Transcriptomic and metabolomic profilings reveal the mechanism of related metabolites and gene regulatory networks of quinoa leaves to Spodoptera exigua feeding during flowering periods

The transcriptional response of plants to insect attacks involves dynamic signaling and synthetic reprogramming, which change over time. To elucidate the defensive response of quinoa to feeding by S. exigua, quinoa leaves were fed on by S.exigua for 5, 15, 30 and 60 min, and the transcriptomes and metabolomes were compared with those of uneaten control. When S.exigua fed on quinoa leaves for 15 min, the expression of CqMYB44L1 and CqMYB44L2 underwent stronger and faster changes, closely related to jasmonic acid. The quercetin content gradually increased with longer feeding durations, JA content was lowest at 15 min. DEGs were associated with plant hormone signal transduction and alpha-linolenic acid metabolism, which are related to quinoa resistance to S.exigua. Subcellular localization indicates CqMYB44L1 and CqMYB44L2 located in the nucleus and had transcriptional activity. Overexpression of CqMYB44L1 and CqMYB44L2 increased JA content in Arabidopsis leaves, and resulted in JA-mediated resistance to S.exigua feeding.