In this study, we evaluated the potential use of MALDI-TOF MS Profiling for the differentiation of biological samples submitted to different treatments. We compared the bacterium Xanthomonas campestris pv. campestris (Xcc), grown in culture medium and in vivo (recovered from the plant). Plant samples were also analyzed and included explants at different somatic embryogenesis (SE) stages, as well as leaves from Brassica oleracea and Arabidopsis thaliana inoculated with Xcc, at different time points. The results showed that bacteria and highly divergent plant samples, such as those from embryogenic stages, can be unequivocally differentiated and the clustering was in accordance with proteomic analysis performed by 2-DE. These results show an important application of MALDI-TOF MS Profiling to select and prioritize samples to be analyzed prior to more complex approaches including transcriptomics and proteomics. We also show that in plant-pathogen interactions, when more subtle differences are obtained, the main contribution of MALDI-TOF MS Profiling is in the assessment of experimental variability. This is relevant since reproducibility is a challenging issue when dealing with complex experimental conditions such as plant-pathogen interactions. We propose the use of MALDI-TOF MS Profiling to aid researchers in minimizing experimental variability unrelated to the condition being analyzed. SIGNIFICANCE: MALDI-Profiling offers an inexpensive, rapid and reliable approach for investigating the protein profile to assess sample differentiation and experimental variability in microorganisms and plants and can be highly useful to analyze samples prior to more complex and expensive techniques such as proteomics and transcriptomics.

中文翻译：

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MALDI TOF MS分析：在细菌和植物样品分化和生物变异性评估中的应用。

在这项研究中，我们评估了使用MALDI-TOF MS分析技术对提交给不同处理方法的生物样品进行分化的潜在用途。我们比较了Xanthomonas campestris pv细菌。喜树（Xcc），在培养基和体内生长（从植物中回收）。还分析了植物样品，其中包括不同体细胞胚发生（SE）阶段的外植体，以及在不同时间点接种了Xcc的甘蓝和拟南芥的叶片。结果表明，细菌和高度分化的植物样品，例如来自胚胎发生阶段的样品，可以被明确地区分，并且聚类与2-DE进行的蛋白质组学分析一致。这些结果表明，在更复杂的方法（包括转录组学和蛋白质组学）之前，MALDI-TOF MS分析在选择和确定待分析样品的优先次序方面具有重要的应用。我们还表明，在植物与病原体的相互作用中，当获得更细微的差异时，MALDI-TOF MS分析的主要贡献在于评估实验变异性。这很重要，因为在处理复杂的实验条件（例如植物与病原体的相互作用）时，可再现性是一个具有挑战性的问题。我们建议使用MALDI-TOF MS分析来帮助研究人员最大程度地减少与分析条件无关的实验变异性。重要性：MALDI配置文件提供了一种廉价的，