Silencing of <i>NlELO10</i> Affects Lipid Metabolism in Brown Planthopper

Fatty acid elongase (ELO) serves as the rate-limiting condensing enzyme in the initial step of the fatty acid elongation process. Among the ELO family members in the brown planthopper (Nilaparvata lugens), NlELO10 is essential for the development and physiology of N. lugens. However, the specific role and regulatory mechanisms of NlELO10 in lipid metabolism in N. lugens remain poorly understood. This study aimed to elucidate the effects of NlELO10 on lipid metabolism by employing RNA interference (RNAi) to silence the NlELO10 and utilizing lipidomics to analyze lipid composition and content changes following gene silencing. Lipidomic analysis revealed 32 differentially expressed lipid metabolites in N. lugens after NlELO10 knockdown. Among these, the levels of 3 phosphatidylcholines (PCs), 8 phosphatidylethanolamines (PEs), and 1 diacylglycerol (DG) were significantly elevated, whereas the levels of 20 triacylglycerols (TG) decreased significantly. The synthesis and metabolism of these differential lipid metabolites involve the coordinated action of multiple key enzymes, including acyl-CoA synthetase (FACS), diacylglycerol acyltransferase (DGAT), and phosphatidic acid phosphatase (PAP). To further validate the lipidomic findings, we performed real-time quantitative polymerase chain reaction (RT-qPCR) to examine the expression levels of genes encoding these metabolic enzymes. The gene expression patterns were consistent with the lipidomic data, supporting the involvement of these enzymes in the observed metabolic alterations. In conclusion, the silencing of NlELO10 disrupted the lipid composition and metabolism of N. lugens, potentially impairing physiological processes and leading to growth anomalies or mortality. These findings provide valuable insights into the functional role of NlELO10 in lipid metabolism and offer a theoretical foundation for identifying key lipid synthesis genes as targets for pest management strategies.