Overexpression of AaWRKY1 Leads to an Enhanced Content of Artemisinin in Artemisia annua

Artemisinin is an effective component of drugs against malaria. The regulation of artemisinin biosynthesis is at the forefront of artemisinin research. Previous studies showed that AaWRKY1 can regulate the expression ofADS, which is the first key enzyme in artemisinin biosynthetic pathway. In this study,AaWRKY1was cloned, and it activated ADSpro and CYPpro in tobacco using dual-LUC assay. To further study the function of AaWRKY1, pCAMBIA2300-AaWRKY1 construct under 35S promoter was generated. Transgenic plants containingAaWRKY1were obtained, and four independent lines with high expression ofAaWRKY1were analyzed. The expression ofADSandCYP, the key enzymes in artemisinin biosynthetic pathway, was dramatically increased inAaWRKY1-overexpressingA. annuaplants. Furthermore, the artemisinin yield increased significantly inAaWRKY1-overexpressingA. annuaplants. These results showed that AaWRKY1 increased the content of artemisinin by regulating the expression of bothADSandCYP. It provides a new insight into the mechanism of regulation on artemisinin biosynthesis via transcription factors in the future.