Kong Xinyan, Xie Ying, Cao Ying, Li Yujing, Zhang Yujie, Zou Zhiwen, Xia Bin, Xin Tianrong
School of Life Sciences, Nanchang University, Nanchang, China.
Insect Mol Biol. 2025 Jun;34(3):394-408. doi: 10.1111/imb.12978. Epub 2024 Dec 6.
Adipokinetic hormone (AKH), a crucial neuropeptide, participates in the important physiological processes by specially binding to its receptor to activate the AKH signalling pathway. AKH regulates energy metabolism. However, it remains unknown whether AKH affects larval development and adult reproduction by influencing energy metabolism. In the present study, the AKH was identified from Panonychus citri and contained the conserved functional domain 'Q-[LIV]-[NT]-F-[ST]-X (2)-W' that characterises the AKH family. The relative expression levels of PcAKH revealed different patterns of AKH expression at different developmental stages of P. citri. Feeding of double-standard RNA against PcAKH induced decreased fecundity and reduced survival, which was accompanied by the down-regulation of vitellogenin gene expression. In addition, after silencing the PcAKH, lipid metabolism and carbohydrate homeostasis were disrupted, manifested by increased body width and weight, and fasting phenomenon. Further investigation found that compared with the control, physiological changes in trehalose and triglyceride contents were accompanied by variations in the mRNA expression levels of genes related to lipid metabolism and carbohydrate metabolism. The disorder of lipid and carbohydrate metabolism may affect adult female reproduction, which may lead to insufficient vitellogenin deposition. Moreover, the silencing of PcAKH seriously affected the growth and development of larvae, which was manifested as delayed development period and difficulty in moulting. Conclusively, all these results in current study demonstrated that double-stranded RNA silencing system targeting PcAKH effectively inhibited larval development and female fecundity by disturbing lipid and carbohydrate metabolism, and PcAKH is a specific RNAi target for control of P. citri in the design and development of biopesticide in sustainable agriculture.
脂肪动激素（AKH）是一种关键的神经肽，通过特异性结合其受体激活AKH信号通路来参与重要的生理过程。AKH调节能量代谢。然而，AKH是否通过影响能量代谢来影响幼虫发育和成虫繁殖仍不清楚。在本研究中，从柑橘全爪螨中鉴定出AKH，其含有表征AKH家族的保守功能域“Q-[亮氨酸/异亮氨酸/缬氨酸]-[天冬酰胺/苏氨酸]-F-[丝氨酸/苏氨酸]-X（2）-W”。PcAKH的相对表达水平揭示了柑橘全爪螨不同发育阶段AKH表达的不同模式。喂食针对PcAKH的双链RNA导致繁殖力下降和存活率降低，同时伴随着卵黄原蛋白基因表达的下调。此外，沉默PcAKH后，脂质代谢和碳水化合物稳态受到破坏，表现为体宽和体重增加以及禁食现象。进一步研究发现，与对照相比，海藻糖和甘油三酯含量的生理变化伴随着脂质代谢和碳水化合物代谢相关基因mRNA表达水平的变化。脂质和碳水化合物代谢紊乱可能影响成年雌性的繁殖，这可能导致卵黄原蛋白沉积不足。此外，沉默PcAKH严重影响幼虫的生长发育，表现为发育时期延迟和蜕皮困难。总之，本研究的所有这些结果表明，靶向PcAKH的双链RNA沉默系统通过扰乱脂质和碳水化合物代谢有效地抑制了幼虫发育和雌性繁殖力，并且在可持续农业生物农药的设计和开发中，PcAKH是控制柑橘全爪螨的特定RNAi靶标。
