Hybrid de novo genome assembly of the Chinese herbal plant danshen (Salvia miltiorrhiza Bunge)

Background: Danshen (Salvia miltiorrhiza Bunge), also known as Chinese red sage, is a member of Lamiaceae family. It is valued in traditional Chinese medicine, primarily for the treatment of cardiovascular and cerebrovascular diseases. Because of its pharmacological potential, ongoing research aims to identify novel bioactive compounds in danshen, and their biosynthetic pathways. To date, only expressed sequence tag (EST) and RNA-seq data for this herbal plant are available to the public. We therefore propose that the construction of a reference genome for danshen will help elucidate the biosynthetic pathways of important secondary metabolites, thereby advancing the investigation of novel drugs from this plant. Findings: We assembled the highly heterozygous danshen genome with the help of 395 × raw read coverage using Illumina technologies and about 10 × raw read coverage by using single molecular sequencing technology. The final draft genome is approximately 641 Mb, with a contig N50 size of 82.8 kb and a scaffold N50 size of 1.2 Mb. Further analyses predicted 34,598 protein-coding genes and 1,644 unique gene families in the danshen genome. Conclusions: The draft danshen genome will provide a valuable resource for the investigation of novel bioactive compounds in this Chinese herb.