Specific and differential inhibition of very-long-chain fatty acid elongases from Arabidopsis thaliana by different herbicides.

In higher plants, very-long-chain fatty acids (VLCFAs) are the main constituents of hydrophobic polymers that prevent dessication at the leaf surface and provide stability to pollen grains. Of the 21 genes encoding VLCFA elongases (VLCFAEs) from Arabidopsis thaliana, 17 were expressed heterologously in Saccharomyces cerevisiae. Six VLCFAEs, including three known elongases (FAE1, KCS1, and KCS2) and three previously uncharacterized gene products (encoded by At5g43760, At1g04220, and At1g25450) were found to be enzymatically active with endogenous yeast fatty acid substrates and to some extent with externally supplied unsaturated substrates. The spectrum of VLCFAs accumulated in expressing yeast strains was determined by gas chromatography/mass spectrometry. Marked specificity was found among elongases tested with respect to their elongation products, which encompassed saturated and monounsaturated fatty acids 20-30 carbon atoms in length. The active VLCFAEs revealed highly distinct patterns of differential sensitivity to oxyacetamides, chloroacetanilides, and other compounds tested, whereas yeast endogenous VLCFA production, which involves its unrelated elongase (ELO) in sphingolipid synthesis, was unaffected. Several compounds inhibited more than one VLCFAE, and some inhibited all six active enzymes. These findings pinpoint VLCFAEs as the target of the widely used K(3) class herbicides, which have been in commercial use for 50 years, provide important clues as to why spontaneous resistance to this class is rare, and point to complex patterns of substrate specificity and product spectrum among members of the Arabidopsis VLCFAE family.

[1]  P. Mazliak.  LIPID METABOLISM IN PLANTS , 1973 .

[2]  P. Hamm.  Discovery, Development, and Current Status of the Chloroacetamide Herbicides , 1974, Weed Science.

[3]  P. McCourt,et al.  Fatty acid composition of leaf lipids determined after combined digestion and fatty acid methyl ester formation from fresh tissue. , 1986, Analytical biochemistry.

[4]  E. Myers,et al.  Basic local alignment search tool. , 1990, Journal of molecular biology.

[5]  E. Fehling,et al.  Acyl-CoA elongase from a higher plant (Lunaria annua): metabolic intermediates of very-long-chain acyl-CoA products and substrate specificity. , 1991, Biochimica et biophysica acta.

[6]  J. Harwood,et al.  Interaction of thiocarbamate herbicides with fatty acid synthesis in germinating peas and their microsomal fractions , 1991 .

[7]  C. Hollenberg,et al.  An efficient transformation procedure enabling long‐term storage of competent cells of various yeast genera , 1991, Yeast.

[8]  J. Harwood,et al.  Inhibition of fatty acid elongation provides a basis for the action of the herbicide, ethofumesate, on surface wax formation , 1992 .

[9]  I. Sussex,et al.  Fiddlehead: an Arabidopsis mutant constitutively expressing an organ fusion program that involves interactions between epidermal cells. , 1992, Developmental biology.

[10]  R. W. Davis,et al.  A conditional sterile mutation eliminates surface components from Arabidopsis pollen and disrupts cell signaling during fertilization. , 1993, Genes & development.

[11]  D. W. James,et al.  Directed tagging of the Arabidopsis FATTY ACID ELONGATION1 (FAE1) gene with the maize transposon activator. , 1995, The Plant cell.

[12]  M. Uemura,et al.  Cold Acclimation of Arabidopsis thaliana (Effect on Plasma Membrane Lipid Composition and Freeze-Induced Lesions) , 1995, Plant physiology.

[13]  M. Lassner,et al.  A jojoba beta-Ketoacyl-CoA synthase cDNA complements the canola fatty acid elongation mutation in transgenic plants. , 1996, The Plant cell.

[14]  Dusty Post-Beittenmiller,et al.  BIOCHEMISTRY AND MOLECULAR BIOLOGY OF WAX PRODUCTION IN PLANTS. , 1996, Annual review of plant physiology and plant molecular biology.

[15]  D. Toke,et al.  Isolation and Characterization of a Gene Affecting Fatty Acid Elongation in Saccharomyces cerevisiae* , 1996, The Journal of Biological Chemistry.

[16]  L. L. Jackson,et al.  Fatty acid and wax biosynthesis in susceptible and triallate‐resistant Avena fatua L. , 1997 .

[17]  D. Toke,et al.  ELO2 and ELO3, Homologues of theSaccharomyces cerevisiae ELO1 Gene, Function in Fatty Acid Elongation and Are Required for Sphingolipid Formation* , 1997, The Journal of Biological Chemistry.

[18]  L. Kunst,et al.  Very-long-chain fatty acid biosynthesis is controlled through the expression and specificity of the condensing enzyme. , 1997, The Plant journal : for cell and molecular biology.

[19]  A Elofsson,et al.  Prediction of transmembrane alpha-helices in prokaryotic membrane proteins: the dense alignment surface method. , 1997, Protein engineering.

[20]  D. Taylor,et al.  CUT1, an Arabidopsis Gene Required for Cuticular Wax Biosynthesis and Pollen Fertility, Encodes a Very-Long-Chain Fatty Acid Condensing Enzyme , 1999, Plant Cell.

[21]  P. Huijser,et al.  Characterization of the FIDDLEHEAD Gene of Arabidopsis Reveals a Link between Adhesion Response and Cell Differentiation in the Epidermis , 1999, Plant Cell.

[22]  J. Jaworski,et al.  KCS1 encodes a fatty acid elongase 3-ketoacyl-CoA synthase affecting wax biosynthesis in Arabidopsis thaliana. , 1999, The Plant journal : for cell and molecular biology.

[23]  P. Böger,et al.  Towards the primary target of chloroacetamides –new findings pave the way , 2000 .

[24]  Y. Huang,et al.  Identification and characterization of an enzyme involved in the elongation of n-6 and n-3 polyunsaturated fatty acids. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[25]  F. Woodward,et al.  The HIC signalling pathway links CO2 perception to stomatal development , 2000, Nature.

[26]  Robert L. Fischer,et al.  Alterations in CER6, a Gene Identical to CUT1, Differentially Affect Long-Chain Lipid Content on the Surface of Pollen and Stems , 2000, Plant Cell.

[27]  U. Grossniklaus,et al.  FIDDLEHEAD, a gene required to suppress epidermal cell interactions in Arabidopsis, encodes a putative lipid biosynthetic enzyme. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[28]  J. Jaworski,et al.  Active-site residues of a plant membrane-bound fatty acid elongase beta-ketoacyl-CoA synthase, FAE1 KCS. , 2001, Biochimica et biophysica acta.

[29]  J. Warrington,et al.  Identification of a Mammalian Long Chain Fatty Acyl Elongase Regulated by Sterol Regulatory Element-binding Proteins* , 2001, The Journal of Biological Chemistry.

[30]  L. Kunst,et al.  A condensing enzyme from the seeds of Lesquerella fendleri that specifically elongates hydroxy fatty acids. , 2001, Plant physiology.

[31]  R. Reski,et al.  Cloning and functional characterisation of an enzyme involved in the elongation of Delta6-polyunsaturated fatty acids from the moss Physcomitrella patens. , 2002, The Plant journal : for cell and molecular biology.

[32]  H. Ohkawa,et al.  Phytotoxicity and metabolism of ethofumesate in transgenic rice plants expressing the human CYP2B6 gene , 2002 .

[33]  P. Böger,et al.  Covalent binding of chloroacetamide herbicides to the active site cysteine of plant type III polyketide synthases. , 2003, Phytochemistry.

[34]  Flufenacet herbicide treatment phenocopies the fiddlehead mutant in Arabidopsis thaliana. , 2003, Pest management science.

[35]  P. Böger,et al.  Mode of Action for Chloroacetamides and Functionally Related Compounds , 2003 .

[36]  K. Yamato,et al.  Functional Analysis of a β-Ketoacyl-CoA Synthase Gene, MpFAE2, by Gene Silencing in the Liverwort Marchantia polymorpha L. , 2003, Bioscience, biotechnology, and biochemistry.

[37]  D. W. James,et al.  Isolation of EMS-induced mutants in Arabidopsis altered in seed fatty acid composition , 1990, Theoretical and Applied Genetics.

[38]  M. Frentzen,et al.  Functional characterization of β-ketoacyl-CoA synthase genes from Brassica napus L. , 2001, Plant Molecular Biology.