Jasmonic acid responsive AaJRM1 transcription factor positively regulates the biosynthesis of anti-malarial drug artemisinin in Artemisia annua

The phytohormone jasmonic acid (JA) and environmental factor light have the ability to synergistically affect the biosynthesis of anti-malarial drug artemisinin in traditional Chinese medicinal plant Artemisia annua. Previous studies have screened a JA-responsive R2R3-MYB transcription factor, AaJRM1, as a candidate gene for regulating artemisinin biosynthesis by transcriptome sequencing after JA treatment in light signals. However, the function and regulatory mechanism of AaJRM1 on artemisinin biosynthesis have not been illus. In this study, transcriptional level analysis showed that the expression of AaJRM1 was the most highly expressed in trichomes and rapidly responded to JA treatment, which was similar to the expression profiles of the specific genes belonging to artemisinin biosynthesis. The regulatory potential of artemisinin biosynthesis using transgenic A. annua plants indicated that overexpression and suppression of AaJRM1 increased and decreased the accumulation of artemisinin, respectively. The expression analysis revealed that the transcriptions of four core biosynthetic genes were significantly increased in AaJRM1-OE plants and obviously declined in AaJRM1-EAR transgenic lines compared with the wild-type control. Dual-Luciferase assays demonstrated that AaJRM1 significantly activated the transcription of artemisinin biosynthetic genes. Therefore, this study elucidated the molecular mechanism of JA-responsive AaJRM1 transcription factor regulating artemisinin biosynthesis, and provided a theoretical basis for the use of biotechnology to cultivate new germplasm with high artemisinin content.