Effect of Growth Regulators and Elicitors for The Enhanced Production of Solasodine in Hairy Root Culture of Solanum Melongena (L.)

Solanum melongena (L.), a medicinally important member of family Solanaceae, was evaluated for induction of hairy roots using different strains of the soil borne bacterium Agrobacterium rhizogenes, viz. NCIM 5140, A4, MTCC 532, R 1022 and LBA 9402. In vitro grown cotyledon, cotyledonary node and hypocotyl explants were used for infection. Different concentrations of acetosyringone were incorporated in the medium to investigate their effect on hairy root induction. The transgenicity of putative transgenic roots was confirmed by PCR using rol B and rol C gene specific primers. The media conditions for growth of transformed roots were optimized. Influence of various elicitors, viz. Yeast extract (1 g/l, 2 g/l, 3 g/l), Salicylic acid (50 μM, 100 μM, 200 μM, 500 μM) and Pectin (0.5%, 1%, 1.5%, 2%) on solasodine accumulation in S. melongena (L.) hairy root culture was investigated. Hypocotyl explants infected with NCIM 5140 showed maximum response in terms of hairy root induction. Incorporation of 100 μM acetosyringone in co-cultivation media increased the frequency of hairy root induction within a reduced time period. MS medium supplemented with 3% sucrose and pH 6.5 showed maximum increase in hairy root induction. 1% Pectin was found to be the most efficient elicitor to enhance solasodine production (151.23 μg/g dry weight) by 23-fold over hairy root control (6.5 μg/g dry weight) and by 88-fold over field control (1.71 μg/g dry weight). Thus, solasodine, an important glycoalkaloid, can be enhanced using elicitors in the media and extracted for further pharmacological uses.