Importance of glucose-6-phosphate dehydrogenase in taxol biosynthesis in <Emphasis Type="Italic">Taxus chinensis</Emphasis> cultures

The roles of glucose-6-phosphate dehydrogenase (G6PDH) in paclitaxel production were investigated in cell suspension cultures of Taxus chinensis. In the normal cultures, the trend of G6PDH activity was similar to that of cell growth. Addition of glutamate increased G6PDH activity, while dehydroepiandrosterone (DHEA) decreased G6PDH activity. In elicitor-treated cultures, cell growth was depressed, while G6PDH activity and taxol production were enhanced compared with the control. Glutamate recovered the depression of cell growth, and resulted in further increase in G6PDH activity and taxol production. Contrarily, DHEA exacerbated the depression of cell growth, and decreased G6PDH activity and taxol production induced by fungal elicítor. The results indicated that G6PDH played a critic role of taxol production by affecting cell viability.