ESI-MS/MS方法检测拟南芥膜脂分子对机械伤害的响应

Profiling the Changes of Lipid Molecular Species in Response to Wounding in Arabidopsis thaliana (Cruciferae) by ESI-MS/MS

利用一种灵敏的、基于ESI-MS/MS(electrospray ionization tandem mass spectrometry)的脂类组学方法,测定了机械伤害诱导的拟南芥6种磷脂(phospholipids)、2种糖脂(glycolipids)、3种溶血磷脂(lysophospho-lipids)和约120种脂类分子的变化,探索了膜脂响应机械伤害的基本趋势。结果表明,机械伤害后磷脂酸(phosphatidic acid,PA)和3种溶血磷脂显著升高,而叶绿体膜上的糖脂减少;在测量的1小时范围内,不同脂类水解产生的磷脂酸分子的增加速度和强度不同,反映出它们经历了不同的生化过程。具体表现为:(1)叶绿体膜脂磷脂酰甘油(phosphatidylglycero,PG)分子34∶4PG水解的产物磷脂酸分子34∶4PA的积累速度明显慢于其它磷脂酸分子;(2)磷脂酸分子34∶6PA仅有少量的积累,其可能是由叶绿体膜脂单半乳糖二酰甘油(monogalactosyldiacylglycerol,MGDG)。分子34∶6MGDG和双半乳糖二酰甘油(digalactosyldi-acylglycerol,DGDG)分子34∶6DGDG水解产生,然而这两种糖脂含量明显下降,说明它们有可能还参与了其它的反应。脂类的摩尔百分组成没有剧烈的变化。

This paper employed a sensitive approach based on electrospmy ionization tandem mass spectrometry （ESI-MS/MS） to comprehensively analyze lipid composition changes in response to mechanical wounding in Arabidopsis thaliana. The changes of 6 phosphohpid classes, 2 glycohpid classes, and 3 lysophosphohpid, and 120 lipid molecular species in total depicted the basic tendency of membrane hpids in response to wounding for 0, 15, 30, and 60min in Arabibopsis thaliana. The results showed that wounding can lead to increase phosphatidic acid （PA） and 3 lysophosphohpid 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 hpid 34：4 PC. （ phosphatidylglyceml） 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.