Silencing LsAtg8 reduces female fecundity and elevates Wolbachia density in embryos of the rice planthopper Laodelphax striatellus

BACKGROUND: Autophagy is essential for insect reproduction and endosymbiont homeostasis, with Atg8 serving as a key autophagy-related gene. However, the specific role of LsAtg8 in reproduction and endosymbiont regulation in Laodelphax striatellus has not been fully examined. RESULTS: In this study, we discovered that LsAtg8 is expressed at higher levels in the fat body and ovaries of L. striatellus compared to other autophagy-related genes, regardless of endosymbiont Wolbachia infection status. Knockdown of LsAtg8 using RNA interference significantly reduced female fecundity and delayed oocyte development in Wolbachia-infected females, but not in uninfected females. RNA-seq analysis revealed that LsAtg8 interference caused significant changes in the fatty acid metabolism pathway in the ovary, and the expression of several genes, including trifunctional enzyme subunit alpha (HADHA), fatty acid synthase (FAS) and acyl-CoA delta (11) desaturase (FADΔ11), was altered. Additionally, LsAtg8 silencing increased Wolbachia levels in embryos and altered its dynamics of density during the development of nymphs without affecting the lifespan or reproductive capacity of the offspring. CONCLUSION: These findings suggest a multifaceted role for Atg8 in the host-symbiont system and provide insights into pest management strategies targeting endosymbionts. © 2026 Society of Chemical Industry.