Transcriptomic analyses revealed detoxification genes responsive to solanine treatment in Phthorimaea operculella

Phthorimaea operculella attacks potatoes worldwide, causing great losses in potatoes' quantity and quality. P. operculella feed on potatoes with a relatively high concentration of steroidal glycoalkaloids called solanine, which potatoes produce as secondary metabolites. The potential genes involved in solanine‐induced response in P. operculella were identified by performing next‐generation sequencing and Illumina RNA‐seq analysis on solanine‐treated P. operculella to explore differentially expressed genes. Four major families of detoxification enzymes were identified, including 71 cytochrome P450 monooxygenases (CYPs), 22 glutathione S‐transferases (GSTs), 58 esterases (ESTs) and 16 UDP‐glucuronosyltransferases (UGTs). The Illumina RNA‐Seq data showed 2875 and 1625 differentially expressed genes (DEGs) from the P. operculella larvae after exposure to the LC25 and LC75 of solanine compared with the untreated controls. Furthermore, 21 upregulated DEGs, including 13 CYPs, 3 GSTs, 4 ESTs and 1 UGT, and 20 downregulated DEGs, including 5 CYPs, 3 GSTs, 9 ESTs and 3 UGTs, were detoxification genes that may be related to solanine‐induced response and needed to be further verified. The RT‐qPCR results among the six upregulated P450 unigenes after solanine treatment were consistent with RNA‐Seq data, confirming the accuracy and reproducibility of the gene expression profiles generated from RNA‐seq. This study provides new information about the detoxification genes involved in solanine‐induced response in P. operculella.