Artemisia annua ZFP8L regulates glandular trichome development

Trichomes are known to be important biofactories that contribute to the production of secondary metabolites, such as terpenoids. C2H2‐zinc finger proteins (C2H2‐ZFPs) are vital transcription factors of plants' trichome development. However, little is known about the function of Artemisia annua C2H2‐ZFPs in trichome development. To explore the roles of this gene family in trichome development, two C2H2‐ZFP transcription factors, named AaZFP8L and AaGIS3, were identified; both are hormonally regulated in A. annua. Overexpression of AaZFP8L in tobacco led to a significant increase in the density and length of glandular trichomes, and improved terpenoid content. In contrast, AaGIS3 was found to positively regulate non‐glandular trichome initiation and elongation, which reduces terpenoid accumulation. In addition, ABA contents significantly increased in AaZFP8L‐overexpressing tobacco lines and AaZFP8L also can directly bind the promoter of the ABA biosynthesis genes. This study lays the foundation for further investigating A. annua C2H2‐ZFPs in trichome development and terpenoid accumulation.