ABSTRACT
Object To solve the problem that Taxus chinensis var. mairei (Lemee et L?vl.) Cheng et L. K.Fu grows slowly. Methods The consumption of phosphorus during the cell suspension culture and the effect of fed-batch carbohydrate, nitrogen and phosphorus on cell growth and living-cell activity were assayed. Results The carbohydrate was exhausted in the middle phase of suspension culture, dificiency of carbohydrate led to inhibition of cell growth in the late culture. Conclusion Compared with the control group, the cell growth rate and the cell density in the fed-batch carbohydrate group were increased significantly, and the cell growth rate was up to 83%.
ABSTRACT
Objective To establish and optimize the technology and method of producing large quantity and high-paclitaxe yield callus of 〖WTBX〗Taxus chinensis var. mairei. Methods Wild maternal tree grown in Lingchuan County of Shanxi Province and cultivated tree grown in Xi′an were used as explant source. And the optimum maternal tree for explant cutting, optimum explant type, basic medium, composition and concentration of growth regulators in medium and so on, which were factors of affecting on callus induction, growth and paclitaxe yield, were examined in a series order. Results The juvenile stem segments were the optimum explants because of their earlier and higher rate callus induction than that of other explants. Medium Y5: MS+2,4-D 4.0 mg/L+KIN 1.0 mg/L or medium B5 Ⅲ: B5+2,4-D 3.0 mg/L+KIN 0.1 mg/L+Phe 0.1 mol/L was confirmed optimum callus induction medium in which callus induction rate had reached to 100%. In callus subculture medium, lower concentration of 2,4-D (0.5—3 mg/L) always increased callus growth, but higher concentration of 2,4-D (8 mg/L) reduced callus growth. When 2,4-D concentration was suitable, callus grown on B5 medium displayed lighter browning and faster tissue growth than that on MS medium. Further more, HPLC analysis confirmed that the paclitaxel yield in callus grown on medium MSⅢ was highest and had reached 0.004% of callus dry weight. In a general condition, the level of paclitaxel in calli derived from juvenile stems of wild maternal tree was higher than that in calli initiated from cultivated maternal tree's juvenile stems. Conclusion The optimization sequence of obtaining a large quantity and high-paclitaxe yield callus of T. chinensis var. mairei are dividing juvenile stem segments from wild maternal tree in May and culturing on medium Y5 or B5 Ⅲ for callus induction. After the calli having been subcultured on the same medium for 8—10 generations, one or two generations are recultured on medium MSⅢ. Finally, the calli with more paclitaxel are obtained by extracting paclitaxel out of it.