Imaging and quantification of lipid in living seed
To study developmental and metabolic factors that control lipid accumulation in seed one should first be able to identify and quantify lipid deposition within the tissues with high accuracy and resolution. For this purpose we designed a toolbox which allows rapid and non-invasive detection and quantitative visualization of lipid in living seeds at a variety of stages using frequency-selected magnetic resonance imaging (Neuberger et al., 2009). The method provides “3D-lipid maps” with a resolution close to cellular level (in-plane 31x 31 m). Steep gradients in local oil storage were defined at organ- and tissue-specific scales. These gradients were closely coordinated with tissue differentiation and seed maturation. The method can be used to elucidate oil accumulation processes in different tissues/organs, as well as to follow the fate of storage lipids during deposition and subsequent mobilization. Further development of noninvasive lipid analytics, which started in 2002 in cooperation with Dr. M. Rockita (Würzburg University), continues in cooperation with Dr. T. Neuberger (Pennsylvania State University, USA). The reliability of the method was demonstrated in wide range of species including barley (Neugerger et al., 2008), oat (Hayden et al., 2011), soybean (Borisjuk et al., 2005), oilseed rape (Neuberger et al., 2009) and cotton (Horn et al., 2012).
Funding: the German Federal Ministry of Education and Research, Deutsche Forschungsgemeinschaft and BayerCropScience.
Grain structure and lipid distribution in barley (A) and soy bean (B).
Cross-section at the median part of seed (left) and lipid content is color-coded and forms a gradient with a maximal level (red) and a minimum level (blue-green) within the tissues. See for details: Borisjuk et al. 2005; Neuberger et al. 2008
Borisjuk L, Rolletschek H, Neuberger T. (2012). Surveying the plant´s world by magnetic resonance imaging. Plant Journal (in press).
Borisjuk L, Rolletschek H, Fuchs J, Melkus G, Neuberger T. (2011). Recent applications of ‘low field’ and ‘high field’ magnetic resonance in seed research. Materials 4: 1426-1439.
Hayden DM, Rolletschek H, Borisjuk L, Corwin J, Kliebenstein DJ, Grimberg A, Stymne S, Dehesh K. (2011). Cofactome analyses reveal enhanced flux of carbon into oil for potential biofuel production. Plant Journal 67: 1018-1028.
Neuberger T, Rolletschek H, Webb A, Borisjuk L. (2009). Non-invasive mapping of lipids in plant tissue using magnetic resonance imaging. Lipidomics, Volume 1: Methods and Protocols, D. Armstrong (ed.), p. 485-496.
Neuberger T, Srenivasulu N, Rokitta M, Rolletschek H, Göbel C, Radchuk V, Feussner I, Wobus U, Webb A, Borisjuk L. (2008). Quantitative imaging of lipid storage in the developing seed. Plant Biotechnology Journal 6: 31-45.
Borisjuk L, Nguyen TH, Neuberger T, Rutten T, Tschiersch H, Claus B, Feussner I, Webb AG, Jacob P, Weber H, Wobus U, Rolletschek H. (2005) Gradients of lipid storage, photosynthesis and plastid differentiation in developing soybean seeds. The New Phytologist 167: 761-776.