TaPIK3AP Regulates Female Reproduction in Tuta absoluta Through Juvenile Hormone-, Vitellogenin-, and TOR-Related Signaling

Tuta absoluta is a globally significant invasive pest that has rapidly developed resistance to multiple classes of insecticides, highlighting the critical need for RNA interference (RNAi) targets for sustainable pest management. The insulin signaling pathway is a key regulator of insect reproduction; however, the role of PIK3AP, an adaptor protein that links receptor tyrosine kinases to the PI3K-Akt signaling pathway, remains poorly understood in Lepidopteran pests. In this study, TaPIK3AP was identified in T. absoluta, exhibiting elevated expression levels in the heads of female adults and during the early reproductive period. RNAi-mediated knockdown of TaPIK3AP reduced fecundity by 76%, decreased egg hatching rate by 43%, shortened the oviposition period by two days, and caused pronounced ovarian atrophy accompanied by impaired yolk deposition. Mechanistically, knockdown of TaPIK3AP led to the suppression of Vg and VgR expression, a reduction in juvenile hormone (JH) titer, downregulation of JH signaling genes, and a significant decrease in the transcript levels of key components of the target of rapamycin (TOR) pathway, including mTOR, Rheb, and S6K. These findings demonstrate that TaPIK3AP integrates Vg, JH, and TOR signaling pathways to regulate female reproduction in T. absoluta, thereby identifying it as a potential molecular target for RNAi-based sustainable pest management strategies.