Starvation compromises the immunity of Helicoverpa armigera larvae by reducing 20-hydroxyecdysone levels
Zhang, Lin-Jie; Zhang, Ming-Ming; Liu, Xu-Sheng; Jing, Yu-Pu; Wang, Jia-Lin
Entomologia Generalis Volume 45 Number 3 (2025), p. 797 - 806
publié: Aug 19, 2025
publication en ligne: Jun 2, 2025
manuscrit accepté: Mar 7, 2025
révision final du manuscrit reçu: Mar 8, 2025
révision du manuscrit demandée: Dec 24, 2024
manuscrit reçu: Sep 19, 2024
ArtNo. ESP146004503018, Prix: 29.00 €
Abstract
The innate immunity of insects relies on the nutritional intake and hormone regulation. Previously, nutrition emerging as a pivotal factor, has been extensively reported to play a crucial role in promoting insect innate immunity. However, the regulatory mechanisms governing the interaction between nutrition and endocrine hormone remain poorly elucidated. The present study uses the cotton bollworm Helicoverpa armigera as a model organism to demonstrate that food deprivation increases the susceptibility of H. armigera larvae to pathogens. This heightened susceptibility is likely due to a reduction in antibacterial and phenoloxidase (PO) activity, coupled with impairments in phagocytosis, nodule formation, and encapsulation, as well as the downregulation of immunity-related genes expression in the fat body under starvation conditions. Moreover, food deprivation facilitates the nuclear translocation of the transcription factor Forkhead box O (FoxO), leading to the suppression of shade expression and a consequent reduction in 20E titer. Furthermore, 20E promotes the expression of genes involved in the Toll and Imd signaling pathways and increases the survival rates of starved larvae following pathogen exposure. Our findings indicate that 20E mediates starvation-induced immunosuppression in these larvae. The present study provides valuable insights into the tripartite interactions between starvation, 20E, and immune responses, which may be critical for developing effective insect population management strategies.
Mots-clefs
nutritional intake • humoral immunity • cellular immunity • shade • ecdysone • cotton bollworm