title: Liquid chromatography high-resolution mass spectrometry for fatty acid profiling.
abstract: Quantification of fatty acids has been crucial to elucidate lipid biosynthesis pathways in plants. To date, fatty acid identification and quantification has relied mainly on gas chromatography (GC) coupled to flame ionization detection (FID) or mass spectrometry (MS), which requires the derivatization of samples and the use of chemical standards for annotation. Here we present an alternative method based on a simple procedure for the hydrolysis of lipids, so that fatty acids can be quantified by liquid chromatography mass spectrometry (LC-MS) analysis. Proper peak annotation of the fatty acids in the LC-MS-based methods has been achieved by LC-MS measurements of authentic standard compounds and elemental formula annotation supported by (13)C isotope-labeled Arabidopsis. As a proof of concept, we have compared the analysis by LC-MS and GC-FID of two previously characterized Arabidopsis thaliana knock-out mutants for FAD6 and FAD7 desaturase genes. These results are discussed in light of lipidomic profiles obtained from the same samples. In addition, we performed untargeted LC-MS analysis to determine the fatty acid content of two diatom species. Our results indicate that both LC-MS and GC-FID analyses are comparable, but that because of higher sensitivity and selectivity the LC-MS-based method allows for a broader coverage and determination of novel fatty acids.
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam, 14476, Germany.
authors.forename: Mariusz A
authors.initials: MA
authors.lastname: Bromke
authors.forename: Anton
authors.initials: A
authors.lastname: Hochmuth
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tohge
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Patrick
authors.initials: P
authors.lastname: Giavalisco
authors.forename: Asdrubal
authors.initials: A
authors.lastname: Burgos
authors.forename: Lothar
authors.initials: L
authors.lastname: Willmitzer
authors.forename: Yariv
authors.initials: Y
authors.lastname: Brotman
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D002849:Chromatography, Gas; D002853:Chromatography, Liquid / Q000379:methods*; D044943:Fatty Acid Desaturases / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry*; D005410:Flame Ionization; D055786:Gene Knockout Techniques; D050356:Lipid Metabolism; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D029681:Arabidopsis Proteins; D005227:Fatty Acids; D044943:Fatty Acid Desaturases; C084083:Fad7 protein, Arabidopsis; C040448:delta-12 fatty acid desaturase
keywords: Arabidopsis; Biddulphia biddulphiana; GC-FID; LC-MS; Thalassiosira pseudonana; diatoms; fad6; fad7; fatty acid profiling; technical advance