title: Spatial and Temporal Mapping of Key Lipid Species inBrassica napusSeeds.
abstract: The regulation of lipid synthesis in oil seeds is still not fully understood. Oilseed rape (Brassica napus) is the third most productive vegetable oil crop on the global market; therefore, increasing our understanding of lipid accumulation in oilseed rape seeds is of great economic, as well as intellectual, importance. Matrix-assisted laser/desorption ionization-mass spectrometry imaging (MALDI-MSI) is a technique that allows the mapping of metabolites directly onto intact biological tissues, giving a spatial context to metabolism. We have used MALDI-MSI to study the spatial distribution of two major lipid species, triacylglycerols and phosphatidylcholines. A dramatic, heterogenous landscape of molecular species was revealed, demonstrating significantly different lipid compositions between the various tissue types within the seed. The embryonic axis was found to be particularly enriched in palmitic acid, while the seed coat/aleurone layer accumulated vaccenic, linoleic, and α-linoleic acids. Furthermore, the lipid composition of the inner and outer cotyledons differed from each other, a remarkable discovery given the supposed identical functionality of these two tissues. Triacylglycerol and phosphatidylcholine molecular species distribution was analyzed through a developmental time series covering early seed lipid accumulation to seed maturity. The spatial patterning of lipid molecular species did not vary significantly during seed development. Data gathered using MALDI-MSI was verified through gas chromatography analysis of dissected seeds. The distinct lipid distribution profiles observed imply differential regulation of lipid metabolism between the different tissue types of the seed. Further understanding of this differential regulation will enhance efforts to improve oilseed rape productivity and quality.
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.).|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.).
authors.forename: Helen K
authors.identifier: 0000-0002-0839-6105
authors.initials: HK
authors.lastname: Woodfield
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.).|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.).
authors.forename: Drew
authors.initials: D
authors.lastname: Sturtevant
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.).|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.).
authors.forename: Ljudmilla
authors.identifier: 0000-0001-6910-0841
authors.initials: L
authors.lastname: Borisjuk
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.).|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.).
authors.forename: Eberhard
authors.identifier: 0000-0002-4994-3304
authors.initials: E
authors.lastname: Munz
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.).|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.).
authors.forename: Irina A
authors.initials: IA
authors.lastname: Guschina
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.); kent.chapman@unt.edu harwood@cardiff.ac.uk.|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and kent.chapman@unt.edu harwood@cardiff.ac.uk.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.) kent.chapman@unt.edu harwood@cardiff.ac.uk.
authors.forename: Kent
authors.identifier: 0000-0003-0489-3072
authors.initials: K
authors.lastname: Chapman
authors.affiliation: Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, United Kingdom (H.K.W., I.A.G., J.L.H.); kent.chapman@unt.edu harwood@cardiff.ac.uk.|Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203-5017 (D.S., K.C.); and kent.chapman@unt.edu harwood@cardiff.ac.uk.|Leibniz Institute of Plant Genetics and Crop Research, D-06466 Gatersleben, Germany (L.B., E.M.) kent.chapman@unt.edu harwood@cardiff.ac.uk.
authors.forename: John L
authors.identifier: 0000-0003-2377-2612
authors.initials: JL
authors.lastname: Harwood
mesh_terms: D029688:Brassica napus / Q000378:metabolism*; D002849:Chromatography, Gas; D018548:Cotyledon / Q000378:metabolism; D019787:Linoleic Acid / Q000032:analysis; D008055:Lipids / Q000096:biosynthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009829:Oleic Acids / Q000032:analysis; D019308:Palmitic Acid / Q000032:analysis; D010713:Phosphatidylcholines / Q000096:biosynthesis / Q000737:chemistry; D010938:Plant Oils / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism*; D062211:Spatio-Temporal Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D014280:Triglycerides / Q000096:biosynthesis / Q000737:chemistry
chemical_list: D008055:Lipids; D009829:Oleic Acids; D010713:Phosphatidylcholines; D010938:Plant Oils; D014280:Triglycerides; D019308:Palmitic Acid; D019787:Linoleic Acid; C050413:11-octadecenoic acid