Hairy roots induction and effect of methyl jasmonate and chitosan application on physalin B content in Physalis alkekengi L.

Physalins are the most important secondary metabolites extracted from Physalis spp. medicinal plant that have a high potential to stop the growth of cancer cells. In this research, induction of hairy roots by two strains of Agrobacterium rhizogenes (ATCC15834 and A4) in different explants consist of leaves, internodes, hypocotyl, and roots of P. alkekengi in 6 media culture (1/2MS, MS, and B5 each of them containing two levels of 1.5 and 3% sucrose) were studied. The highest hairy roots numbers were inducted by ATCC15834 strain in leaf explants on B5 medium containing 1.5% sucrose. The highest fresh and dry weights of hairy roots were obtained in B5 culture medium containing 3% sucrose. In addition, the effects of chitosan elicitor at concentrations of 0, 50, 100, and 150 mg L.-1 and methyl jasmonate at concentrations of 0, 20, 40, and 60 mg L.-1 on physalin B content and hairy root growth were evaluated. Chitosan treatment had no significant effect on the production of physalin B, but its effect on the growth of hairy roots was significant at 50 mg L.-1 concentration. Methyl jasmonate at a concentration of 60 mg L.-1 resulted in a significant increase of 3.026 times in the production of physalin B compared to the control, however, none of the three concentrations of methyl jasmonate had a significant effect on hairy roots growth. This study is the first report on the effect of these elicitors on the secondary metabolite physalin B.