MADS-box gene promotes artemisinin biosynthesis in .

The plant is well known for its production of artemisinin, a sesquiterpene lactone that is an effective antimalarial compound. Although remarkable progress has been made toward understanding artemisinin biosynthesis, the effect of MADS-box family transcription factors on artemisinin biosynthesis is still poorly understood. In this study, we identified a MADS transcription factor, AaSEP4, that was predominantly expressed in trichome. AaSEP4 acts as a nuclear-localized transcriptional activator activating the expression of . Dual-luciferase and Yeast one-hybrid assays revealed that AaSEP4 directly bound to the CArG motif in the promoter region of . Overexpression of in significantly induced the expression of and four artemisinin biosynthesis genes, including , , and . Furthermore, the results of high-performance liquid chromatography (HPLC) showed that the artemisinin content was significantly increased in the overexpressed plants. In addition, RT-qPCR results showed that was induced by methyl jasmonic acid (MeJA) treatment. Taken together, these results explicitly demonstrate that AaSEP4 is a positive regulator of artemisinin biosynthesis, which can be used in the development of high-artemisinin yielding varieties.