Involvement of NO in fungal elicitor-induced activation of PAL and stimulation of taxol synthesis in<Emphasis Type="Italic">Taxus chinensis</Emphasis> suspension cells

Elicitor prepared from the cell walls of Peni- cillium citrinum induces multiple responses of Taxus chinensis cells, including nitric oxide (NO) generation, se- quentially followed by the activation of PAL and synthesis of taxol. NO scavenger cPITO and nitric oxide synthase (NOS) inhibitor PBITU prevent the latter two reactions, all of which are triggered in the absence of elicitor by NO donor sodium nitroprusside (SNP). The elicitor-induced NO release of Taxus chinensis suspension cells is strongly inhibited by PBITU. Thesc results demonstrate a causal reationship be- tween NO generation and the latter two reactions of Taxus chinensis cells to the elicitor, and also indicate that NO, pro- duced via NOS in Tasus chinensis cells treated with fungal elicitor might act as an essential signaling molecule for trig- gering the activation of PAL and synthesis of taxol.