AUTHOR=Chen Ruibing , Chen Xianghui , Zhu Tingting , Liu Jianghua , Xiang Xing , Yu Jian , Tan Hexin , Gao Shouhong , Li Qing , Fang Yichao , Chen Wansheng , Zhang Lei , Huang Baokang TITLE=Integrated Transcript and Metabolite Profiles Reveal That EbCHI Plays an Important Role in Scutellarin Accumulation in Erigeron breviscapus Hairy Roots JOURNAL=Frontiers in Plant Science VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00789 DOI=10.3389/fpls.2018.00789 ISSN=1664-462X ABSTRACT=

Scutellarin, a flavonoid 7-O-glucuronide, is an essential bioactive compound of Erigeron breviscapus (Vaniot) Hand.-Mazz. used for the treatment of cerebrovascular diseases. However, due to overexploitation and overuse, E. breviscapus is facing the problems of extinction and habitat degradation. In this study, a correlation analysis between the transcript and metabolite profiles of methyl jasmonate (MeJA)-treated E. breviscapus at different time points indicated that chalcone isomerase (EbCHI) was the primary contributor to scutellarin accumulation during flavonoid biosynthesis. EbCHI was then further characterized as a chalcone isomerase that efficiently converted chalcone to naringenin in vitro. Optimal parameters derived by comparing different culture conditions were successfully used to establish hairy root cultures of E. breviscapus with a maximum transformation rate of 60% in B5 medium. Furthermore, overexpression of EbCHI significantly enhanced scutellarin accumulation in E. breviscapus hairy roots with a maximum content of 2.21 mg g-1 (dw), 10-fold higher than that of natural roots (0.21 mg g-1 dw). This study sheds new light on a method of effective gene-based metabolic engineering by accurate and appropriate strategies and provides a protocol for hairy root cultures that accumulate high levels of scutellarin, providing a promising prospect for relieving the overexploitation and unavailability of E. breviscapus in the future.