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Article|02 Dec 2022|OPEN
SbMYB3 transcription factor promotes root-specific flavone biosynthesis in Scutellaria baicalensis
Yumin Fang1 , Jie Liu1 , Minmin Zheng1,2 , Sanming Zhu3 , Tianlin Pei1,2 , Mengying Cui1 , Lijing Chang2 , Hanwen Xiao1 and Jun Yang1,2 , Cathie Martin4 , Qing Zhao,1,2 ,
1Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
2State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
3National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271000, China
4John Innes Centre, Norwich NR4 7UH, UK
*Corresponding author. E-mail: zhaoqing@cemps.ac.cn

Horticulture Research 10,
Article number: uhac266 (2023)
doi: https://doi.org/10.1093/hr/uhac266
Views: 307

Received: 19 Sep 2022
Accepted: 21 Nov 2022
Published online: 02 Dec 2022

Abstract

Scutellaria baicalensis Georgi produces abundant root-specific flavones (RSFs), which provide various benefits to human health. We have elucidated the complete biosynthetic pathways of baicalein and wogonin. However, the transcriptional regulation of flavone biosynthesis in S. baicalensis remains unclear. We show that the SbMYB3 transcription factor functions as a transcriptional activator involved in the biosynthesis of RSFs in S. baicalensis. Yeast one-hybrid and transcriptional activation assays showed that SbMYB3 binds to the promoter of flavone synthase II-2 (SbFNSII-2) and enhances its transcription. In S. baicalensis hairy roots, RNAi of SbMYB3 reduced the accumulation of baicalin and wogonoside, and SbMYB3 knockout decreased the biosynthesis of baicalein, baicalin, wogonin, and wogonoside, whereas SbMYB3 overexpression enhanced the contents of baicalein, baicalin, wogonin, and wogonoside. Transcript profiling by qRT–PCR demonstrated that SbMYB3 activates SbFNSII-2 expression directly, thus leading to more abundant accumulation of RSFs. This study provides a potential target for metabolic engineering of RSFs.