Casasoli Manuela, Spadoni Sara, Lilley Kathryn S, Cervone Felice, De Lorenzo Giulia, Mattei Benedetta
Dipartimento di Biologia Vegetale, University of Rome La Sapienza, Rome, Italy.
Proteomics. 2008 Mar;8(5):1042-54. doi: 10.1002/pmic.200700523.
Oligogalacturonides (OGs) are elicitors of plant defence responses released from the homogalacturonan of the plant cell wall during the attack by pathogenic micro-organisms. The signalling pathway mediated by OGs remains poorly understood, and no proteins involved in their signal perception and transduction have yet been identified. In order to shed light into the molecular pathways regulated by OGs, a differential proteomic analysis has been carried out in Arabidopsis. Proteins from the apoplastic compartment were isolated and their expression compared between control and OG-treated seedlings. 2-D gels and difference in gel electrophoresis (DIGE) techniques were used to compare control and treated proteomes in the same gel. The analysis of subcellular proteomes from seedlings allowed the identification of novel and low abundance proteins that otherwise remain masked when total cellular extracts are investigated. The DIGE technique showed to be a powerful tool to overcome the high interexperiment variation of 2-D gels. Differentially expressed apoplastic proteins were identified by MS and included proteins putatively involved in recognition as well as proteins whose PTMs are regulated by OGs. Our findings underscore the importance of cell wall as a source of molecules playing a role in the perception of pathogens and provide candidate proteins involved in the response to OGs.
寡聚半乳糖醛酸苷（OGs）是植物细胞壁同型半乳糖醛酸聚糖在病原微生物侵袭时释放的植物防御反应激发子。OGs介导的信号通路仍知之甚少，尚未鉴定出参与其信号感知和转导的蛋白质。为了阐明OGs调控的分子途径，在拟南芥中进行了差异蛋白质组学分析。分离了质外体区室中的蛋白质，并比较了对照幼苗和经OG处理的幼苗中它们的表达。二维凝胶电泳和差异凝胶电泳（DIGE）技术用于在同一凝胶中比较对照和处理后的蛋白质组。对幼苗亚细胞蛋白质组的分析使得能够鉴定出新型的低丰度蛋白质，而当研究总细胞提取物时，这些蛋白质会被掩盖。DIGE技术被证明是克服二维凝胶高实验间差异的有力工具。通过质谱鉴定了差异表达的质外体蛋白，包括可能参与识别的蛋白质以及其翻译后修饰受OGs调控的蛋白质。我们的研究结果强调了细胞壁作为在病原体感知中起作用的分子来源的重要性，并提供了参与对OGs反应的候选蛋白质。
