Transcriptome analysis of a tropical medicinal plant, Pistacia weinmannifolia

Pistacia weinmannifolia has long been used as an herbal medicine for treating various illnesses. The genomic information of P. weinmannifolia will help elucidate the chemical constituents that exert medicinal effects; however, genomic studies have rarely been performed. Therefore, we conducted a transcriptome analysis of P. weinmannifolia using the Illumina RNA sequencing system. We obtained a total of 18 million high-quality paired-end reads with 2,230 Mbp. De novo assembly of high-quality reads generated a total of 18,956 non-redundant contigs with an average length of 901 bp, of which 18,296 contigs (96.5%) were annotated. The total length of all unigenes was 17,080,830 bp, and the GC content and N50 were 43.2% and 1,137 bp, respectively. Annotation using The Kyoto Encyclopedia of Genes and Genomes (KEGG) assigned a total of 5,095 unigenes (26.9%), of which 3,166 were mapped to 410 different KEGG meta-bolic pathways. A comparison of unigenes between P. weinmannifolia and Pistacia chinensis showed that 8,825 unigenes were highly similar to each other. Simple sequence repeats were mined, and valuable data for further comparative and functional genomic studies were obtained to uncover the mechanisms underlying the medicinal properties of P. weinmannifolia as an important medicinal plant. Several genes of P.weinmannifolia involved in the biosynthesis of eugenol and isoeugenol were also identified in this study.