J Inte Plant Bio:Lipidomic profiling analysis reveals the dynamic changes of phospholipid molecules

High-throughput lipidomic profiling provides a sensitive approach for discovering minor lipid species. By using an advance in electrospray ionization tandem mass spectrometry, a large set of phospholipid molecular species (126 species) with high resolution were identified from Arabidopsis. Thirty one of these are newly identified (16 are unique in plants), including 13 species of phosphatidic acid (PA), 9 phosphatidylcholine (PC), 6 phosphatidylinositol (PI) and 3 phosphatidylserine (PS). Further analysis of the lipidomic profile reveals dynamic changes of phospholipids and distinct species alterations during seedling development. PA molecules are found at the lowest levels in imbibition and follow an increasing trend during seedling growth, while PE molecules show the opposite pattern with highest levels at imbibition and a general decreasing trend at later stages. Of PA molecular species, 34:2-, 34:3-, 36:4-, 36:5-, 38:3- and 38:4-PA increase during radicle emergence, and 34:2, 34:3 species reach highest levels during hypocotyl and cotyledon emergence from the seed coat. Conversely, molecular species of PE show higher level in imbibition and decrease in later stages. These results suggest crucial roles of specific molecular species and homeostasis of phospholipid molecules in seedling growth and provide insights into the mechanisms regulating plant development.