LAUSR

BACKGROUND Spirotetramat is a tetramic acid derivative insecticide with novel modes of action for controlling Aphis gossypii Glover in the field. Previous studies have shown that long noncoding RNAs (lncRNAs) and cytochrome P450 monooxygenases (P450s) are involved in the detoxification process. However, the functions of lncRNAs in regulating P450 gene expression in spirotetramat resistance in A. gossypii are unknown. RESULTS In this study, we found CYP4CJ1, CYP6CY7, and CYP6CY21 expression levels to be significantly upregulated in a spirotetramat-resistant (SR) strain compared with a susceptible (SS) strain. Furthermore, knockdown of CYP4CJ1, CYP6CY7, and CYP6CY21 increased nymph and adult mortality in the SR strain following exposure to spirotetramat. Drosophila ectopically expressing CYP380C6, CYP4CJ1, CYP6DA2, CYP6CY7, and CYP6CY21 showed significantly decreased mortality after spirotetramat exposure, and CYP380C6, CYP4CJ1, and CYP6CY21 are putative targets of 6 lncRNAs. Silencing of lncRNAs MSTRG.36649.2/5 and MSTRG.71880.1 changed CYP6CY21 and CYP380C6 expression, altering the sensitivity of the SR strain to spirotetramat. Moreover, MSTRG.36649.2/5 did not compete for microRNA binding to regulate CYP6CY21 expression. CONCLUSION Our results confirm that CYP380C6, CYP4CJ1, CYP6DA2, CYP6CY7, and CYP6CY21 are potentially involved in the development of spirotetramat resistance in A. gossypii, and MSTRG.36649.2/5 and MSTRG.71880.1 likely regulate CYP6CY21 and CYP380C6 expression through other rather than the 'sponge effect' of competing for miRNA binding. Our results provide a favorable molecular basis for studying cotton aphid P450 genes and lncRNA functions in spirotetramat resistance development.