title: Multiple genes of mevalonate and non-mevalonate pathways contribute to high aconites content in an endangered medicinal herb, Aconitum heterophyllum Wall.
abstract: Aconitum heterophyllum Wall, popularly known as Atis or Patis, is an important medicinal herb of North-Western and Eastern Himalayas. No information exists on molecular aspects of aconites biosynthesis, including atisine- the major chemical constituent of A. heterophyllum. Atisine content ranged from 0.14% to 0.37% and total alkaloids (aconites) from 0.20% to 2.49% among 14 accessions of A. heterophyllum. Two accessions contained the highest atisine content with 0.30% and 0.37% as well as the highest alkaloids content with 2.22% and 2.49%, respectively. No atisine was detected in leaves and shoots of A. heterophyllum, thereby, suggesting that the biosynthesis and accumulation of aconite alkaloids occur mainly in roots. Quantitative expression analysis of 15 genes of MVA/MEP pathways in roots versus shoots, differing for atisine content (0-2.2 folds) showed 11-100 folds increase in transcript amounts of 4 genes of MVA pathway; HMGS, HMGR, PMK, IPPI, and 4 genes of MEP pathway; DXPS, ISPD, HDS, GDPS, respectively. The overall expression of 8 genes decreased to 5-12 folds after comparative expression analysis between roots of high (0.37%) versus low (0.14%) atisine content accessions, but their relative transcript amounts remained higher in high content accessions, thereby implying their role in atisine biosynthesis and accumulation. PCA analysis revealed a positive correlation between MVA/MEP pathways genes and alkaloids content. The current study provides first report wherein partial sequences of 15 genes of MVA/MEP pathways have been cloned and studied for their possible role in aconites biosynthesis. The outcome of study has potential applications in the genetic improvement of A. heterophyllum.
authors.affiliation: Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat 173234, Himachal Pradesh, India.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Malhotra
authors.affiliation: Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat 173234, Himachal Pradesh, India.
authors.forename: Varun
authors.initials: V
authors.lastname: Kumar
authors.affiliation: Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat 173234, Himachal Pradesh, India.
authors.forename: Hemant
authors.initials: H
authors.lastname: Sood
authors.affiliation: Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat 173234, Himachal Pradesh, India.
authors.forename: Tiratha Raj
authors.initials: TR
authors.lastname: Singh
authors.affiliation: Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat 173234, Himachal Pradesh, India. Electronic address: rajinder.chauhan@juit.ac.in.
authors.forename: Rajinder Singh
authors.initials: RS
authors.lastname: Chauhan
mesh_terms: D031841:Aconitum / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D000470:Alkaloids / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D007194:India; D008798:Mevalonic Acid / Q000378:metabolism*; D015394:Molecular Structure; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D010946:Plants, Medicinal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction
chemical_list: D000470:Alkaloids; D008798:Mevalonic Acid
keywords: Aconitum heterophyllum; Atisine; Biosynthesis; Expression; MEP; MVA; PCA