Comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera

• DOI: 10.1038/srep18611
• Publication Date: 2015-12-21T12:59:09Z
• Authors: Parul Gupta; Ridhi Goel; Aditya Vikram Aga...; Mehar Hasan Asif; Neelam Singh Sangwan; Rajender Singh Sa...; Prabodh Kumar Tri...
• Keywords: Alternative medicine; Withania; Chemotype; Plant Roots; Gene; Article; Therapeutic Potential of Ayurvedic Medicine; Essential oil; Computational biology; 03 medical and health sciences; Gene Expression Regulation, Plant; Health Sciences; Genetics; Pathology; Withanolide; Withanolides; Withania somnifera; Biology; 2. Zero hunger; 0303 health sciences; Plants, Medicinal; Gene Expression Profiling; Herbal Medicine for Neurological Disorders; Botany; Glycosyltransferases; Traditional medicine; Methyltransferases; 15. Life on land; Biosynthetic Pathways; 3. Good health; Plant Leaves; Complementary and alternative medicine; FOS: Biological sciences; Medicine; Gene expression; Transcriptome; Transcription Factors

AbstractWithania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.