Spectral light treatment and exogenous feeding of precursors enhanced the picrosides content in dedifferentiated cell culture of Picrorhiza kurroa

The present investigation evaluates the impact of the light spectrum (red and blue) and precursors treatment on picrosides (P-I, P-II, P-III) and pathway precursors metabolites enrichment in the cell culture of Picrorhiza kurroa. Exogenously, vanillic acid (VA), phenylalanine (PAL), and trans-cinnamic acid (TCNA) precursors were used in 50–150 mg/L concentrations to leaf and rhizome cell suspension of P. kurroa. The maximum content of P-I (0.872 and 0.894 mg/g DW), P-II (0.892 and 0.837 mg/g DW), P-III (0.286 and 0.288 mg/g DW) were quantified in leaf and rhizome cell suspension cultures under red light treatment. The maximum content (mg/g DW) of picrosides (P-I; 9.881, P-II; 3.939, and P-III; 0.884), VA (0.236), and caffeic acid (CFA; 0.20) were quantified in 150 mg/L VA in leaf suspension culture. The maximum content of catalpol (CTP; 5.845 mg/g DW) was quantified in PAL 100 mg/L, while cinnamic acid (CAN; 0.176, 0.179, 0.162 mg/g DW) was quantified in 150 mg/L of VA, PAL, and TCNA. However, in rhizome suspension culture, the maximum content (mg/g DW) of P-I (7.881), P-III (0.964), and VA (0.324) were found in VA 150 mg/L. The results concluded that VA (100–150 mg/L) is most suitable for picrosides enrichment in the cell culture of P. kurroa. The study confirms that red light and vanillic acid (VA) treatment significantly enhanced the picrosides and precursor metabolite in cell cultures. By utilizing the current approach coupled with elicitor treatments and scale-up studies at bioreactor level could facilitate the large-scale production of picrosides.