基于代谢组学研究栽培基质对铁皮石斛有效成分的影响机理

In recent years, the planting industry of Dendrobium officinale with soilless culture mode has been developing rapidly. However, the research on the optimal redeployment of cultivation substrate often relies on the evaluation of plant growth, which is lack of in-depth study on the mechanism of effective components of Dendrobium officinale influenced by the substrate. As Dendrobium officinale cultivated by different substrates would have different responses and changes in its vivo metabolism, this project is thus conducted based on metabolomics and chemometrics. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are used to detect the effective components of Dendrobium officinale. The strategies of population analysis and multi-objective optimization are used to develop variable selection methods which consider the synergic effect among variables, and data fusion methods are also developed to aggregate GC-MS and LC-MS metabolites information. It aims to screen the marker metabolites between different groups of substrates based on the ideas of multi-method, multi-model, multi-objective and multi-data. The marker metabolites are then combined with physicochemical properties of substrate through correlation analysis, in order to identify the most relevant physicochemical indicators, and reveal the metabolic pathways of marker metabolite and the mechanism of effective components of Dendrobium officinale impacted by the physicochemical properties of substrate. The research results would provide a theoretical basis of the redeployment of cultivation substrate for the production of "high yield" "high quality" of Dendrobium officinale. It contributes to better promote the standardization of Dendrobium officinale planting based on soilless culture. Moreover, the development of variable selection and data fusion methods can further improve and develop the metabolomics research, which provides the basis for its application.

近年来，无土栽培人工种植模式使铁皮石斛产业得到了迅速发展。然而，栽培基质的优化配置研究往往局限在植物长势评价上，在栽培基质对铁皮石斛有效成分的影响机理上缺乏深入研究。不同基质环境下栽培铁皮石斛时其体内代谢有不同响应与变化，本课题基于代谢组学和化学计量学，气相液相色谱与质谱联用仪器分析铁皮石斛有效成分，基于集群分析和多目标优化策略，考虑变量之间的协同作用，发展变量选择方法，同时建立气质液质数据的融合方法，基于多方法、多模型、多目标、多数据来筛选不同基质间的差异性代谢产物。继而将差异性代谢产物与基质理化性质进行相关性分析，明确影响有效成分较大的相关理化指标，揭示其影响代谢的机理及分析相关代谢通路。研究成果可为筛选优质、高产的铁皮石斛栽培基质提供理论基础，有助于铁皮石斛人工种植的标准化。同时，所发展的变量选择及数据融合方法将进一步完善和发展代谢组学方法研究，为其在应用研究中提供方法依据。

无土栽培人工种植铁皮石斛关键在栽培基质的选择上，研究栽培基质对铁皮石斛有效成分的影响有助于优选良好的基质。本项目基于代谢组学技术结合化学计量学方法对不同基质栽培的铁皮石斛的有效成分进行了分析，初步探讨了基质影响铁皮石斛有效成分的机理。首先系统性分析和总结了近二十年来已发表的变量选择方法，基于模型集群分析发展了一种应用于代谢组学差异性代谢物筛选的迭代性揭示有信息代谢物法(RIMI)方法；其次对松树皮、椰块、松树皮：椰块=1:1等基质栽培足一年的铁皮石斛鲜茎条分别采用液相色谱质谱联用（LC-MS）和气相色谱质谱联用（GC-MS）分析其代谢物，通过建立的代谢物测定方法，LC-MS一共测出了529个代谢物，GC-MS一共测出了67个代谢物；基于所测定的代谢物数据，结合变量选择方法筛选了不同基质之间的差异性代谢物，同时探讨了LC-MS与GC-MS数据的融合分析，从低层次和中层次两个方面对数据进行了融合并进行了差异性代谢物的筛选，通过KEGG通路富集找出了显著调控代谢产物的相关生物合成途径。采用皮尔逊分析法探讨了主要有效成分与基质的理化性质指标的相关性，根据结果初步推断影响铁皮石斛有效成分较大的理化指标可能为硝态氮和铵态氮。本项目建立的方法和得出的数据结果对于铁皮石斛有效成分研究、栽培基质的选择以及代谢组学方法数据处理等研究提供了重要基础。