Guadipyr, a new insecticide, induces microbiota dysbiosis and immune disorders in the midgut of silkworms (Bombyx mori). (1st October 2021)

• Record Type: Journal Article
• Authors: Hou, Jiayin; Yu, Jianzhong; Qin, Zhaohai; Liu, Xinju; Zhao, Xueping; Hu, Xiuqing; Yu, Ruixian; Wang, Qiang; Yang, Jingying; Shi, Yan; Chen, Liezhong
• Is Part Of: Environmental pollution. Volume 286(2021)
• Publication Date: 2021-10-01
• Subjects: Guadipyr -- Midgut microbiota -- Immune disorder -- Silkworm; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117531
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Guadipyr, which combines neonicotinoid and semicarbazone functional groups in one molecule, exhibits good activity on several pests and high acute and chronic toxicity to silkworms ( Bombyx mori ). In this report, the effects of low-dose guadipyr on the midgut microbiota and immune system of silkworms were studied. Results showed that the structure and richness of the midgut microbiota of silkworms were altered after being treated with 5.25 mg/L (1/10 of LC50 ) of guadipyr. The abundance of Pseudomonas was evidently increased, whereas Curvibacter was substantially reduced, which might be related to the growth and immunity of silkworms. The expression of key genes in the Toll, IMD, and JAK/STAT pathways, which ultimately led to the downregulation of antimicrobial peptide genes ( AMPs ), such as CecA, Defensin1, Leb, and glv2, was reduced upon guadipyr exposure. Simultaneously, the suppression of steroid hormone 20-hydroxyecdysone receptor and response genes, such as BR-C Z4, was detected in the exposed groups. The decreased expression of these immune regulatory pathway-related and 20-hydroxyecdysone signal pathway-related genes indicated that the immune system of silkworms was affected by low-dose guadipyr. Our results revealed the negative effects of guadipyr on silkworms and highlighted the unneglectable toxicity of low-dose guadipyr to this economic insect. Given the risk, it is necessary to control the application of guadipyr in or around the mulberry fields. Graphical abstract: Image 1 Highlights: Guadipyr decreased the survival rate and body weight of silkworms. At low doses, guadipyr reduced the mRNA expressions of antimicrobial peptides. Guadipyr dysregulated the expression of genes in several immune-related pathways. Guadipyr disturbed the midgut microbiota in silkworms. Abstract : Capsule: Low-dose exposure of new insecticide guadipyr induces microbiota dysbiosis and immune disorders in the midgut of silkworms; thus, it is necessary to control the application of guadipyr in or around the mulberry fields.