Conventional fluorescent lamps that are used in tissue culture are costly light sources, exhibiting excessive wavelength emission-bandwidth that must be replaced by alternative, less costly, and much lower power-consuming energy sources. The use of Light-Emitting Diodes (LEDs) is the best option due to their potential role as elicitors of secondary metabolite production in many plant models. Gynura procumbens (G. procumbens) is widely used for treating various diseases. Here, leaf explants were cultivated in MS medium that was supplemented with 0.5 mg/L of naphthaleneacetic acid (NAA) and 2.0 mg/L of benzylaminopurine (BAP) for 30 days under white, blue, and red LEDs. Secondary metabolites were analyzed by High Performance Liquid Chromatography (HPLC) and Liquid Chromatography-Mass Spectrometry (LC-MS). Blue LEDs elicited the highest antioxidant activity, total flavonoid, and phenolic content. Furthermore, the content of cyanidin-monoglucosides significantly increased under blue light.
Keywords: Gynura procumbens; HPLC; LC-MS; LEDs; callus; cyanidin-monoglucosides; elicitor.