Strategies to Improve the Production of Forskolin from Hairy Root Cultures of Coleus forskohlii Briq

The aim of this study was to elucidate the effect of elicitors and precursors on the production of forskolin from the hairy root cultures of Coleus forskohlii Briq. Hairy root cultures were established from leaf explants by infecting with Agrobacterium rhizogenes strain A4 on MS basal medium. Suspension cultures of hairy root cultures were initiated in MS medium containing IBA (1.0 mg/L), casein hydrolysate (600 mg/L). We investigated the growth of biomass and forskolin production in suspension cultures of hairy roots. The production of forskolin was parallel to the growth of biomass. The maximum production of forskolin was observed after 5 weeks. With the objective to increase the yield of forskolin, abiotic elicitors such as salicylic acid (100 μM and 500 μM), copper sulphate (100 μM and 500 μM), methyl jasmonate (100 μM and 500 μM) and precursors such as αketoglutaric acid (0.2 mM and 1.0 mM), L-phenylalanine (0.2 mM and 1.0 mM) were added to hairy root cultures on different days of incubation period and evaluated their effects on production of forskolin. Elicitor, methyl jasmonate (500 μM) and the precursor, L-phenylalanine (1 mM) on day14 addition significantly enhanced the production of forskolin over the control hairy root cultures C. forskohlii. Given forskolin’s limited commercial supply, this study provides avenues for improving the production of forskolin in the hairy root culture of C. forskohlii.