Transcriptome analysis provides insights into light condition affect on paclitaxel biosynthesis in yew sapling

Taxus is the rare gymnosperm plants that can solely produce the anticancer drug paclitaxel. Light as the major environmental factor play a crucial role in the growth and development of Taxus plants. However, there is little known about how light conditions affect the growth and metabolic process especially for the paclitaxel biosynthesis. In the present study, we applied three different light conditions to treat the young saplings of T. chinensis and investigated the physiological response and gene expressions. Our results showed that high light lead to oxidation stress and causing photoinhibition and damaged the photosynthetic systems in T. chinensis. In the meanwhile, the paclitaxel content in T. chinensis leaves were significantly decreased following the elevated light intensity. The transcriptomic analysis revealed that a large number of genes involved in paclitaxel biosynthetic and phenylpropanoid metabolic pathway were downregulated under high light condition. In addition, we analyzed the expression patterns of CYP450 gene family under different light conditions and found several genes were high expressed under high light, these genes possibly play an important role in tolerance to the excessive light or heat stress in T. chinensis. Our study promotes to elucidate the molecular mechanism of the effects of environmental factor on the growth and development of T. chinensis and paclitaxel biosynthesis, as well as to facilitate the cultivated Taxus artificially and enhance the production of paclitaxel.