Role Of ERK In The Signaling Of Ce～(4+)-Induced Secondary Metabolism Of T. Cuspidata Cells

In order to well-understand how do secondary signals work on enzymes and genes, which are related to the secondary metabolism during the induction of Taxus cuspidate by Ce⁴⁺, we conducted a systemic study on the phosphorylation of ERK induced by Ce⁴⁺, and investigated the relationship between the activity of ERK and the expression of txs and the activities of PAL and LOX. From the work below, we gained some valuable results.(1) That Ce⁴⁺ could effectively induce the phosphorylation of ERK from the result of Western Bloting, and the activity of ERK was depending on the dose of Ce⁴⁺.(2) The result of Western Bloting also showed that the activity of ERK decreased when PD98059, the special inhibitor of MAPKK, was applied to the inducing system. And the level of phosphorylation was 89% to the control and 46% to inducing group, when the concentration of PD98059 reached 200uM.(3) The expression of txs was analyzed using semi-quantification RT-PCR, and the result showed that the transcriptional level of txs was quite associated with the activity of ERK.(4) Enzyme study indicated that the activities of PAL and LOX were also related to the activity of ERK.Conclusion: the phosphorylation of ERK would play an important role in linking the secondary signals to the secondary metabolism of the T. cuspidate cells.