Production Enhancement of Medicinally Active Coumarin and Phenolic Compounds in Hairy Root Cultures of Pelargonium sidoides: The Effect of Elicitation and Sucrose

African geranium (Pelargonium sidoides DC., Geraniaceae) is a herbaceous perennial plant with well-known medicinal properties. In the present study, the effect of elicitation by methyl jasmonate (MeJ) (25, 50, and 100 mu M) and sucrose (15 and 30 g/L) on the fresh weight (FW), dry weight (DW) and the production of pharmaceutically active coumarin (umckalin) and phenolics (gallic, vanillic, and p-coumaric acids) in P. sidoides hairy root cultures was investigated. Hairy roots were induced from the leaves of in vitro sterile P. sidoides seedlings inoculated with Agrobacterium rhizogenes strains (LBA-9402, C58C1) and Agrobacterium tumefaciens C58C1 (pRiA4). Among the fifteen evaluated hairy root lines (HRLs), HRL4 showed the highest accumulation of biomass (9.6 g FW and 0.56 DW) and was selected for elicitation and sucrose management for 50 days in a shaking system. The treated HRs, developed in Murashige and Skoog liquid media, demonstrated the highest FW (32.68 g) and DW (1.1 g) 50 days after elicitation with 100 mu M of MeJ. However, a 1.4-fold enhancement of gallic and vanillic acids was achieved with 50 and 25 mu M of MeJ, respectively, in HRs under control conditions. The highest accumulation of umckalin (1.61-fold increase compared to the control) was obtained with 100 mu M of MeJ. These findings can be useful to develop commercial production of umckalin and phenolics in P. sidoides HR cultures in scaled-up systems and bioreactors.