The growth-blocking peptide is a dual regulator of development and immunity with biocontrol potential in Spodoptera frugiperda (Lepidoptera: Noctuidae)

• Published in: Pesticide biochemistry and physiology Vol. 204; p. 106097
• Main Authors: Liu, Feng, Qi, Wen-Xuan, Liu, Fang-Fang, Ren, Hai-Yan, Zhang, Bang-Xian, Rao, Xiang-Jun
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-09-2024
• Subjects: Amino Acid Sequence; Animals; Beauveria - physiology; Biocontrol; Entomopathogen; Growth-blocking peptide; Insect immunity; Insect Proteins - genetics; Insect Proteins - metabolism; Larva - drug effects; Larva - immunology; Pest Control, Biological - methods; Spodoptera - drug effects; Spodoptera - immunology; Spodoptera frugiperda; Spodoptera frugiperda; Entomopathogen; Insect immunity; Growth-blocking peptide; Biocontrol
• ISSN: 0048-3575; 1095-9939; 1095-9939
• DOI: 10.1016/j.pestbp.2024.106097

Insect growth-blocking peptides (GBPs) are a family of cytokines found in several insect orders and are known for their roles in regulating development, paralysis, cell proliferation, and immune responses. Despite their diverse functions, the potential of GBPs as biocontrol targets against the pest Spodoptera frugiperda (Lepidoptera: Noctuidae) has not been fully explored. In this study, S. frugiperda GBP (SfGBP) was identified and functionally characterized. SfGBP is synthesized as a 146 amino acid proprotein with a 24 amino acid C-terminal active peptide (Glu123-Gly146). Predominant expression of SfGBP occurs in fourth to sixth instar larvae and in the larval fat body, with significant upregulation in response to pathogens and pathogen-associated molecular patterns. Injection of the synthetic active peptide into larvae induced growth retardation, delayed pupation, and increased survival against Beauveria bassiana infection. Conversely, RNA interference-mediated knockdown of SfGBP resulted in accelerated growth, earlier pupation, and decreased survival against B. bassiana infection. Further analysis revealed that SfGBP promoted SF9 cell proliferation and spreading, enhanced bacteriostatic activity of larval hemolymph, and directly inhibited germination of B. bassiana conidia. In addition, SfGBP enhanced humoral responses, such as upregulation of immunity-related genes and generation of reactive oxygen species, and cellular responses, such as nodulation, phagocytosis, and encapsulation. These results highlight the dual regulatory role of SfGBP in development and immune responses and establish it as a promising biocontrol target for the management of S. frugiperda.
The growth-blocking peptide in Spodoptera frugiperda is a potential biocontrol target, acting as a dual regulator of both development and immunity. [Display omitted]
•Identification of growth-blocking peptide SfGBP in Spodoptera frugiperda.•Injection of SfGBP caused growth retardation and increased immunity.•Knockdown of SfGBP caused accelerated growth and decreased immunity.•SfGBP promotes cell proliferation and spreading.•SfGBP increases humoral and cellular immune responses.