“…At present, genomes and transcriptome data of many monoterpenoid indole alkaloidproducing plants, such as O. pumila, Catharanthus roseus, Camptotheca acuminata, and Nothapodytes nimmoniana, provided the foundation for understanding the biosynthesis and regulatory components of plant-specialized metabolites, followed by molecular characterization and functional validation of candidate genes (Kellner et al, 2015;Rather et al, 2018;Kang et al, 2021;Rai et al, 2021). At present, a few genes-encoding key enzymes, such as OpTDC, OpTDC2, OpSTR, OpCPR, OpG10H, OpSLS, OpLAMT, in the CPT biosynthetic pathway and several transcription factors (TFs), such as OpMYB1, OpWRKY1/2/3, and OpERF1/2/3, have been cloned and analyzed in O. pumila (Kai et al, 2015;Rohani et al, 2016;Udomsom et al, 2016;Shi et al, 2020;Hao et al, 2021;Yang et al, 2021;You et al, 2021). For example, OpWRKY2 acted as a positive regulator of CPT biosynthesis by directly binding and activating the gene OpTDC (Hao et al, 2021).…”