Phosphoinositide-dependent kinase PDK, a key component of the insulin signaling pathway, plays an important role in the regulation of insect growth and development. However, the functional significance of the PDK gene in Tuta absoluta, a destructive invasive tomato leaf miner, remains unknown. In this study, we identified and characterized a PDK gene (designated TaPDK) and analyzed its physiological roles in molting and reproduction of T. absoluta. Our results showed that the TaPDK expression levels were elevated in the 5- and 6-day-old pupae before ecdysis and declined immediately after eclosion. TaPDK was predominantly expressed in the head, midgut and abdomen. When the TaPDK was knockdown, the larval-pupal molting and female reproduction were severely affected. Injecting dsRNA of TaPDK into 2-day-old female pupae resulted in severe phenotypic changes (cuticular shrinkage) in 31.29% of pupae, ultimately leading to death. Knockdown of TaPDK significantly reduced the 20E titer and chitin content and downregulated the expression levels of genes involved in the 20E pathway and chitin metabolism. Further investigation revealed that the suppression of TaPDK impaired ovarian development, resulting in significantly reduced fecundity and hatchability. In addition, the JH titer and vitellogenin content of TaPDK-deficient females were reduced, and the expression of Vg, VgR, and JH signaling pathway genes were significantly decreased. Collectively, our study provides a deep insight into the PDK-mediated regulation of pupal ecdysis and female reproduction in T. absoluta.

磷酸肌醇依赖性激酶 PDK 是胰岛素信号通路的关键组成部分，在昆虫生长发育的调节中起重要作用。然而，PDK 基因在 Tuta absoluta（一种破坏性入侵性番茄潜叶虫）中的功能意义仍然未知。在这项研究中，我们鉴定并表征了一个 PDK 基因 （命名为 TaPDK），并分析了其在 T. absoluta 蜕皮和繁殖中的生理作用。我们的结果表明，蜕皮前5 d和6 d龄蛹的TaPDK表达水平升高，羽化后立即下降。TaPDK 主要在头部、中肠和腹部表达。当 TaPDK 被敲低时，幼虫蛹的蜕皮和雌性繁殖受到严重影响。将 TaPDK 的 dsRNA 注射到 2 日龄的雌性蛹中导致 31.29% 的蛹出现严重的表型变化（表皮收缩），最终导致死亡。敲低 TaPDK 显著降低 20E 滴度和几丁质含量，下调参与 20E 通路和几丁质代谢的基因表达水平。进一步的研究表明，TaPDK 的抑制会损害卵巢发育，导致繁殖力和孵化率显著降低。此外，TaPDK 缺陷型雌株的 JH 滴度和卵黄蛋白原含量降低，Vg 、 VgR 和 JH 信号通路基因的表达显著降低。总的来说，我们的研究为 PDK 介导的 T. absoluta 蛹蜕皮和雌性生殖的调节提供了深入的见解。