An HD‐ZIP‐MYB complex regulates glandular secretory trichome initiation in <i>Artemisia annua</i>

Plant glandular secretory trichomes (GSTs) produce various specialized metabolites. Increasing GST density represents a strategy to enhance the yield of these chemicals; however, gene regulatory network that controls initiation remains unclear. In previous study Artemisia annua L., we found HD-ZIP IV transcription factor, AaHD1, promotes by directly regulating AaGSW2. Here, identified two AaHD1-interacting factors, namely AaMIXTA-like 2 (AaMYB16) and AaMYB5. Through generation characterization transgenic plants, AaMYB16 is positive regulator initiation, whereas AaMYB5 has opposite effect. Notably, neither them regulates formation independently. Rather, they act competitively, interacting modulating AaHD1 promoter binding activity. Additionally, phytohormone jasmonic acid (JA) was shown be associated with AaHD1-AaMYB16/AaMYB5 through transcriptional regulation via JASMONATE-ZIM DOMAIN (JAZ) protein repressor. These results bring new insights into mechanism complexes, which appear have similar functions in range vascular plant taxa.