Abstract: This paper employed a sensitive approach based on electrospray ionization tandem mass spectrometry (ESI-MS􊄯MS) to comprehensively analyze lipid composition changes in response tomechanical wounding in Arabidopsis thaliana.The changes of 6 phospholipid classes, 2 glycolipid classes, and 3 lysophospholipid, and 120 lipid molecular species in total depicted the basic
tendency of membrane lipids in response to wounding for 0 , 15, 30 , and 60min in Arabidopsis thaliana . The results showed that wounding can lead to increase phosphatidic acid (PA) and 3 lysophospholipid and decrease glycolipids of the major chloroplast plastidic lipids . The increasing speed and intensity of PA produced by various lipids are very different , which shows those lipids have experienced different biochemistry processes . (1) The accumulation of 34∶4 PA derived from plastidic lipid 34∶4 PG (phosphatidylglycerol) is significantly slower than that of other PA species; (2) 34∶6 PA accumulated a little and possibly derived from the 34∶6 MGDG or DGDG . However , the content of both glycolipids has apparently decreased, which indicated they are possibly involved in other reactions. No remarkable changes of lipid mole percentage were observed .

Key words: Mechanical wounding