Identification and Expression Profiles of Candidate Sex Pheromone Biosynthesis Genes by the Transcriptome Analysis of Sex Pheromone Glands in Spodoptera litura and Spodoptera exigua

Like many insects, females of the Noctuid moth Spodoptera litura and Spodoptera exigua release chemical signals to attract males from a long distance for successful mating. In this study, 98 and 86 genes related to the sex pheromone biosynthesis of S. litura and S. exigua were identified. The tissue expression profiles of highly expressed genes in sex pheromone glands (PGs) were further examined by real-time quantitative polymerase chain reaction. The results displayed that only SlitDes5 and SexiDes5 gene were specifically and significantly overexpressed in the PGs of S. litura and S. exigua. The functional study of SlitDes5 gene showed that RNA interference reduced its expression level by 49.42%. In addition, the content of the sex pheromones of S. litura, Z9E11-14:OAc, Z9E12-14:OAc, E11-14:OAc, and Z9-14:OAc, decreased by 41.98% on average. Our findings provide a basis for better understanding the key genes that affect the biosynthesis of sex pheromones and for determining potential gene targets for pest control strategies.