation, reduce swarming motility and disturb ATP production. Ultrastructural observations by transmission electron microscopy (TEM) revealed that after interactions with CuONPs, bacterial cells suffered significantly from nanomechanical damage to the cytomembrane, accompanied by the absorption of multiple nanoparticles. In addition, molecular studies identified the downregulation mechanism of a series of genes involving pathogenesis and motility. The control efficiency of CuONPs in tobacco bacterial wilt disease management under greenhouse conditions was verified by root irrigation application, demonstrating that as-prepared CuONPs significantly reduced the disease occurrence and disease index. Our studies focused on developing biosynthesized nanoparticles as a biocompatible alternative for soilborne disease management.
纳米颗粒对植物病原体的显著抗菌功效已针对先进农业应用进行了广泛研究。然而，很少有报告关注土壤传播的致病细菌。本研究的目的是使用木瓜叶提取物可持续合成氧化铜纳米颗粒（CuONPs），并在实验室和温室条件下研究这些CuONPs对青枯病病原菌的杀菌活性。结果表明，CuONPs具有很强的抗菌活性，在暴露于250μg/mL CuONPs后，所有病原菌均被杀死。CuONPs可与细菌细胞相互作用，以防止生物膜形成、降低群体运动性并干扰ATP产生。通过透射电子显微镜（TEM）进行的超微结构观察表明，与CuONPs相互作用后，细菌细胞的细胞膜受到显著的纳米机械损伤，同时伴有多个纳米颗粒的吸附。此外，分子研究确定了一系列涉及致病和运动的基因的下调机制。通过根灌施验证了CuONPs在温室条件下对烟草青枯病的防治效果，表明所制备的CuONPs显著降低了病害发生率和病情指数。我们的研究专注于开发生物合成纳米颗粒作为土壤传播病害管理的生物相容性替代品。
