Enhanced fungicidal activity and mechanism of pyraclostrobin nanoparticle with reactive oxygen species responsiveness against Rhizoctonia solani

• Published in: Journal of cleaner production 2023-10, Vol.421, p.138494, Article 138494
• Main Authors: Zhang, Ning, Hu, Wei, Hou, Ruiquan, Du, Pengrui, Miao, Xiaoran, Wang, Ruifei, Wu, Hao, Li, Shengnan, Li, Youzhi, Zhang, Zhixiang, Xu, Hanhong
• Format: Article
• Language: English
• Subjects: Antioxidant enzymes; Controlled release; Defense relative genes; Microbial community; Nanopesticide
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2023.138494

The frequent application of pesticides has caused adverse effects on humans and the environment. Stimuli-responsive nanoparticles can enhance the control efficacy of pesticides to pest insects or fungus and reduce impacts on non-target organisms. In the present work, 4-(hydroxymethyl) phenylboronic acid pinacol ester (PBAP) groups were conjugated onto β-cyclodextrin (β-CD) to form a H2O2-eliminating material (Ox-bCD), and then the nanoparticiles (PYR@OxbCD) loaded pyraclostrobin (PYR) were successfully fabricated by a nanoprecipitation. The prepared PYR@OxbCD had excellent reactive oxygen species (ROS) release dependency, and significantly enhanced fungicidal activity against Rhizoctonia solani in vitro. PYR@OxbCD could accurately release PYR at infected rice plants, providing a better control efficacy than PYR suspension concentrate (SC). The contact angle of PYR@OxbCD on leaves was reduced, and the spreading and antiphotolysis properties were increased, which may lead to an increase of deposition and a lower dissipation rate. Furthermore, the released PYR from PYR@OxbCD enhanced the activity of peroxidase (POD) and catalase (CAT), and up-regulated the expression of defense genes including PAL, PR10, CHI, CAT, GluPOD and AsPOD. PYR@OxbCD exhibited a much weaker effect on microbial abundance in rice cropping systems. The study provides an idea for smart delivery of fungicides to prevent plant pathogens and offers a more comprehensive view about the resistance of R. solani-infected rice triggered by PYR@OxbCD in levels of phenotype, enzymatic activity, gene expression, and microbiome.