Light emitting diodes (LEDs) have recently been considered an efficient artificial light source in plant factories for enhancing plant growth and nutritional quality. Accordingly, this study aimed to review blue, red, and white LED light sources for efficiency and length of the growing period to produce seedlings of Scutellaria baicalensis with high nutritional value. The roots, stems, and leaves of S. baicalensis seedlings were grown under different LED lights and harvested after two and four weeks, and analyzed using high-performance liquid chromatography and gas chromatography time-of-flight mass spectrometry to identify and quantify primary and secondary metabolites. Roots, particularly in the seedlings treated with white LEDs were determined to contain the greatest concentrations of the representative compounds present in S. baicalensis: baicalin, baicalein, and wogonin, which show highly strong biological properties compared to the other plant organs. A total of 50 metabolites (amino acids, sugars, sugar alcohols, organic acids, phenolic acids, and amines) were detected in the roots, stems, and leaves of S. baicalensis seedlings, and the concentrations of primary and secondary metabolites were generally decreased with the increasing duration of LED illumination. Therefore, this study suggests that white LED light and a 2-week growing period are the most efficient conditions for the production of baicalin, baicalein, and wogonin.

Peanut (Arachis hypogaea) is a crop that can produce resveratrol, a compound with various biological properties, such as those that exert antioxidant, anticancer, and anti-inflammatory effects. In this study, trans-resveratrol was detected in the roots, leaves, and stems of tan and purple seed coat peanuts (Arachis hypogaea) cultivated in a growth chamber. Both cultivars showed higher levels of resveratrol in the roots than the other plant parts. Thus, both cultivars were inoculated with Agrobacterium rhizogenes, in vitro, to promote hairy root development, thereby producing enhanced levels of t-resveratrol. After 1 month of culture, hairy roots from the two cultivars showed higher levels of fresh weight than those of seedling roots. Furthermore, both cultivars contained higher t-resveratrol levels than those of their seedling roots (6.88 ± 0.21 mg/g and 28.07 ± 0.46 mg/g, respectively); however, purple seed coat peanut hairy roots contained higher t-resveratrol levels than those of tan seed coat peanut hairy roots, ranging from 70.16 to 166.76 mg/g and from 46.61 to 54.31 mg/g, respectively. The findings of this study indicate that peanut hairy roots could be a good source for t-resveratrol production due to their rapid growth, high biomass, and substantial amount of resveratrol.