title: Plant lipidomics based on hydrophilic interaction chromatography coupled to ion trap time-of-flight mass spectrometry.
abstract: Plants synthesize a wide range of hydrophobic compounds, generally known as lipids. Here, we report an application of liquid chromatography ion trap time-of-flight mass spectrometry (LC-IT-TOF-MS) for plant lipidomics. Using hydrophilic interaction chromatography (HILIC) for class separation, typical membrane lipids including glycerolipids, steryl glucosides and glucosylceramides, and hydrophobic plant secondary metabolites such as saponins were analyzed simultaneously. By this method, we annotated approximately 100 molecules fromArabidopsis thaliana. To demonstrate the application of this method to biological study, we analyzedArabidopsismutanttrigalactosyldiacylglycerol3(tgd3), which has a complex metabolic phenotype including the accumulation of unusual forms of galactolipids. Lipid profiling by LC-MS revealed thattgd3accumulated an unusual form of digalactosyldiacylglycerol, annotated as Gal(β1 → 6)βGalDG. The compositional difference between normal and unusual forms of digalactosyldiacylglycerol was detected by this method. In addition, we analyzed well-knownArabidopsismutantsats1-1,fad6-1,andfad7-2, which are also disrupted in lipid metabolic genes. Untargeted lipidome analysis coupled with multivariate analysis clearly discriminated the mutants and their distinctive metabolites. These results indicated that HILIC-MS is an efficient method for plant lipidomics.
authors: RIKEN Plant Science Center, Tsurumi-ku, Yokohama, 230-0045 Japan.
authors: Yozo
authors: Y
authors: Okazaki
authors: Yukiko
authors: Y
authors: Kamide
authors: Masami Yokota
authors: MY
authors: Hirai
authors: Kazuki
authors: K
authors: Saito
keywords: Hydrophilic interaction chromatography; Ion trap time-of-flight mass spectrometry; Lipidome; Lipidomics