Comparative plant sphingolipidomic reveals specific lipids in seeds and oil.

Plant sphingolipids are a highly diverse family of structural and signal lipids. Owing to their chemical diversity and complexity, a powerful analytical method was required to identify and quantify a large number of individual molecules with a high degree of structural accuracy. By using ultra-performance liquid chromatography with a single elution system coupled to electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) in the positive multiple reaction monitoring (MRM) mode, detailed sphingolipid composition was analyzed in various tissues of two Brassicaceae species Arabidopsis thaliana and Camelina sativa. A total of 300 molecular species were identified defining nine classes of sphingolipids, including Cers, hCers, Glcs and GIPCs. High-resolution mass spectrometry identified sphingolipids including amino- and N-acylated-GIPCs. The comparative analysis of seedling, seed and oil sphingolipids showed tissue specific distribution suggesting metabolic channeling and compartmentalization.