Nilsson Anders K, Johansson Oskar N, Fahlberg Per, Steinhart Feray, Gustavsson Mikael B, Ellerström Mats, Andersson Mats X
Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
Phytochemistry. 2014 May;101:65-75. doi: 10.1016/j.phytochem.2014.01.020. Epub 2014 Feb 19.
Plant membranes are composed of a wide array of polar lipids. The functionality of these extends far beyond a pure structural role. Membrane lipids function as enzyme co-factors, establish organelle identity and as substrates for enzymes such as lipases and lipoxygenases. Enzymatic degradation or oxidation (enzymatic or non-enzymatic) of membrane lipids leads to the formation of a diverse group of bioactive compounds. Plant defense reactions provoked by pathogenic microorganisms are often associated with substantial modifications of the lipidome. In this study, we profiled changes in phospholipids during the hypersensitive response triggered by recognition of the bacterial effector protein AvrRpm1 in Arabidopsis thaliana. A simple and robust LC-MS based method for profiling plant lipids was designed to separate all the major species of glycerolipids extracted from Arabidopsis leaf tissue. The method efficiently separated several isobaric and near isobaric lipid species, which otherwise are difficult to quantify in direct infusion based profiling. In addition to the previously reported OPDA-containing galactolipids found to be induced during hypersensitive response in Arabidopsis, three OPDA-containing sulfoquinovosyl diacylglycerol species, one phosphatidylinositol species as well as two acylated OPDA-containing phosphatidylglycerol species were found to accumulate during the hypersensitive response in Arabidopsis. Our study confirms and extends on the notion that the hypersensitive response in Arabidopsis triggers a unique profile of Allene Oxide Synthase dependent oxidation of membrane lipids. Primary targets of this oxidation seem to be uncharged and anionic lipid species.
植物膜由多种极性脂质组成。这些脂质的功能远不止于单纯的结构作用。膜脂作为酶的辅助因子发挥作用，确定细胞器的特性，并作为脂肪酶和脂氧合酶等酶的底物。膜脂的酶促降解或氧化（酶促或非酶促）会导致形成多种生物活性化合物。病原微生物引发的植物防御反应通常与脂质组的显著变化有关。在本研究中，我们分析了拟南芥中由细菌效应蛋白AvrRpm1的识别引发的超敏反应过程中磷脂的变化。设计了一种基于液相色谱 - 质谱的简单且可靠的植物脂质分析方法，用于分离从拟南芥叶组织中提取的所有主要甘油脂质种类。该方法有效地分离了几种等压和近等压脂质种类，否则在基于直接进样的分析中难以定量。除了先前报道的在拟南芥超敏反应期间被诱导的含OPDA的半乳糖脂外，还发现三种含OPDA的磺基喹喔啉二酰基甘油种类、一种磷脂酰肌醇种类以及两种含酰化OPDA的磷脂酰甘油种类在拟南芥超敏反应期间积累。我们的研究证实并扩展了这样一种观点，即拟南芥中的超敏反应会触发膜脂的丙二烯氧化物合酶依赖性氧化的独特谱图。这种氧化的主要靶点似乎是不带电荷的和阴离子脂质种类。
