title: A bacterial artificial chromosome (BAC) genomic approach reveals partial clustering of the furanocoumarin pathway genes in parsnip.
abstract: Furanocoumarins are specialized metabolites that are involved in the defense of plants against phytophagous insects. The molecular and functional characterization of the genes involved in their biosynthetic pathway is only partially complete. Many recent reports have described gene clusters responsible for the biosynthesis of specialized metabolites in plants. To investigate possible co-localization of the genes involved in the furanocoumarin pathway, we sequenced parsnip BAC clones spanning two different gene loci. We found that two genes previously identified in this pathway, CYP71AJ3 and CYP71AJ4, were located on the same BAC, whereas a third gene, PsPT1, belonged to a different BAC clone. Chromosome mapping using fluorescence in situ hybridization (FISH) indicated that PsPT1 and the CYP71AJ3-CYP71AJ4 clusters are located on two different chromosomes. Sequencing the BAC clone harboring PsPT1 led to the identification of a gene encoding an Fe(II) α-ketoglutarate-dependent dioxygenase (PsDIOX) situated in the neighborhood of PsPT1 and confirmed the occurrence of a second gene cluster involved in the furanocoumarin pathway. This enzyme metabolizes p-coumaroyl CoA, leading exclusively to the synthesis of umbelliferone, an important intermediate compound in furanocoumarin synthesis. This work provides an insight into the genomic organization of genes from the furanocoumarin biosynthesis pathway organized in more than one gene cluster. It also confirms that the screening of a genomic library and the sequencing of BAC clones represent a valuable tool to identify genes involved in biosynthetic pathways dedicated to specialized metabolite synthesis.
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Sandro
authors.initials: S
authors.lastname: Roselli
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Olry
authors.affiliation: Centre National de Ressources Génomiques Végétales - INRA - 24 Chemin de Borde Rouge - Auzeville CS 52627, 31326, Castanet Tolosan Cedex, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Vautrin
authors.affiliation: Plate-Forme de Cytogénétique Moléculaire - UMR1349 IGEPP INRA - Agrocampus Ouest-Université de Rennes 1, 35653, Le Rheu, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Coriton
authors.affiliation: INRIA Nancy Grand Est, 615 rue du Jardin Botanique, 54600, Villers-lès-Nancy, France.
authors.forename: Dave
authors.initials: D
authors.lastname: Ritchie
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Gianni
authors.initials: G
authors.lastname: Galati
authors.affiliation: Institut de biologie moléculaire des plantes - UPR2357 CNRS, Université de Strasbourg, 12 rue du Général Zimmer - 67084, Strasbourg Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Navrot
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Célia
authors.initials: C
authors.lastname: Krieger
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Guilhem
authors.initials: G
authors.lastname: Vialart
authors.affiliation: Centre National de Ressources Génomiques Végétales - INRA - 24 Chemin de Borde Rouge - Auzeville CS 52627, 31326, Castanet Tolosan Cedex, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Bergès
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bourgaud
authors.affiliation: Laboratoire Agronomie et Environnement, INRA UMR1121, 2 avenue de la forêt de Haye TSA 40602, 54518, Vandœuvre-lès-Nancy, France.|Laboratoire Agronomie et Environnement, Université de Lorraine UMR1121, 2 avenue de la forêt de Haye - TSA 40602, 54518, Vandœuvre-lès-Nancy, France.
authors.forename: Alain
authors.identifier: http://orcid.org/0000-0003-4507-8031
authors.initials: A
authors.lastname: Hehn
mesh_terms: D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D004122:Dimethylallyltranstransferase / Q000235:genetics / Q000378:metabolism; D011564:Furocoumarins / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D028529:Pastinaca / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D011564:Furocoumarins; D010940:Plant Proteins; D004122:Dimethylallyltranstransferase
keywords: 
  Pastinaca sativa
  ; P450; bacterial artificial chromosome; bacterial artificial chromosome-fluorescence in situ hybridization; cluster; furanocoumarin; prenyltransferase; α-ketoglutarate-dependent dioxygenase