Elicitation enhances swerchirin and 1,2,5,6-tetrahydroxyxanthone production in hairy root cultures of Swertia chirayita (Roxb.) H. Karst.

Abstract

Swertia chirayita (Roxb.) H. Karst. is a medicinal herb used in traditional medicines. Scientific authentications of its multiple health benefits against several diseases have incessantly increased its commercial demand in the domestic and international market. As a result, alternative strategies for conventional cultivation/collection are necessary to eliminate the huge gap between demand and supply. Therefore, the goal of this work was to design an efficient hairy root induction protocol and to explore the effects of methyl jasmonate (MJ), sodium nitroprusside (SNP), and salicylic acid (SA) on the improvement of swerchirin (1,8-dihydroxy-3,5-dimethoxyxanthone) and 1,2,5,6-tetrahydroxyxanthone in S. chirayita hairy roots. To produce hairy roots, in vitro-cultured leaf explants were infected Rhizobium rhizogenes LBA 9402 with different cell density, infection time, and acetosyringone concentrations. The highest root induction frequency (87.50 ± 4.94%) and better hairy roots were observed at bacterial cell density (OD600 = 0.8) + 20 min infection time along with 200 µM of acetosyringone. The highest hairy root biomass (222.00 ± 8.33 g/L fresh weight (FW) and 21.64 ± 0.83 g/L dry weight (DW) were observed after 60 days. The highest content of swerchirin (0.710 ± 0.13 mg/g DW, 6th days after elicitation) and 1,2,5,6-tetrahydroxyxanthone (5.501 ± 0.73 mg/g, 6th days after elicitation) was displayed in 100 μM MJ experiment which was 1.80 and 6.0-fold increase than the control. Hence, an efficient developed hairy root protocol of S. chirayita is cost-effective and could be efficiently used for large-scale industrial manufacture of bioactive xanthones.