Abstract
Glycyrrhizin is a valuable secondary metabolite with high medicinal properties, which is known as the most important compound in the licorice (Glycyrrhiza glabra L.). Considering the problems in growing plants in the field, the use of tissue culture techniques, especially hairy root culture, makes the production of glycyrrhizin simpler and more affordable. The influence of Agrobacterium rhizogenes strains on the efficiency of hairy root induction showed that the highest hairy roots were observed using MSU strain (80%). Also, the effect of explant type (leaf, stem and petiole) and age (two-week-old, three-week-old and four-week-old), light conditions (24 hours of darkness and 16 hours of light-8 hours of darkness) and carbohydrate source (3% glucose and 3% sucrose) showed that the production of hairy roots from this medicinal plant depends on the type and age of explant, light treatment and the composition of the culture medium and the highest hairy roots induction was observed in leaf explant (80%), three-week-old leaf (76.66%) and MS medium containing 3% sucrose (86.66%) and treatment of 24 hours of darkness (86.66%). The amount of glycyrrhizin in hairy root lines treated by 100 µM methyl jasmonate (MJA) after 24 hours increased in the no cutting treated line and decreased in the cutting treated lines compared to the control line. In conclusion, elicitation of G. glabra hairy root culture is a suitable platform for achieving high glycyrrhizin yields.