Stimulation effects of tricin, a rice-derived insect-resistant compound, on salivary gland transcriptome of brown planthopper Nilaparvata lugens (Stål)

In order to investigate how brown planthopper (BPH, Nilaparvata lugens) responds to the stimulation of tricin, an insect-resistant compound in rice, and reveal the transcriptional regulation mechanism behind it, this study systematically analyzed the transcriptional changes in salivary gland tissue of BPH under the stimulation of tricin using RNA-seq. The results showed that, compared with the blank control, 49 and 232 differentially expressed genes (DEGs) were found in the salivary glands of BPH after treatment with tricin for 6 h and 24 h, respectively, and 23 shared DEGs were found between both time points. The number of DEGs caused by long-term treatment of tricin was significantly higher than that caused by short-term treatment, and the expression levels of these genes also exhibited a temporal induction pattern. Further analysis by Gene Ontology (GO) functional annotation indicated that these shared DEGs were mainly involved in biological processes such as response to stimuli and response to stress. At the same time, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis further demonstrated that these genes were mainly concentrated in protein digestion and absorption and endocrine regulation and other related pathways. RT-qPCR analysis of shared DEGs confirmed that tricin stimulation could indeed induce the expression of trypsin, maltase and transporter-related genes in the salivary glands of BPH. These results will help to reveal the molecular mechanism of BPH response to tricin stimulation, and also indicate that trypsin and organic anion transporter LOC111045154 may serve as potential targets for future control of BPH.