Transcriptome Assembly and Systematic Identification of Novel Cytochrome P450s in Taxus chinensis

Abstract

Taxus spp. is a highly valuable medicinal plant with multiple pharmacological effects on various cancers. Cytochrome P450s (CYP450s) play important roles in the biosynthesis of active compounds in Taxus spp., such as the famous diterpenoid, Taxol. However, some specific CYP450 enzymes involved in the biosynthesis of Taxol remain unknown, and the systematic identification of CYP450s in Taxus has not been reported. In this study, 118 full-length and 175 partial CYP450 genes were identified in Taxus chinensis transcriptomes. The 118 full-length genes were divided into 8 clans and 29 families. The CYP71 clan included all A-type genes (52) belonging to 11 families. The other seven clans possessed 18 families containing 66 non-A-type genes. Two new gymnosperm-specific families were discovered, and were named CYP864 and CYP947 respectively. Protein sequence alignments revealed that all of the T. chinensis CYP450s hold distinct conserved domains. The expression patterns of all 118 CYP450 genes during the long-time subculture and MeJA elicitation were analyzed. Additionally, the expression levels of 15 novel CYP725 genes in different Taxus species were explored. Considering all the evidence, 6 CYP725s were identified to be candidates for Taxol biosynthesis. The cis-regulatory elements involved in the transcriptional regulation were also identified in the promoter regions of CYP725s. This study presents a comprehensive overview of the CYP450 gene family in T. chinensis and can provide important insights into the functional gene studies of Taxol biosynthesis.

Comparative functional genomics analysis of cytochrome P450 gene superfamily in wheat and maize

“…And with more and more genome sequences available, an ever-growing number of CYP450 sequences were identified. To date, the genes have been identified in many plant species at a whole-genome scale, such as Arabidopsis [30], Oryza sativa [31], Nelumbo nucifera [32], Glycine max [33] and Taxus chinensis [34], whereas no systematical investigation of CYP450s has been performed in wheat and maize. In the present study, we carried out the first comprehensive analysis of wheat and maize genomes for CYP450 superfamily.…”

Identification and analysis of CYP450 supergene family members from the transcriptome of Aralia elata (Miq.) Seem reveal candidate genes for triterpenoid saponins biosynthesis

“…The advent of next-generation sequencing technologies such as RNA-Seq has allowed for the more rapid and cost-effective identification of CYP450s [6]. More recent transcriptomic studies have, for example, detected 116 full-length and 135 partial-length CYP450s in Salvia miltiorrhiza [7], with similar work being performed in Lonicera japonica [8] and Taxus chinensis [9]. More recently, a genome-wide study of rice identified 355 CYP450s that clustered into 10 clans including 45 families [10].…”

Comparative transcriptome analysis of root, stem, and leaf tissues of Entada phaseoloides reveals potential genes involved in triterpenoid saponin biosynthesis

“…Recently, transcriptome assay with next-generation sequencing has been extensively used to explore the novel genes underlying active-ingredient biosynthesis pathways in medicinal plants. Some include the excavation of genes encoding enzymes that catalyze distinct steps related to the biosynthetic pathway of ginsenosides in Panax ginseng [13], triterpenoid saponin biosynthesis in Bacopa monnieri [14], artemisinin in Artemisia annua [15,16], avonoid biosynthesis in sa ower [17], glycyrrhizin in Glycyrrhiza uralensis [18], rubber in Parthenium argentatum [19], cardiac glycoside in Calotropis procera [20], terpenoid in Cinnamomum camphora [21], cannabinoids in Cannabis sativa [22], withanolide in Withania somnifera [23], picrosides in Picrorhiza kurrooa [24], paclitaxel in Taxus chinensis [25] and steroidal saponins in Asparagus racemosus [26].…”