Lipid changes after leaf wounding in Arabidopsis thaliana: expanded lipidomic data form the basis for lipid co‐occurrence analysis

• Published in: The Plant journal : for cell and molecular biology Vol. 80; no. 4; pp. 728 - 743
• Main Authors: Vu, Hieu Sy, Shiva, Sunitha, Roth, Mary R, Tamura, Pamela, Zheng, Lianqing, Li, Maoyin, Sarowar, Sujon, Honey, Samuel, McEllhiney, Dedan, Hinkes, Paul, Seib, Lawrence, Williams, Todd D, Gadbury, Gary, Wang, Xuemin, Shah, Jyoti, Welti, Ruth
• Format: Journal Article
• Language: English
• Published: England Blackwell Scientific Publishers and BIOS Scientific Publishers in association with the Society for Experimental Biology 01.11.2014; Blackwell Publishing Ltd
• Subjects: acids; Arabidopsis - metabolism; Arabidopsis thaliana; dendrogram; direct‐infusion triple–quadrupole mass spectrometry; Enzymes; galactolipids; Galactolipids - analysis; Galactolipids - metabolism; glycerolipids; ionization; leaf wounding; Leaves; lipid clustering; lipidomics; Lipids; Lipids - analysis; Lipids - chemistry; Mass spectrometry; metabolism; monitoring; oxidized lipids; Phosphatidic Acids - analysis; Phosphatidic Acids - metabolism; phosphatidylglycerols; Phospholipids - analysis; Plant biology; Plant Leaves - chemistry; Plant Leaves - metabolism; Spearman's correlation; Spectrometry, Mass, Electrospray Ionization - methods; sphingolipids; sterol derivatives; Sterols; technical advance; Arabidopsis thaliana; glycerolipids; lipid clustering; sterol derivatives; direct-infusion triple-quadrupole mass spectrometry; technical advance; Spearman's correlation; leaf wounding; oxidized lipids; dendrogram; lipidomics
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/tpj.12659

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.