Taxol is currently a valuable anticancer drug; however, the accumulated mixture of taxoids can vary greatly among Taxus species. So far, there is very little genomic information for the genus Taxus, except for Taxus baccata. Transcriptome analysis is a powerful approach to explore the different regulatory mechanisms underlying the taxoid biosynthesis pathway in Taxus species. First, we quantified the variation in the taxoid contents between Taxus media and Taxus mairei. The contents of paclitaxel and 10-deacetylpaclitaxel in T. media are higher than that in T. mairei. Then, the transcriptome profiles of T. media and T. mairei were analyzed to investigate the altered expressions. A total of 20,704 significantly differentially expressed genes (DEGs), including 9865 unigenes predominantly expressed in T. media and 10,839 unigenes predominantly expressed in T. mairei, were identified. In total, 120 jasmonic acid-related DEGs were analyzed, suggesting variations in ‘response to JA stimulus’ and ‘JA biosynthetic process’ pathways between T. media and T. mairei. Furthermore, a number of genes related to the precursor supply, taxane skeleton formation and hydroxylation, and C13-side chain assembly were also identified. The differential expression of the candidate genes involved in taxoid biosynthetic pathways may explain the variation in the taxoid contents between T. media and T. mairei.
Taxus species are well-known for paclitaxel, which exhibits antitumor activities and is used for treating various cancers. Although most Taxus species are widespread in many areas, few studies have characterized the variation in metabolism among different Taxus species. Using an integrated approach involving ‘tandem mass tag’ labeling and liquid chromatography–tandem mass spectrometry (HPLC–MS), proteomes of T. media and T. mairei were investigated and 4078 proteins were quantified. Screening and classification of differentially expressed proteins revealed many metabolism-associated proteins. In detail, four enzymes involved in the flavonoid biosynthesis pathway were predominantly expressed in T. mairei. Four enzymes associated with supplying precursors for paclitaxel biosynthesis and three cytochrome P450 taxoid oxygenases were preferentially expressed in T. media compared with T. mairei. Furthermore, variations in taxoid contents between T. media and T. mairei were determined using HPLC–MS analysis. Variations in flavonoid contents between T. media and T. mairei were determined by HPLC analysis. A number of differentially expressed proteins may provide an explanation for the variation in metabolisms of different Taxus species.
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