Triterpenoid saponin biosynthetic pathway profiling and candidate gene mining of the Ilex asprella root using RNA-Seq.
Ilex asprella, which contains abundant α-amyrin type triterpenoid saponins, is an anti-influenza herbal drug widely used in south China. In this work, we first analysed the transcriptome of the I. asprella root using RNA-Seq, which provided a dataset for functional gene mining. mRNA was isolated from the total RNA of the I. asprella root and reverse-transcribed into cDNA. Then, the cDNA library was sequenced using an Illumina HiSeq™ 2000, which generated 55,028,452 clean reads. De novo assembly of these reads generated 51,865 unigenes, in which 39,269 unigenes were annotated (75.71% yield). According to the structures of the triterpenoid saponins of I. asprella, a putative biosynthetic pathway downstream of 2,3-oxidosqualene was proposed and candidate unigenes in the transcriptome data that were potentially involved in the pathway were screened using homology-based BLAST and phylogenetic analysis. Further amplification and functional analysis of these putative unigenes will provide insight into the biosynthesis of Ilex triterpenoid saponins.
Research Center of Chinese Herbal Resource Science and Engineering, Key Laboratory of Chinese Medicinal Resource from Lingnan, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. zheng.x.s1987@163.com.
Xiasheng
X
Zheng
Research Center of Chinese Herbal Resource Science and Engineering, Key Laboratory of Chinese Medicinal Resource from Lingnan, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. zyfxsherry@gzucm.edu.cn.
Hui
H
Xu
Research Center of Chinese Herbal Resource Science and Engineering, Key Laboratory of Chinese Medicinal Resource from Lingnan, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. usermxy@163.com.
Xinye
X
Ma
Research Center of Chinese Herbal Resource Science and Engineering, Key Laboratory of Chinese Medicinal Resource from Lingnan, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. ruotingzhan@vip.163.com.
Ruoting
R
Zhan
Research Center of Chinese Herbal Resource Science and Engineering, Key Laboratory of Chinese Medicinal Resource from Lingnan, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. chenww@gzucm.edu.cn.
Weiwen
W
Chen
D001483:Base Sequence; D053898:Biosynthetic Pathways; D057225:Data Mining; D030541:Databases, Genetic; D004365:Drugs, Chinese Herbal; D004896:Erythritol / Q000031:analogs & derivatives / Q000378:metabolism; D015870:Gene Expression; D020869:Gene Expression Profiling; D017343:Genes, Plant; D030017:Ilex / Q000235:genetics*; D008798:Mevalonic Acid / Q000378:metabolism; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis; D010802:Phylogeny; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000378:metabolism*; D012503:Saponins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017423:Sequence Analysis, RNA; D013185:Squalene / Q000031:analogs & derivatives; D059467:Transcriptome / Q000235:genetics; D014315:Triterpenes / Q000378:metabolism*
C002821:2,3-oxidosqualene; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D012503:Saponins; D014315:Triterpenes; C443879:methyl-D-erythritol 2,4-cyclodiphosphate; D009828:Oleanolic Acid; D013185:Squalene; C036380:beta-amyrin; D004896:Erythritol; D008798:Mevalonic Acid