A novel lncRNA PDG1 targets NADP-ME to modulate TCA cycle and JH in Aspongopus chinensis diapause

Diapause is essential for insect survival under adverse environmental conditions and plays a crucial role in regulating reproduction. However, the role of long non-coding RNAs (lncRNAs) in this process remains unclear. In this study, we investigated the function of lncRNAs in the diapause of Aspongopus chinensis. A total of 28,360 lncRNAs were identified across the transcriptomes, with 814 upregulated and 512 downregulated during diapause. Analysis revealed 48 key mRNAs regulated by these lncRNAs, primarily associated with energy metabolism. Among them, the NADP+-dependent malic enzyme (NADP-ME) gene was notably enriched in these pathways. Knockdown of NADP-ME resulted in decreased pyruvate levels and TCA activity. We identified a novel lncRNA, PDG1, which regulates NADP-ME expression, and RNA interference targeting PDG1 increased NADP-ME levels, leading to enhanced pyruvate levels and elevated TCA cycle activity, with dual luciferase assays confirming that PDG1 directly targeted NADP-ME and downregulated its expression. Furthermore, secondary structure analysis revealed that PDG1 exhibited significantly lower free energy compared to NADP-ME, with fewer hairpins and stem-loops. These findings highlight PDG1's critical role in regulating TCA cycle activity by targeting NADP-ME during A. chinensis diapause, revealing a novel mechanism through which lncRNAs modulate metabolic pathways to control insect diapause.