title: Differential regulation of two sucrose transporters by defoliation and light conditions in perennial ryegrass.
abstract: Sucrose transport between source and sink tissues is supposed to be a key-step for an efficient regrowth of perennial rye-grass after defoliation and might be altered by light conditions. We assessed the effect of different light regimes (high vs low light applied before or after defoliation) on growth, fructans and sucrose mobilization, as well as on sucrose transporter expression during 14 days of regrowth. Our results reported that defoliation led to a mobilization of C reserves (first sucrose and then fructans), which was parallel to an induction of LpSUT1 sucrose transporter expression in source and sink tissues (i.e. leaf sheaths and elongating leaf bases, respectively) irrespective to light conditions. Light regime (high or low light) had little effects on regrowth and on C reserves mobilization during the first 48 h of regrowth after defoliation. Thereafter, low light conditions, delaying the recovery of photosynthetic capacities, had a negative effect on C reserves re-accumulation (especially sucrose). Surprisingly, high light did not enhance sucrose transporter expression. Indeed, while light conditions had no effect on LpSUT1 expression, LpSUT2 transcripts levels were enhanced for low light grown plants. These results indicate that two sucrose transporter currently identified in Lolium perenne L. are differentially regulated by light and sucrose.
authors.affiliation: UMR INRA-UCBN 950, Ecophysiologie Végétale, Agronomie and nutritions NCS, IRBA, Esplanade de la Paix, Université de Caen, F-14032 Caen Cedex, France.
authors.forename: Pierre-Maxime
authors.initials: PM
authors.lastname: Furet
authors.forename: Alexandre
authors.initials: A
authors.lastname: Berthier
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Decau
authors.forename: Annette
authors.initials: A
authors.lastname: Morvan-Bertrand
authors.forename: Marie-Pascale
authors.initials: MP
authors.lastname: Prud'homme
authors.forename: Nathalie
authors.initials: N
authors.lastname: Noiraud-Romy
authors.forename: Frédéric
authors.initials: F
authors.lastname: Meuriot
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001692:Biological Transport; D002244:Carbon / Q000378:metabolism*; D005630:Fructans / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008027:Light; D008129:Lolium / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D010788:Photosynthesis; D018515:Plant Leaves / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D013395:Sucrose / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D005630:Fructans; D026901:Membrane Transport Proteins; D010940:Plant Proteins; C078729:sucrose transport protein, plant; D013395:Sucrose; D002244:Carbon