title: Three Arabidopsis fatty acyl-coenzyme A reductases, FAR1, FAR4, and FAR5, generate primary fatty alcohols associated with suberin deposition.
abstract: Suberin is a protective hydrophobic barrier consisting of phenolics, glycerol, and a variety of fatty acid derivatives, including C18:0-C22:0 primary fatty alcohols. An eight-member gene family encoding alcohol-forming fatty acyl-coenzyme A reductases (FARs) has been identified in Arabidopsis (Arabidopsis thaliana). Promoter-driven expression of the beta-glucuronidase reporter gene indicated that three of these genes, FAR1(At5g22500), FAR4(At3g44540), and FAR5(At3g44550), are expressed in root endodermal cells. The three genes were transcriptionally induced by wounding and salt stress. These patterns of gene expression coincide with known sites of suberin deposition. We then characterized a set of mutants with T-DNA insertions in FAR1, FAR4, or FAR5 and found that the suberin compositions of roots and seed coats were modified in each far mutant. Specifically, C18:0-OH was reduced in far5-1, C20:0-OH was reduced in far4-1, and C22:0-OH was reduced in far1-1. We also analyzed the composition of polymer-bound lipids of leaves before and after wounding and found that the basal levels of C18:0-C22:0 primary alcohols in wild-type leaves were increased by wounding. In contrast, C18:0-OH and C22:0-OH were not increased by wounding in far5-1 and far1-1 mutants, respectively. Heterologous expression of FAR1, FAR4, and FAR5 in yeast confirmed that they are indeed active alcohol-forming FARs with distinct, but overlapping, chain length specificities ranging from C18:0 to C24:0. Altogether, these results indicate that Arabidopsis FAR1, FAR4, and FAR5 generate the fatty alcohols found in root, seed coat, and wound-induced leaf tissue.
authors.affiliation: Laboratoire de Biogenèse Membranaire, Université Victor Ségalen Bordeaux 2, CNRS, UMR 5200, 33076 Bordeaux cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Domergue
authors.forename: Sollapura J
authors.initials: SJ
authors.lastname: Vishwanath
authors.forename: Jérôme
authors.initials: J
authors.lastname: Joubès
authors.forename: Jasmine
authors.initials: J
authors.lastname: Ono
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Lee
authors.forename: Matthieu
authors.initials: M
authors.lastname: Bourdon
authors.forename: Reem
authors.initials: R
authors.lastname: Alhattab
authors.forename: Christine
authors.initials: C
authors.lastname: Lowe
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Pascal
authors.forename: René
authors.initials: R
authors.lastname: Lessire
authors.forename: Owen
authors.initials: O
authors.lastname: Rowland
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005233:Fatty Alcohols / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008055:Lipids / Q000096:biosynthesis*; D016254:Mutagenesis, Insertional; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology; D018749:RNA, Plant / Q000235:genetics; D012639:Seeds / Q000201:enzymology; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; C120919:FAR1 protein, Arabidopsis; D005233:Fatty Alcohols; D008055:Lipids; D009687:Nuclear Proteins; D018749:RNA, Plant; C065875:suberin; D000445:Aldehyde Oxidoreductases; C021351:hexadecanal dehydrogenase (acylating)