De novo transcriptome assembly of Conium maculatum L. to identify candidate genes for coniine biosynthesis

Poison hemlock (Conium maculatum L.) is a notorious weed containing the potent alkaloid coniine. Only some of the enzymes in the coniine biosynthesis have so far been characterized. Here, we utilize the next-generation RNA sequencing approach to report the first-ever transcriptome sequencing of five organs of poison hemlock: developing fruit, flower, root, leaf, and stem. Using a de novo assembly approach, we derived a transcriptome assembly containing 123,240 transcripts. The assembly is deemed high quality, representing over 88% of the near-universal ortholog genes of the Eudicots clade. Nearly 80% of the transcripts were functionally annotated using a combination of three approaches. The current study focuses on describing the coniine pathway by identifying in silico transcript candidates for polyketide reductase, l-alanine:5-keto-octanal aminotransferase, gamma-coniceine reductase, and S-adenosyl-l-methionine:coniine methyltransferase. In vitro testing will be needed to confirm the assigned functions of the selected candidates.

Automated summary

In this study, the first-ever transcriptome sequencing of poison hemlock was conducted using next-generation RNA sequencing approach, resulting in a high-quality transcriptome assembly. The focus of the study was on describing the coniine pathway and identifying several enzymes related to coniine biosynthesis. Further in vitro testing will be necessary to confirm the functions of the selected candidates.