Optimizing biosynthesis: the role of LED light spectra in regulating phenolic and flavonoid accumulation in Matricaria chamomilla L. Root cultures

Matricaria chamomilla L. is a medicinal plant valued for its high content of phenolic and flavonoid compounds. In vitro root cultures represent a promising alternative to field cultivation for controlled and sustainable metabolite production. This study investigated the effects of different LED light spectra (blue, red, white, and darkness) on biomass growth and secondary metabolite accumulation. Blue LED significantly enhanced fresh root biomass (48.7%) and total phenolic content (56.6%), accompanied by the highest antioxidant activity (DPPH assay, p ≤ 0.01). Red light markedly increased total flavonoid content (p ≤ 0.05), whereas darkness promoted the accumulation of gallic acid. LED light spectra act as effective biochemical elicitors for optimizing metabolite production in M. chamomilla root cultures. Blue light is most effective for stimulating phenolic biosynthesis and biomass growth, while red light and darkness favor flavonoid and compound-specific responses. Importantly, LED-driven in vitro systems offer a scalable and environmentally sustainable platform for producing pharmaceutically relevant metabolites.