title: Spatio-temporal dynamics of fructan metabolism in developing barley grains.
abstract: Barley (Hordeum vulgare) grain development follows a series of defined morphological and physiological stages and depends on the supply of assimilates (mainly sucrose) from the mother plant. Here, spatio-temporal patterns of sugar distributions were investigated by mass spectrometric imaging, targeted metabolite analyses, and transcript profiling of microdissected grain tissues. Distinct spatio-temporal sugar balances were observed, which may relate to differentiation and grain filling processes. Notably, various types of oligofructans showed specific distribution patterns. Levan- and graminan-type oligofructans were synthesized in the cellularized endosperm prior to the commencement of starch biosynthesis, while during the storage phase, inulin-type oligofructans accumulated to a high concentration in and around the nascent endosperm cavity. In the shrunken endosperm mutant seg8, with a decreased sucrose flux toward the endosperm, fructan accumulation was impaired. The tight partitioning of oligofructan biosynthesis hints at distinct functions of the various fructan types in the young endosperm prior to starch accumulation and in the endosperm transfer cells that accomplish the assimilate supply toward the endosperm at the storage phase.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Stadt Seeland, OT Gatersleben, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Peukert
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Stadt Seeland, OT Gatersleben, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Thiel
authors.affiliation: Lab of Molecular Plant Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee (2434), Belgium.
authors.forename: Darin
authors.initials: D
authors.lastname: Peshev
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Stadt Seeland, OT Gatersleben, Germany.
authors.forename: Winfriede
authors.initials: W
authors.lastname: Weschke
authors.affiliation: Lab of Molecular Plant Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee (2434), Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Van den Ende
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Stadt Seeland, OT Gatersleben, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Mock
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Stadt Seeland, OT Gatersleben, Germany matros@ipk-gatersleben.de.
authors.forename: Andrea
authors.initials: A
authors.lastname: Matros
mesh_terms: D005630:Fructans / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D017665:Hydroxyl Radical / Q000378:metabolism; D007477:Ions; D055442:Metabolome; D009154:Mutation / Q000235:genetics; D009844:Oligosaccharides / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D005630:Fructans; D007477:Ions; D009844:Oligosaccharides; D017665:Hydroxyl Radical