title: Engineering vitamin E content: from Arabidopsis mutant to soy oil.
abstract: We report the identification and biotechnological utility of a plant gene encoding the tocopherol (vitamin E) biosynthetic enzyme 2-methyl-6-phytylbenzoquinol methyltransferase. This gene was identified by map-based cloning of the Arabidopsis mutation vitamin E pathway gene3-1 (vte3-1), which causes increased accumulation of delta-tocopherol and decreased gamma-tocopherol in the seed. Enzyme assays of recombinant protein supported the hypothesis that At-VTE3 encodes a 2-methyl-6-phytylbenzoquinol methyltransferase. Seed-specific expression of At-VTE3 in transgenic soybean reduced seed delta-tocopherol from 20 to 2%. These results confirm that At-VTE3 protein catalyzes the methylation of 2-methyl-6-phytylbenzoquinol in planta and show the utility of this gene in altering soybean tocopherol composition. When At-VTE3 was coexpressed with At-VTE4 (gamma-tocopherol methyltransferase) in soybean, the seed accumulated to >95% alpha-tocopherol, a dramatic change from the normal 10%, resulting in a greater than eightfold increase of alpha-tocopherol and an up to fivefold increase in seed vitamin E activity. These findings demonstrate the utility of a gene identified in Arabidopsis to alter the tocopherol composition of commercial seed oils, a result with both nutritional and food quality implications.
authors: Monsanto Company, Calgene Campus, Davis, California 95616, USA.
authors: Alison L
authors: AL
authors: Van Eenennaam
authors: Kim
authors: K
authors: Lincoln
authors: Timothy P
authors: TP
authors: Durrett
authors: Henry E
authors: HE
authors: Valentin
authors: Christine K
authors: CK
authors: Shewmaker
authors: Greg M
authors: GM
authors: Thorne
authors: Jian
authors: J
authors: Jiang
authors: Susan R
authors: SR
authors: Baszis
authors: Charlene K
authors: CK
authors: Levering
authors: Eric D
authors: ED
authors: Aasen
authors: Ming
authors: M
authors: Hao
authors: Joshua C
authors: JC
authors: Stein
authors: Susan R
authors: SR
authors: Norris
authors: Robert L
authors: RL
authors: Last
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D030821:Plants, Genetically Modified; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013024:Soybean Oil / Q000378:metabolism*; D013025:Glycine max / Q000201:enzymology / Q000235:genetics; D024505:Tocopherols / Q000378:metabolism*; D014810:Vitamin E / Q000096:biosynthesis*
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D014810:Vitamin E; D013024:Soybean Oil; C483729:2-methyl-6-phytylbenzoquinol methyltransferase, Arabidopsis; C447422:2-methyl-6-phytylbenzoquinone methyltransferase; D008780:Methyltransferases; C479072:delta-tocopherol; D024505:Tocopherols