Transcriptomic analysis reveals the parallel transcriptional regulation of UV-B-induced artemisinin and flavonoid accumulation in Artemisia annua L

• Published in: Plant physiology and biochemistry 2021-06, Vol.163, p.189-200
• Main Authors: Li, Yongpeng, Qin, Wei, Fu, Xueqing, Zhang, Yaojie, Hassani, Danial, Kayani, Sadaf-Ilyas, Xie, Lihui, Liu, Hang, Chen, Tiantian, Yan, Xin, Peng, Bowen, Wu-Zhang, Kuanyu, Wang, Chen, Sun, Xiaofen, Li, Ling, Tang, Kexuan
• Format: Article
• Language: English
• Subjects: Artemisia annua; Artemisia annua - genetics; Artemisia annua - metabolism; Artemisinin; Artemisinins - metabolism; Flavonoid accumulation; Flavonoids; Gene Expression Regulation, Plant; Transcription regulation; Transcriptome; Ultraviolet Rays; UV-B radiation
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2021.03.052

UV-B radiation is a pivotal photomorphogenic signal and positively regulates plant growth and metabolite biosynthesis. In order to elucidate the transcriptional regulation mechanism underlying UV-B-induced artemisinin and flavonoid biosynthesis in Artemisia annua, the transcriptional responses of A. annua L. leaves to UV-B radiation were analyzed using the Illumina transcriptome sequencing. A total of 10705 differentially expressed genes (DEGs) including 533 transcription factors (TFs), were identified. Based on the expression trends of the differentially expressed TFs as well as artemisinin and flavonoid biosynthesis genes, we speculated that TFs belonging to 6 clusters were most likely to be involved in the regulation of artemisinin and/or flavonoid biosynthesis. The regulatory relationship between TFs and artemisinin/flavonoid biosynthetic genes was further studied. Dual-LUC assays results showed that AaMYB6 is a positive regulator of AaLDOX which belongs to flavonoid biosynthesis pathway. In addition, we identified an R2R3 MYB TF, AaMYB4 which potentially mediated both artemisinin and flavonoid biosynthesis pathways by activating the expression of AaADS and AaDBR2 in artemisinin biosynthesis pathway and AaUFGT in flavonoid biosynthesis pathway. Overall, our findings would provide an insight into the elucidation of the parallel transcriptional regulation of artemisinin and flavonoid biosynthesis in A. annua L. under UV-B radiation. •UV-B radiation boosted the expression of various structural genes related to artemisinin and flavonoid biosynthesis pathways.•UV-B promoted both artemisinin and flavonoid accumulation.•AaMYB6 could positively regulate UV-B induced flavonoid biosynthesis by activating the expression of AaLDOX in A. annua.•AaMYB4 triggers the promoters of ADS and DBR2 in artemisinin biosynthesis pathway and UFGT in flavonoid biosynthesis pathway.