Optimization of hairy root production in Calendula officinalis for production of oleanolic acid

Calendula officinalis is a medicinal plant and widely used for its anti-inflammatory, antibacterial, antifungal and etc properties. Oleanolic acid is an important bioactive compounds which found in C.officinalis. Hairy root cultures are characterized by high growth rate and ability to synthesize secondary metabolites. Some factors are effective on the production of hairy roots. So this experiment was performed to select the best strain of Agrobacterium rhizogenes , culture medium and light condition for production of hairy roots. Highest (43/4%) and the lowest (13/69%) of hairy root production were obtained by MSU and 2656 strains respectively. The Average production of hairy roots in ½B5 culture medium, 35/84% and in ½ MS culture medium was 25/67%. So it seems that the ½ B5 medium is better culture medium. There was no significant difference between light and dark condition for production of hairy roots. The branches (6-7cm) from A1 clone of hairy roots were cultured in ½ B5, ¼ B5, ½ MS and ¼ MS culture media, in both liquid and solid media, and the branches were treated by three concentrations of auxin (IAA) (0, 5.0 and 1 mg/l). After two months, Hairy roots have highest growth in the ½ B5 culture medium with 1mg/l of IAA. The effect of three levels of methyl jasmonate elicitor (0, 500 and 100mM) on amount of oleanolic acid was investigated in normal roots and hairy roots and determined by HPLC. Methyl jasmonate at 500mM, increased oleanolic acid production but at 100mM concentration, this compound was reduced.