Effect of pH on callus growth, PAL activity and paclitaxel content of plants of Taxus L / 中草药

Object To study the effect of pH on callus tissue growth and paclitaxel content of Taxus cuspidata Sieb. et Zucc. and Taxus chinensis var. mairei (Lemee et Le ′vl.) Cheng et L. K. Fu Methods The callus tissues were cultured on B5 medium with defferent pH values, and the growth rate, PAL activity and paclitaxel content were determined. Results Different callus tissues of taxus need different optimum pH values. The pH values, which could promote callus growth significantly, were all inhabitory to PAL activity and accumulation of paxlitaxel. Conclusion pH had great influences on the growth of the callus and the level of secondary metabolism, thereby the synthesis and accumulation of paclitaxel were affected.