Effect Of The Induction Of Taxus Chinensis Var. Mairei Redifferentiation Callus And Buds To Accumulate Of Paclitaxel

Taxus chinensis var. mairei which is national level protection plants and one of theraw materials to produce the anticancer drug taxol is a variant of taxus in China. Inorder to protect natural taxus resources and to use T. chinensis var. mairei callus cultureto produce paclitaxel, we paid close attention to the accumulation distribution regularityof paclitaxel in each morphology part of T. chinensis var. mairei plant, the optimizationof callus culture medium and the dynamics of callus growth, the kinetics of paclitaxelmetabolism, the induce of callus redifferentiation and the tube micro-buds etc.That the accumulation distribution law of paclitaxel in the organs and tissues ofT.chinensis var. mairei plant that was about20years old has been investigatedaccording to the content of paclitaxel by HPLC shows the regular pattern that paclitaxelin the plant is downward and towards rhizosphere accumulation.B₅, MS and improved MS medium were tested respectively supplemented with thedifferent kinds and the diffferent combinations of plant growth regulators to complete acomprehensive comparative research of T. chinensis var. mairei callus induction andculture,then found that the inductive effect difference was not significant with the threebasic culture medium when the other conditions was consistent, but there wassignificant difference on the callus growth state in the culture process,the status of callusgrowth in the modified MS was better than MS and B₅,and plant growth regulators arethe key factors that affect on the induction and growth of T. chinensis var. maireicallus.Improved MS+4.0mg/LNAA+1.3mg/L2,4-D+0.3mg/L KT+0.1%AC is thebest medium for the induction and culture of T. chinensis var. mairei callus in all theapplied medium. The medium supplemented with0.1%AC has a certain inhibitoryaction to the callus to brown, and the paclitaxel content in browning callus is higherthan in no browning callus.Through further improved the combinations of plant growth regulators in improvedMS,and investigated the culture on T.chinensis var. mairei callus induction, the kineticslow of the growth and the paclitaxel metabolism in the callus culture process, theculture on the callus redifferentiation induction etc,then found that the callus growthcurve presented "S" shape, the accumulation of paclitaxel showed a linear increase thatis a process of gradual accumulation, but the accumulated no longer increase as to acertain extent in the callus, and the callus browns constantly along with theaccumulation of paclitaxel in the callus. Modified MS+0.2mg/L IBA+0.05mg/L6-BA+0.3GA3, improved MS+0.2mg/L IBA+0.01mg/L6-BA+0.7GA3, andimproved MS+0.2mg/L IBA+0.1mg/L6-BA+0.5GA3all them benefited theinduction and culture of T.chinensis var. mairei callus, and paclitaxel accumulation wasalso higher, up to0.0378%. the medium supplemented with GA3can shorten the time ofT.chinensis var. mairei callus induction, promote growth, reduce and postpone browning, and increase the accumulation of paclitaxel in the callus.Improved MS+0.05mg/L6-BA+1.0mg/L NAA is better to the induction of T.chinensis var. maireicallus differentiation, and can significantly increase the accumulation of paclitaxel inthe callus with inducing redifferentiation,the paclitaxel content in the redifferentiationcallus can up to0.0599%, compared with undifferentiated callus,it increased0.0221percent.The axillary bud of T.chinensis var. mairei stem segment can be induced andgerminated in Improved MS supplemented with any kind of KT, TIBA, ZT,6-BA, butthe medium supplemented with KT, ZT and6-BA is better than TIBA if the productionof paclitaxel or10-DAB Ⅲ is purpose, and6-BA is the efficientest, and the content ofthe paclitaxel and10-DABⅢ in the induced buds is the highest when the mediumsupplemented with0.01mg/L6-BA and is respectively0.0072%and0.0398%.