Dynamic 13C/1H NMR imaging uncovers sugar allocation in the living seed

• DOI: 10.1111/j.1467-7652.2011.00618.x
• Publication Date: 2011-04-29T01:47:48Z
• Authors: Gerd Melkus; Hardy Rolletschek; Johannes Fuchs; Volodymyr Radchuk; Eva Grafahrend‐Belau; Nese Sreenivasulu; Twan Rutten; Diana Weier; Nicolas Heinzel; Falk Schreiber; Thomas Altmann; Peter M Jakob; Ljudmilla Borisjuk
• Keywords: 2. Zero hunger; 0303 health sciences; 03 medical and health sciences

SummarySeed 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 13C/1H 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 13C‐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.