title: Dynamic ¹³C/¹ H NMR imaging uncovers sugar allocation in the living seed.
abstract: Seed growth and accumulation of storage products relies on the delivery of sucrose from the maternal to the filial tissues. The transport route is hidden inside the seed and has never been visualized in vivo. Our approach, based on high-field nuclear magnetic resonance and a custom made (13)C/(1) H double resonant coil, allows the non-invasive imaging and monitoring of sucrose allocation within the seed. The new technique visualizes the main stream of sucrose and determines its velocity during the grain filling in barley (Hordeum vulgare L.). Quantifiable dynamic images are provided, which allow observing movement of (13)C-sucrose at a sub-millimetre level of resolution. The analysis of genetically modified barley grains (Jekyll transgenic lines, seg8 and Risø13 mutants) demonstrated that sucrose release via the nucellar projection towards the endosperm provides an essential mean for the control of seed growth by maternal organism. The sucrose allocation was further determined by structural and metabolic features of endosperm. Sucrose monitoring was integrated with an in silico flux balance analysis, representing a powerful platform for non-invasive study of seed filling in crops.
authors.affiliation: Institute of Experimental Physics, University of Würzburg, Am Hubland, Würzburg, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Melkus
authors.forename: Hardy
authors.initials: H
authors.lastname: Rolletschek
authors.forename: Johannes
authors.initials: J
authors.lastname: Fuchs
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Radchuk
authors.forename: Eva
authors.initials: E
authors.lastname: Grafahrend-Belau
authors.forename: Nese
authors.initials: N
authors.lastname: Sreenivasulu
authors.forename: Twan
authors.initials: T
authors.lastname: Rutten
authors.forename: Diana
authors.initials: D
authors.lastname: Weier
authors.forename: Nicolas
authors.initials: N
authors.lastname: Heinzel
authors.forename: Falk
authors.initials: F
authors.lastname: Schreiber
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Ljudmilla
authors.initials: L
authors.lastname: Borisjuk
mesh_terms: D001692:Biological Transport; D050260:Carbohydrate Metabolism; D002247:Carbon Isotopes / Q000378:metabolism; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D007553:Isotope Labeling; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D013395:Sucrose