背景:非靶向代谢组学是一种强大的工具,可提供对代谢物水平的定量变化进行系统了解的策略,特别是当组合不同的代谢组学平台时。香草是世界上最受欢迎的口味之一,源自兰花香草花的腌制豆荚。然而,只有少数研究调查了扁平弧菌的代谢组,并且尚未进行有关叶片的LC-MS或GC-MS代谢组学研究。
目的:研究的目的是全面表征不同器官的代谢组(叶,节间,和气生根)。
方法:使用两个互补平台(GC×GC-MS,LC-QToF-MS),和代谢物鉴定是基于与内部数据库或精选的外部光谱库的比较。
结果:总计,可以确定127种代谢物(置信水平1或2),包括糖,氨基酸,脂肪酸,有机酸,和胺/酰胺,还有次级代谢物,如香草醛相关的代谢物,黄酮类化合物,和萜类化合物.98种代谢物在植物器官之间显示出明显不同的强度。最引人注目的是,类黄酮和香草醛相关代谢物的糖苷在气根中升高,而其O-糖苷形式在叶片和/或节间往往更高。这表明,更多的生物活性糖苷配基可以积累在优选需要的地方,例如用于防御病原体。
结论:从研究中得出的结果大大扩展了有关香草代谢组的知识,为未来研究中更有针对性的研究提供了有价值的基础。例如,对香草植物栽培的优化。
BACKGROUND: Untargeted metabolomics is a powerful tool that provides strategies for gaining a systematic understanding of quantitative changes in the levels of metabolites, especially when combining different metabolomic platforms. Vanilla is one of the world\'s most popular flavors originating from cured pods of the orchid Vanilla planifolia. However, only a few studies have investigated the metabolome of V. planifolia, and no LC-MS or GC-MS metabolomics studies with respect to leaves have been performed.
OBJECTIVE: The aim of the study was to comprehensively characterize the metabolome of different organs (leaves, internodes, and aerial roots) of V. planifolia.
METHODS: Characterization of the metabolome was achieved using two complementary platforms (GC × GC-MS, LC-QToF-MS), and metabolite identification was based on a comparison with in-house databases or curated external spectral libraries.
RESULTS: In total, 127 metabolites could be identified with high certainty (confidence level 1 or 2) including sugars, amino acids, fatty acids, organic acids, and amines/amides but also secondary metabolites such as vanillin-related metabolites, flavonoids, and terpenoids. Ninty-eight metabolites showed significantly different intensities between the plant organs. Most strikingly, aglycons of flavonoids and vanillin-related metabolites were elevated in aerial roots, whereas its O-glycoside forms tended to be higher in leaves and/or internodes. This suggests that the more bioactive aglycones may accumulate where preferably needed, e.g. for defense against pathogens.
CONCLUSIONS: The results derived from the study substantially expand the knowledge regarding the vanilla metabolome forming a valuable basis for more targeted investigations in future studies, e.g. towards an optimization of vanilla plant cultivation.