title: Inhibition of polyunsaturated fatty acid accumulation in plants expressing a fatty acid epoxygenase.
abstract: Earlier, we described the isolation of a Crepis palaestina cDNA (Cpal2) which encoded a Delta12-epoxygenase that could catalyse the synthesis of 12,13-epoxy-cis-9-octadecenoic acid (18:1E) from linoleic acid (18:2). When the Cpal2 gene was expressed under the control of a seed-specific promoter in Arabidopsis, plants were able to accumulate small amounts 18:1E and 12,13-epoxy-cis-9,15-octadec-2-enoic acid in their seed lipids. In this report we give results obtained from a detailed analysis of transgenic Arabidopsis plants containing the Cpal2 gene. The seeds from these plants accumulate varying levels of 18:1E, but show a marked increase in 18:1 and equivalent decrease in 18:2 and 18:3. We further observed that the co-expression of a C. palaestina Delta12-desaturase in Arabidopsis appears to return the relative proportions of the C(18) seed fatty acids to normal levels and results in a 2-fold increase in total epoxy fatty acids.
authors.affiliation: CSIRO Plant Industry, GPO Box 1600, Canberra, Australia. surinder.singh@pi.csiro.au
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: S
authors.initials: S
authors.lastname: Thomaeus
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.forename: A
authors.initials: A
authors.lastname: Green
authors.forename: S
authors.initials: S
authors.lastname: Stymne
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D019659:Asteraceae / Q000201:enzymology / Q000235:genetics*; D004852:Epoxy Compounds / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D009829:Oleic Acids / Q000378:metabolism*; D010088:Oxidoreductases; D010940:Plant Proteins; D030821:Plants, Genetically Modified / Q000378:metabolism*; D011401:Promoter Regions, Genetic
chemical_list: C119104:12,13-epoxy-9-octadecenoic acid; D004852:Epoxy Compounds; D005231:Fatty Acids, Unsaturated; D009829:Oleic Acids; D010940:Plant Proteins; D010088:Oxidoreductases; C111963:epoxygenase, Crepis palaestina; D044943:Fatty Acid Desaturases