RNAi-mediated CrebA silencing inhibits reproduction and immunity in Locusta migratoria manilensis

• Published in: Developmental and comparative immunology 2023-08, Vol.145, p.104711-104711, Article 104711
• Main Authors: Tang, Ya, Hu, Yao-Wen, Wang, Shao-Hua, Zhou, Min, Ding, Yan-Juan, Cai, Si-qi, Tang, Bin, Wang, Shi-Gui
• Format: Article
• Language: English
• Subjects: Animals; CrebA; Escherichia coli - metabolism; Female; Immunity; Insect Proteins - genetics; Insect Proteins - metabolism; Locusta migratoria - genetics; Locusta migratoria manilensis; Monophenol Monooxygenase - metabolism; Muramidase - metabolism; Reproduction; RNA - metabolism; RNA Interference
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2023.104711

Locusta migratoria manilensis is a major agricultural pest that causes severe direct and indirect damage to several crops. Thus, to provide a theoretical foundation for pest control, the role of CrebA in the reproduction and immune regulation of L. migratoria was investigated. CrebA is a bZIP transcription factor that critically regulates intracellular protein secretion. In this study, CrebA was widely expressed in the brain, fat body, integument, midgut, and reproductive tissues of different maturity stages of adult locusts, especially in the female fat body. RNA interfering (RNAi)-mediated silencing of CrebA inhibited locusts ovarian development, and key reproduction gene expressions, Vgs, VgRs, Chico, and JHAMT were downregulated. After the locusts were injected with Micrococcus luteus or Escherichia coli, M. luteus activated lysozyme expression, while the E. coli activated both phenol oxidase cascade and lysozyme expression. Furthermore, both bacteria stimulated the upregulation of the antimicrobial peptide genes DEF3 and DEF4. However, CrebA silencing is fatal to locusts infection with E. coli, with a mortality rate of up to 96.3%, and resulted in a significant decrease in the expression of DEF3 and DEF4 and changes in the activities of phenol oxidase and lysozyme of locusts infected by bacteria. Collectively, CrebA may be involved in diverse biological processes, including reproduction and immunity. CrebA inhibited locusts reproduction by regulating JH signaling pathway and inhibits the expression of immune genes TLR6, IMD, and AMPs. These results demonstrate CrebA seems to play a crucial role in reproduction and innate immunity. •CrebA is highly expressed in the fat body of adult female locusts.•CrebA silencing resulted in delayed and poor ovarian development in locusts.•Immune response of locusts was triggerd by Micrococcus luteus and Escherichia coli infection.•CrebA silencing suppressed TLR6, IMD, DEF3, and DEF4 mRNA expression of immune signaling pathways.