AUTHOR=Chen Tian-Tian , Yao Xing-Hao , Liu Hang , Li Yong-Peng , Qin Wei , Yan Xin , Wang Xiu-Yun , Peng Bo-Wen , Zhang Yao-Jie , Shao Jin , Hu Xin-Yi , Miao Qing , Fu Xue-Qing , Wang Yu-Liang , Li Ling , Tang Ke-Xuan 

TITLE=MADS-box gene AaSEP4 promotes artemisinin biosynthesis in Artemisia annua

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.982317

DOI=10.3389/fpls.2022.982317

ISSN=1664-462X

ABSTRACT=<p>The plant <italic>Artemisia annua</italic> 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 <italic>AaGSW1 (GLANDULAR TRICHOME-SPECIFIC WRKY1)</italic>. Dual-luciferase and Yeast one-hybrid assays revealed that AaSEP4 directly bound to the CArG motif in the promoter region of <italic>AaGSW1</italic>. Overexpression of <italic>AaSEP4</italic> in <italic>A. annua</italic> significantly induced the expression of <italic>AaGSW1</italic> and four artemisinin biosynthesis genes, including <italic>amorpha-4,11-diene synthase (ADS)</italic>, <italic>cytochrome P450 monooxygenase (CYP71AV1)</italic>, <italic>double-bond reductase 2 (DBR2)</italic> and <italic>aldehyde dehydrogenase 1 (ALDH1)</italic>. Furthermore, the results of high-performance liquid chromatography (HPLC) showed that the artemisinin content was significantly increased in the <italic>AaSEP4-</italic>overexpressed plants. In addition, RT-qPCR results showed that <italic>AaSEP4</italic> 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 <italic>A. annua</italic> varieties.</p>