Initiation of callus culture of Juniperus communis L. Horstman

Juniperus communis, belonging to the family of Cupressaceae, is an evergreen tree with needle -like leaves. Juniperus species are known to produce podophyllotoxin, a lignan, which is valuable precursor of anticancer and antiviral medicines (Canel et al. 2000, Eyeberg et al. 2006). Podophyllotoxin itself is too toxic for the therapeutic use but its semisynthetic derivatives are important antitumor medicines used in the treatment of various cancers. Since natural sources of podophyllotoxin become scarce and the demand continuously increases alternative ways to obtain podophyllotoxin are needed (Farkya at al. 2004). Lignans, produced by terrestrial plants, are biosynthetically derived from the phenylpropanoid pathway. However, the biosynthetic formation of podophyllotoxin is not fully known. In order to study biochemical pathways of podophyllotoxin formation we initiated a callus culture of twigs of Juniperus communis L. Horstmann growing in Rombergpark in Dortmund, Germany. To optimize the callus formation we cultivated the twigs on agar plates supplemented with various growth hormones and coal, various temperatures and light cycles. The results showed that callus was formed most effectively when the twigs were cultivated in the media supplemented with 2,4- dichlorophenoxyacetic acid at 25°C in 6000 lux, with light cycle of 16h light and 8 hours dark without activated charcoal. (Canel, C. et al. (2000). Phytochemistry 54, 115–120., Eyberger, A.L. et al. (2006). J. Nat. Prod. 69, 1121–1124., Farkya, S. et al. (2004). Appl. Microbiol. Biotechnol. 65, 504–519.)