Research Centre for Plant Metabolomics, Department of Biochemistry, University of Johannesburg, Auckland Park, 2006, South Africa.
Research Centre for Plant Metabolomics, Department of Biochemistry, University of Johannesburg, Auckland Park, 2006, South Africa.
Plant Physiol Biochem. 2020 Nov;156:267-277. doi: 10.1016/j.plaphy.2020.09.006. Epub 2020 Sep 16.
Lipopolysaccharides (LPSs) are microbe-associated molecular pattern molecules (MAMPs) from Gram-negative bacterial pathogens that potentially contain three different MAMPs (the O-polysaccharide chain, the oligosaccharide core and lipid A). LPSs was purified from Burkholderia cepacia, Pseudomonas syringae and Xanthomonas campestris and electrophoretically profiled. Outcomes of the interactions of the three different LPS chemotypes with Arabidopsis thaliana, as reflected in the induced defence metabolites, profiled at 12 h and 24 h post elicitation, were investigated. Plants were pressure-infiltrated with LPS solutions and methanol-based extractions at different time points were performed for untargeted metabolomics using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Multivariate data modelling and chemometric analysis were applied to generate interpretable biochemical information from the multidimensional data sets. The three LPSs triggered differential metabolome changes in the plants as apparent from chromatographically distinct MS chromatograms. Unsupervised and supervised multivariate data models exhibited time- and treatment-related variations, and revealed discriminating metabolite variables. Heat map models comparatively displayed the up-regulated pathways affecting the metabolomes and Venn diagrams indicated up-regulated and shared metabolites among the three LPS treatments. The altered metabolomes reflect the up-regulation of metabolites from not only the glucosinolate pathway, but also from the shikimate-phenylpropanoid-flavonoid -, terpenoid - and indolic/alkaloid pathways, as well as oxygenated fatty acids. Distinct phytochemical profiles, especially at the earlier time point, suggest differences in the perception of the three LPS chemotypes, associated with the molecular patterns within the tripartite lipoglycans.
脂多糖 (LPSs) 是革兰氏阴性细菌病原体的微生物相关分子模式分子 (MAMPs)，可能包含三种不同的 MAMPs（O-多糖链、寡糖核心和脂 A）。从伯克霍尔德氏菌、丁香假单胞菌和野油菜黄单胞菌中纯化 LPSs，并进行电泳分析。研究了三种不同 LPS 化学型与拟南芥相互作用的结果，反映在诱导防御代谢物中，在激发后 12 和 24 小时进行分析。用 LPS 溶液对植物进行加压渗透，并在不同时间点用甲醇提取进行非靶向代谢组学分析，使用超高效液相色谱与四极杆飞行时间质谱联用。应用多变量数据分析模型和化学计量学分析从多维数据集生成可解释的生化信息。三种 LPS 在植物中触发了不同的代谢组变化，这从色谱上明显不同的 MS 色谱图中可以看出。无监督和有监督的多变量数据分析模型表现出时间和处理相关的变化，并揭示了区分代谢物变量。热图模型比较显示了影响代谢组的上调途径，Venn 图表明三种 LPS 处理之间存在上调和共享的代谢物。改变的代谢组反映了不仅来自硫代葡萄糖苷途径，而且来自莽草酸-苯丙素-类黄酮途径、萜类途径和吲哚/生物碱途径以及氧化脂肪酸的代谢物的上调。独特的植物化学特征，特别是在较早的时间点，表明三种 LPS 化学型的感知存在差异，这与三部分糖脂中的分子模式有关。
