title: Increasing seed oil content in oil-seed rape (Brassica napus L.) by over-expression of a yeast glycerol-3-phosphate dehydrogenase under the control of a seed-specific promoter.
abstract: Previous attempts to manipulate oil synthesis in plants have mainly concentrated on the genes involved in the biosynthesis and use of fatty acids, neglecting the possible role of glycerol-3-phosphate supply on the rate of triacylglycerol synthesis. In this study, a yeast gene coding for cytosolic glycerol-3-phosphate dehydrogenase (gpd1) was expressed in transgenic oil-seed rape under the control of the seed-specific napin promoter. It was found that a twofold increase in glycerol-3-phosphate dehydrogenase activity led to a three- to fourfold increase in the level of glycerol-3-phosphate in developing seeds, resulting in a 40% increase in the final lipid content of the seed, with the protein content remaining substantially unchanged. This was accompanied by a decrease in the glycolytic intermediate dihydroxyacetone phosphate, the direct precursor of glycerol-3-phosphate dehydrogenase. The levels of sucrose and various metabolites in the pathway from sucrose to fatty acids remained unaltered. The results show that glycerol-3-phosphate supply co-limits oil accumulation in developing seeds. This has important implications for strategies that aim to increase the overall level of oil in commercial oil-seed crops for use as a renewable alternative to petrol.
authors: Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany.
authors: Helene
authors: H
authors: Vigeolas
authors: Peter
authors: P
authors: Waldeck
authors: Thorsten
authors: T
authors: Zank
authors: Peter
authors: P
authors: Geigenberger
mesh_terms: D029688:Brassica napus / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D010938:Plant Oils / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000378:metabolism; D011401:Promoter Regions, Genetic; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
chemical_list: D005227:Fatty Acids; D005994:Glycerophosphates; D010938:Plant Oils; D029701:Saccharomyces cerevisiae Proteins; C029620:alpha-glycerophosphoric acid; D005993:Glycerolphosphate Dehydrogenase