Induction, Flavonoids Contents, and Bioactivities Analysis of Hairy Roots and True Roots of Diels et Gilg.

The flavonoids in Diels et Gilg () have high medicinal value. However, because of slow growth and harsh ecological environments, is currently an endangered species. In light of this, we present a detailed hairy root induction procedure as a promising alternative to true roots with medicinal value. The percentage of explants induced by () to produce hairy roots out of the total number of explants infected (induction rate 1) was 95.83 ± 7.22%, and the proportion of hairy roots that contained B fragments among all the hairy roots with or without B fragments (positive rate) was 96.57 ± 1.72%. The transformation was further confirmed by the expression of the GUS protein. A high-productive hairy root line was screened for the comparative profiling of six flavonoids with true roots using high-performance liquid chromatography (HPLC). The contents of (+)-catechin, (-)-epicatechin, neochlorogenic acid, luteolin-6-C-glucoside, and orientin were 692.63 ± 127.24, 163.34 ± 31.86, 45.95 ± 3.46, 209.68 ± 6.03, and 56.82 ± 4.75 μg/g dry weight (DW) of 30-day-old hairy roots, respectively, which were higher than those of 3-year-old true roots. Hairy roots have stronger antioxidant activity than true roots. Overall, the hairy roots of could serve as promising alternative sources for the production of flavonoids with medicinal uses.