title: Physical Mapping of Amplified Copies of the 5-Enolpyruvylshikimate-3-Phosphate Synthase Gene in Glyphosate-Resistant Amaranthus tuberculatus.
abstract: Recent and rapid evolution of resistance to glyphosate, the most widely used herbicides, in several weed species, including common waterhemp (Amaranthus tuberculatus), poses a serious threat to sustained crop production. We report that glyphosate resistance in A tuberculatus was due to amplification of the 5-enolpyruvylshikimate-3-P synthase (EPSPS) gene, which encodes the molecular target of glyphosate. There was a positive correlation between EPSPS gene copies and its transcript expression. We analyzed the distribution of EPSPS copies in the genome of A tuberculatus using fluorescence in situ hybridization on mitotic metaphase chromosomes and interphase nuclei. Fluorescence in situ hybridization analysis mapped the EPSPS gene to pericentromeric regions of two homologous chromosomes in glyphosate sensitive A tuberculatus In glyphosate-resistant plants, a cluster of EPSPS genes on the pericentromeric region on one pair of homologous chromosomes was detected. Intriguingly, two highly glyphosate-resistant plants harbored an additional chromosome with several EPSPS copies besides the native chromosome pair with EPSPS copies. These results suggest that the initial event of EPSPS gene duplication may have occurred because of unequal recombination mediated by repetitive DNA. Subsequently, gene amplification may have resulted via several other mechanisms, such as chromosomal rearrangements, deletion/insertion, transposon-mediated dispersion, or possibly by interspecific hybridization. This report illustrates the physical mapping of amplified EPSPS copies in A tuberculatus.
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Andrew
authors.initials: A
authors.lastname: Dillon
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Varanasi
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Tatiana V
authors.identifier: 0000-0003-2209-1911
authors.initials: TV
authors.lastname: Danilova
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Dal-Hoe
authors.initials: DH
authors.lastname: Koo
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Sridevi
authors.initials: S
authors.lastname: Nakka
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Dallas E
authors.initials: DE
authors.lastname: Peterson
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Patrick J
authors.identifier: 0000-0003-0666-4564
authors.initials: PJ
authors.lastname: Tranel
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Bernd
authors.initials: B
authors.lastname: Friebe
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.).|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.).
authors.forename: Bikram S
authors.identifier: 0000-0003-4510-9459
authors.initials: BS
authors.lastname: Gill
authors.affiliation: Department of Agronomy, Wheat Genetics Resource Center, Kansas State University, Manhattan, Kansas 66506 (A.D., V.K.V., S.N., D.E.P., M.J.); mithila@ksu.edu.|Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506 (T.V.D., D.-H.K., B.F., B.S.G.); and mithila@ksu.edu.|Department of Crop Sciences, University of Illinois, Urbana-Champaign, Illinois 61801 (P.J.T.) mithila@ksu.edu.
authors.forename: Mithila
authors.identifier: 0000-0003-2065-9067
authors.initials: M
authors.lastname: Jugulam
mesh_terms: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase / Q000235:genetics*; D027721:Amaranthus / Q000187:drug effects* / Q000235:genetics; D032461:Chromosomes, Plant; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005998:Glycine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D053209:Herbicide Resistance / Q000235:genetics*; D006540:Herbicides / Q000008:administration & dosage / Q000494:pharmacology; D007615:Kansas; D020161:Physical Chromosome Mapping; D010940:Plant Proteins / Q000235:genetics; D000097797:Glyphosate
chemical_list: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D005998:Glycine; D006540:Herbicides; D010940:Plant Proteins; D000097797:Glyphosate