title: Lipid changes after leaf wounding in Arabidopsis thaliana: expanded lipidomic data form the basis for lipid co-occurrence analysis.
abstract: A direct-infusion electrospray ionization triple-quadrupole mass spectrometry method with multiple reaction monitoring (MRM) was employed to measure 264 lipid analytes extracted from leaves of Arabidopsis thaliana subjected to mechanical wounding. The method provided precise measurements with an average coefficient of variation of 6.1%. Lipid classes analyzed comprised galactolipids and phospholipids (including monoacyl molecular species, molecular species with oxidized acyl chains, phosphatidic acids (PAs)), tri- and tetra-galactosyldiacylglycerols (TrGDGs and TeGDGs), head-group-acylated galactolipids, and head-group-acylated phosphatidylglycerol (acPG), sulfoquinovosyldiacylglycerols (SQDGs), sphingolipids, di- and tri-acylglycerols (DAGs and TAGs), and sterol derivatives. Of the 264 lipid analytes, 254 changed significantly in response to wounding. In general, levels of structural lipids decreased, whereas monoacyl molecular species, galactolipids and phosphatidylglycerols (PGs) with oxidized fatty acyl chains, PAs, TrGDGs, TeGDGs, TAGs, head-group-acylated galactolipids, acPG, and some sterol derivatives increased, many transiently. The observed changes are consistent with activation of lipid oxidizing, hydrolyzing, glycosylating, and acylating activities in the wounding response. Correlation analysis of the levels of lipid analytes across individual control and treated plants was used to construct a lipid dendrogram and to define clusters and sub-clusters of lipid analytes, each composed of a group of lipids which occurred in a coordinated manner. Current knowledge of metabolism supports the notion that observed sub-clusters comprise lipids generated by a common enzyme and/or metabolically downstream of a common enzyme. This work demonstrates that co-occurrence analysis, based on correlation of lipid levels among plants, is a powerful approach to defining lipids generated in vivo by a common enzymatic pathway.
authors.affiliation: Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS, 66506, USA.
authors.forename: Hieu Sy
authors.initials: HS
authors.lastname: Vu
authors.forename: Sunitha
authors.initials: S
authors.lastname: Shiva
authors.forename: Mary R
authors.initials: MR
authors.lastname: Roth
authors.forename: Pamela
authors.initials: P
authors.lastname: Tamura
authors.forename: Lianqing
authors.initials: L
authors.lastname: Zheng
authors.forename: Maoyin
authors.initials: M
authors.lastname: Li
authors.forename: Sujon
authors.initials: S
authors.lastname: Sarowar
authors.forename: Samuel
authors.initials: S
authors.lastname: Honey
authors.forename: Dedan
authors.initials: D
authors.lastname: McEllhiney
authors.forename: Paul
authors.initials: P
authors.lastname: Hinkes
authors.forename: Lawrence
authors.initials: L
authors.lastname: Seib
authors.forename: Todd D
authors.initials: TD
authors.lastname: Williams
authors.forename: Gary
authors.initials: G
authors.lastname: Gadbury
authors.forename: Xuemin
authors.initials: X
authors.lastname: Wang
authors.forename: Jyoti
authors.initials: J
authors.lastname: Shah
authors.forename: Ruth
authors.initials: R
authors.lastname: Welti
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D038983:Galactolipids / Q000032:analysis / Q000378:metabolism; D008055:Lipids / Q000032:analysis* / Q000737:chemistry*; D010712:Phosphatidic Acids / Q000032:analysis / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D038983:Galactolipids; D008055:Lipids; D010712:Phosphatidic Acids; D010743:Phospholipids
keywords: Arabidopsis thaliana; Spearman's correlation; dendrogram; direct-infusion triple-quadrupole mass spectrometry; glycerolipids; leaf wounding; lipid clustering; lipidomics; oxidized lipids; sterol derivatives; technical advance