Medicinal plants are enriched with plenty of pharmaceutically important secondary metabolites, which are specific to different plant parts. Adventitious roots in this regard have their own importance. . Enhancing biomass and secondary metabolite accumulation in the adventitious root culture of Indigofera heterantha is the main objective of the current study. For this purpose, the culture was elicited with Jasmonic acid (JA) with varying concentrations (0-3.0 mg L^-1) for a period of 7 weeks. Varying levels of JA positively influenced fresh as well dry biomass of adventitious root cultures. The biomass accumulation was noted at 7 days interval for a period of 49 days. Among the tested levels, adventitious roots cultured on medium fortified with 1.5 mg L^-1 JA accumulated significantly higher quantity of fresh (24.4 g L^-1) and dry (2.93 g L^-1) biomass than other concentrations. Similarly, by changing the levels of JA in the medium a significant variation in the accumulation of TPC was experienced. The highest TPC (131 µg g^-1DW) was synthesized in adventitious roots when the MS medium was supplemented with JA concentration at the rate of (1.5 mg L^-1). Regarding the total flavonoid contents, adventitious root cultures was observed with maximum TFC (380.00 µg g^-1DW) using the JA at 2 mg L^-1. Furthermore, cultures favoured 1.5 mg L^-1 JA concentrations and resulted in higher (67.78%) antioxidant activities in adventitious root cultures as compared to other JA levels. Hence, it is recommended that adventitious root culture of Indigofera heterantha could be developed potentially with more secondary metabolites in media having optimum amount of JA in culture media.

Keywords: Medicinal plant, Indigofera heterantha, Jasmonic acid, Biomass, Secondary metabolites.