title: Comprehensive assessment of the genes involved in withanolide biosynthesis from Withania somnifera: chemotype-specific and elicitor-responsive expression.
abstract: Withania somnifera (L.) Dunal (Family, Solanaceae), is among the most valuable medicinal plants used in Ayurveda owing to its rich reservoir of pharmaceutically active secondary metabolites known as withanolides. Withanolides are C28-steroidal lactones having a triterpenoidal metabolic origin synthesised via mevalonate (MVA) pathway and methyl-D-erythritol-4-phosphate (MEP) pathway involving metabolic intermediacy of 24-methylene (C30-terpenoid) cholesterol. Phytochemical studies suggest differences in the content and/or nature of withanolides in different tissues of different chemotypes. Though development of genomic resources has provided information about putative genes encoding enzymes for biosynthesis of intermediate steps of terpenoid backbone, not much is known about their regulation and response to elicitation. In this study, we generated detailed molecular information about genes catalysing key regulatory steps of withanolide biosynthetic pathway. The full-length sequences of genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis and their paralogs have been characterized for their functional and structural properties as well as phylogeny using bioinformatics approach. The expression analysis suggests that these genes are differentially expressed in different tissues (with maximal expression in young leaf), chemotypes and in response to salicylic acid (SA) and methyl jasmonate (MJ) treatments. Sub-cellular localization studies suggest that both paralogs of sterol ∆-7 reductase (WsDWF5-1 and WsDWF5-2) are localized in the endoplasmic reticulum (ER) thus supporting their indispensible role in withanolide biosynthesis. Comprehensive information developed, in this study, will lead to elucidation of chemotype- as well as tissue-specific withanolide biosynthesis and development of new tools for functional genomics in this important medicinal plant.
authors.affiliation: Council of Scientific and Industrial Research, National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.|Department of Biochemistry, University of Lucknow, Lucknow, 226007, India.
authors.forename: Aditya Vikram
authors.initials: AV
authors.lastname: Agarwal
authors.affiliation: Council of Scientific and Industrial Research, National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.|Botany and Plant Pathology, Oregon State University, 2082-Cordley Hall, Corvallis, OR, 97331, USA.
authors.forename: Parul
authors.initials: P
authors.lastname: Gupta
authors.affiliation: Council of Scientific and Industrial Research, National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.|Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi, 110001, India.
authors.forename: Deeksha
authors.initials: D
authors.lastname: Singh
authors.affiliation: Council of Scientific and Industrial Research, National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.|Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi, 110001, India.
authors.forename: Yogeshwar Vikram
authors.initials: YV
authors.lastname: Dhar
authors.affiliation: Department of Biochemistry, University of Lucknow, Lucknow, 226007, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Chandra
authors.affiliation: Council of Scientific and Industrial Research, National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India. prabodht@nbri.res.in.|Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi, 110001, India. prabodht@nbri.res.in.
authors.forename: Prabodh Kumar
authors.initials: PK
authors.lastname: Trivedi
mesh_terms: D004721:Endoplasmic Reticulum / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D032341:Withania / Q000235:genetics* / Q000378:metabolism; D054358:Withanolides / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D054358:Withanolides; D010088:Oxidoreductases
keywords: Chemotypes; Elicitor response; Sub-cellular localization; Triterpenoid biosynthetic pathway; Withania somnifera; Withanolides