title: Root-specific expression of opine genes and opine accumulation in some cultivars of the naturally occurring genetically modified organism Nicotiana tabacum.
abstract: Previous studies have shown that Nicotiana tabacum contains three Agrobacterium-derived T-DNA sequences inherited from its paternal ancestor Nicotiana tomentosiformis. Among these, the TB locus carries an intact mannopine synthase 2' gene (TB-mas2'). This gene is similar to the Agrobacterium rhizogenes A4-mas2' gene that encodes the synthesis of the Amadori compound deoxyfructosyl-glutamine (DFG or santhopine). In this study we show that TB-mas2' is expressed at very low levels in N. tomentosiformis and in most N. tabacum cultivars; however, some cultivars show high TB-mas2' expression levels. The TB-mas2' promoter sequences of low- and high-expressing cultivars are identical. The low/high level of expression segregates as a single Mendelian factor in a cross between a low- and a high-expression cultivar. pTB-mas2'-GUS and pA4-mas2'-GUS reporter genes were stably introduced in N. benthamiana. Both were mainly expressed in the root expansion zone and leaf vasculature. Roots of tobacco cultivars with high TB-mas2' expression contain detectable levels of DFG.
authors.affiliation: Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes, Rue du Général Zimmer 12, Strasbourg, 67084, France.
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
authors.affiliation: Imperial Tobacco Bergerac, La Tour, Bergerac, 24100, France.
authors.forename: François Dorlhac
authors.initials: FD
authors.lastname: de Borne
authors.affiliation: Imperial Tobacco Bergerac, La Tour, Bergerac, 24100, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Julio
authors.affiliation: Laboratoire de synthèse, réactivité organiques et catalyse, Institut de Chimie, UMR 7177, Université de Strasbourg, 4 Rue Blaise Pascal, Strasbourg, 67070, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Obszynski
authors.affiliation: Laboratoire de synthèse, réactivité organiques et catalyse, Institut de Chimie, UMR 7177, Université de Strasbourg, 4 Rue Blaise Pascal, Strasbourg, 67070, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Pale
authors.affiliation: Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes, Rue du Général Zimmer 12, Strasbourg, 67084, France. leon.otten@ibmp-cnrs.unistra.fr.
authors.forename: Léon
authors.initials: L
authors.lastname: Otten
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D010940:Plant Proteins; C036483:T-DNA; D006836:Hydro-Lyases; C070395:mannopine synthase
keywords: Nicotiana tabacum; T-DNA; natural transformant; opine synthesis