title: Deep sequencing and transcriptome analyses to identify genes involved in secoiridoid biosynthesis in the Tibetan medicinal plant Swertia mussotii.
abstract: Swertia mussotii Franch. is an important traditional Tibetan medicinal plant with pharmacological properties effective in the treatment of various ailments including hepatitis. Secoiridoids are the major bioactive compounds in S. mussotii. To better understand the secoiridoid biosynthesis pathway, we generated transcriptome sequences from the root, leaf, stem, and flower tissues, and performed de novo sequence assembly, yielding 98,613 unique transcripts with an N50 of 1,085 bp. Putative functions could be assigned to 35,029 transcripts (35.52%) based on BLAST searches against annotation databases including GO and KEGG. The expression profiles of 39 candidate transcripts encoding the key enzymes for secoiridoid biosynthesis were examined in different S. mussotii tissues, validated by qRT-PCR, and compared with the homologous genes from S. japonica, a species in the same family, unveiling the gene expression, regulation, and conservation of the pathway. The examination of the accumulated levels of three bioactive compounds, sweroside, swertiamarin, and gentiopicroside, revealed their considerable variations in different tissues, with no significant correlation with the expression profiles of key genes in the pathway, suggesting complex biological behaviours in the coordination of metabolite biosynthesis and accumulation. The genomic dataset and analyses presented here lay the foundation for further research on this important medicinal plant.
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.|National Resource Center for Chinese Materia Medica, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.affiliation: USDA-ARS, Western Regional Research Center, Albany, CA 94710, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Fengxian
authors.initials: F
authors.lastname: Guo
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhan
authors.affiliation: USDA-ARS, Western Regional Research Center, Albany, CA 94710, USA.
authors.forename: Toni
authors.initials: T
authors.lastname: Mohr
authors.affiliation: USDA-ARS, Western Regional Research Center, Albany, CA 94710, USA.
authors.forename: Prisca
authors.initials: P
authors.lastname: Cheng
authors.affiliation: USDA-ARS, Western Regional Research Center, Albany, CA 94710, USA.|Department of Plant Science, University of California Davis, Davis, CA 95616, USA.
authors.forename: Naxin
authors.initials: N
authors.lastname: Huo
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Ronghui
authors.initials: R
authors.lastname: Gu
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Danning
authors.initials: D
authors.lastname: Pei
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Jiaqing
authors.initials: J
authors.lastname: Sun
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Li
authors.initials: L
authors.lastname: Tang
authors.affiliation: College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Long
authors.affiliation: National Resource Center for Chinese Materia Medica, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
authors.forename: Luqi
authors.initials: L
authors.lastname: Huang
authors.affiliation: USDA-ARS, Western Regional Research Center, Albany, CA 94710, USA.
authors.forename: Yong Q
authors.initials: YQ
authors.lastname: Gu
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D039823:Iridoids / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D010946:Plants, Medicinal / Q000235:genetics* / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D029967:Swertia / Q000235:genetics* / Q000378:metabolism*
chemical_list: D039823:Iridoids