How does UV‐B stress affect secondary metabolites of Scutellaria baicalensis in vitro shoots grown at different 6‐benzyl aminopurine concentrations?

Abstract

Ultraviolet‐B (UV‐B) radiation is one of the abiotic stresses that can significantly affect the secondary metabolite accumulation in in vitro tissue cultures of medicinal plants. The present study investigated the effects of UV‐B radiation on the secondary metabolites and antioxidant activities of Scutellaria baicalensis in vitro shoots grown at different concentrations of 6‐benzyl aminopurine (6‐BA), which is the cytokinin most widely used in plant tissue culture. The UV‐B radiation caused significant increases in lipid peroxidation, total phenolic, and flavonoid contents, and antioxidant activities in the in vitro shoots grown at lower 6‐BA concentrations (0 and 1 mg L−1), while it did not cause any significant changes in those grown at higher 6‐BA concentrations (2 and 3 mg L−1). However, the UV‐B radiation significantly altered the contents of main individual flavonoids at both lower and higher 6‐BA concentrations. Upon UV‐B radiation, aglycones (including baicalein, wogonin, and scutellarein) increased, while glucuronides such as baicalin and wogonoside decreased; this was more evident at higher 6‐BA concentrations. This study demonstrated that the effects of UV‐B radiation on the secondary metabolites of S. baicalensis in vitro shoots highly depended on the 6‐BA concentration in the culture medium.

Melatonin enhances biomass, phenolic accumulation, and bioactivities of rosemary (Rosmarinus officinalis) in vitro shoots under UV‐B stress

“…The malondialdehyde (MDA) content was determined according to Yun et al (2022). Fresh samples (0.5 g) were well grounded in 5 mL of 10% trichloroacetic acid (TCA).…”

Genome-wide identification, stress- and hormone-responsive expression characteristics, and regulatory pattern analysis of Scutellaria baicalensis SbSPLs

“…Second, the accumulation of secondary metabolites in S. baicalensis is associated with abiotic stress. Ultraviolet-B (UV-B) radiation can significantly affect the accumulation of secondary metabolite aglycones (including baicalein, wogonin and scutellarein) in tissue culture and produce oxidative stress (Yun et al 2022 ). Yuan et al found that abnormal temperature (10 °C and 40 °C) reduced the content of flavonoids in S. baicalensis , and high temperature affected the synthesis of two key enzymes, 7-O-glucuronosyltransferase and β-glucuronidase, in the interconversion of baicalin and baicalein (Yuan et al 2012 ).…”