Enhancing taxane biosynthesis in cell suspension culture of Taxus chinensis by overexpressing the neutral/alkaline invertase gene

Sucrose metabolism generates material and energy foundations and regulates the biosynthesis of secondary metabolites in plant cell cultures. However, this regulation mechanism is unclear. The neutral/alkaline invertase (NINV) gene is among the key enzymes in sucrose hydrolysis. Thus, the complete open reading frame (ORF) of this gene was obtained from Taxus chinensis cells. This gene was also successfully expressed in Escherichia coli. The expressed protein was verified through the function of sucrose cleavage. Furthermore, the transcriptional levels of the NINV gene can respond to the sucrose concentration changes and relate to taxane biosynthesis in T. chinensis cells. Subsequently, we developed the gene expression vector and introduced it into T. chinensis suspension cells to confirm the role of the NINV gene in taxane biosynthesis. Results indicated that this gene was overexpressed and that it significantly enhanced the expression of the taxadiene synthase (TAS) gene, as well as the biosynthesis of the seven detected individual taxanes. Thus, NINV-mediated sucrose metabolism can promote the biosynthesis of secondary metabolites. This study presents new concepts and approaches to increase the production of secondary metabolites in plant cell cultures.