Metabolic Characteristics of Hairy Root Clones of Scutellaria pycnoclada and Scutellaria baicalensis

Abstract

Scutellaria baicalensis is the most studied species of the genus, while Scutellaria pycnoclada is a poorly studied endemic species. Ten lines of the hairy roots of S. pycnoclada were obtained using Agrobacterium rhizogenes A4. The hairy root cultures of S. pycnoclada and the previously obtained roots of S. baicalensis were cultured on liquid and agar Gamborg media. A total of 14 flavonoids were detected via HPLC MS/MS in S. pycnoclada, and 17 were detected in S. baicalensis. Among them were flavones characteristic of both the roots and the aboveground parts of the plants. S. pycnoclada had a lower diversity of methylated flavones than S. baicalensis. Moreover, tenaxin I was absent in all S. pycnoclada lines on agar medium. HPLC analysis revealed that the flavone content in the different hairy root lines was 1.4–12.7 times higher on liquid medium than on agar medium. S. baicalensis and S. pycnoclada differed significantly in the ratio of the main flavones. In S. baicalensis, baicalin (7.83 mg/g DW) and wogonoside (6.29 mg/g DW) dominated when cultured on liquid medium, and wogonin (2.08 mg/g DW) dominated when cultured on solid medium. In S. pycnoclada, baicalin predominated (52–88% of the total content). S. pycnoclada is assumed to have a different set of O-methyltransferases and less biosynthetic enzyme activity than S. baicalensis.