Increase of Taxol Production in Taxus globosa Shoot Callus by Chlorocho- line Chloride

Calluses from seasonal mature shoots of Taxus globosa Schltdl. were subcultured in new medium containing 1 mg l -1 NAA, 0.5 mg l -1 2, 4-D, 0.025 mg l -1 BA. Calluses growing for 30 and 40 days in a medium added with 0.1-5.0 mg l -1 of chlorocholine chloride (CCC) were harvested for determination of taxol, phenolic compounds, and for polyphenol oxidase (PPO) activity. The results showed that by increasing the CCC concentration, callus growth was decreased, phenolic level was raised up, but taxol content and PPO activity changed differently. The highest taxol production (0.0269 mg g -1 dry weight callus) and PPO activity (4.53 U g -1 fresh weight callus) were achieved at day 40 with a medium containing 0.5 mg l -1 CCC. Possible reason of higher taxol level stimulated by CCC is discussed in the text.