Effect of biotic and abiotic elicitors on production of betulin and betulinic acid in the hairy root culture of Betula pendula Roth.

Betulin (B) and betulinic acid (BA) are two triterpenoids with a wide range of biological and medicinal activities in different organs of Betula pendula. This research aimed to increase the accumulation of B and BA in the hairy root culture of B. pendula by seven biotic and abiotic elicitors. Hairy root was induced in the stem's inner bark of B. pendula using the C58C1 strain in the WPM (Woody Plant Medium). The effects of different concentrations of elicitors and different time of root harvest in hairy root culture of B. pendula showed that highest level of growth index (GI), B, and BA was acquired in treated hairy roots with chitosan (CTS), chlorocholine chloride (CCC) and chitosan nano-fiber (CTS NF). Highest GI of B. pendula hairy roots was 13 that was obtained in the roots treated with CTS 150 mg l^-1 on the 8th day. The highest content of BA was 1.3 mg g^-1 DW after treatment with 1 mg l^-1CCC on the 4th and 6th days and 200 mg l^-1CTS NF on the 10th day. The highest B content (0.94 mg g^-1DW) was obtained in the treated hairy root by 2 mg l^-1 CCC after 4 and 6 days.