title: Fate of fructose supplied to leaf sheaths after defoliation of Lolium perenne L.: assessment by 13C-fructose labelling.
abstract: The role of fructans from leaf sheaths for the refoliation of Lolium perenne after severe defoliation was assessed by following the fate of (13)C-fructose supplied to leaf sheaths at the time of defoliation. At the end of the 4 h labelling period on defoliated plants, 77% of the (13)C incorporated was still located in leaf sheaths. Only 4% and 0.9% were, respectively, allocated to stem and roots, while 18% was imported by the growing leaves where (13)C was allocated first to the proximal part of the leaf growth zone (0-10 mm). In all tissues, the most highly (13)C-labelled carbohydrates was not fructose but sucrose. In leaf sheaths, (13)C-loliose was produced. In the leaf growth zone (0-20 mm), fructans were simultanously synthesized from (13)C entering the leaves and degraded. The export of (13)C from leaf sheaths continued during the first day of regrowth but stopped afterwards. There was no net loss of C from (13)C-fructose over the first 2 d of regrowth. The role of fructans and loliose is discussed as well as the physiological mechanisms contributing to defoliation tolerance in L. perenne.
authors.affiliation: UMR INRA-UCBN Physiologie et Biochimie Végétales, IRBA, Université de Caen, Esplanade de la Paix, F-14032 CAEN cedex, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Amiard
authors.forename: Annette
authors.initials: A
authors.lastname: Morvan-Bertrand
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Billard
authors.forename: Claude
authors.initials: C
authors.lastname: Huault
authors.forename: Marie-Pascale
authors.initials: MP
authors.lastname: Prud'homme
mesh_terms: D050260:Carbohydrate Metabolism; D002247:Carbon Isotopes; D005630:Fructans / Q000378:metabolism; D005632:Fructose / Q000378:metabolism* / Q000494:pharmacology; D006601:Hexoses / Q000378:metabolism; D008129:Lolium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008954:Models, Biological; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D005630:Fructans; D006601:Hexoses; D005632:Fructose; D013395:Sucrose