应用液质联用代谢组学技术探究Pb2+胁迫对大麦籽粒中差异代谢物及关键通路的影响

Liquid Chromatography-mass Spectrometry Investigation of Differential Metabolites and Key Pathways in Barley Grains under Pb2+ Stress

摘要:

为评估铅（Pb2+）污染对大麦籽粒的影响。该研究应用液相色谱-质谱联用（LC-MS）代谢组学技术，结合主成分分析（PCA）、偏最小二乘-判别分析（PLS-DA）等多元统计学方法，在正、负离子模式中，将Pb2+胁迫大麦籽粒（GS1600）与对照组（GSCK）中共筛选出50种差异代谢物。研究发现：Pb2+胁迫对大麦中的脂质和类脂分子、有机酸及衍生物、有机氧化合物、有机杂环化合物含量变化影响显著。并通过KEGG功能通路富集分析，筛选出16条代谢通路，其中4条代谢通路（柠檬酸循环、谷胱甘肽代谢、糖氧化物和二羧酸代谢、苯丙烷代谢）为命中差异代谢物的关键代谢通路。结果表明，大麦受到胁迫后，Pb2+通过影响氨基酸代谢、碳水化合物代谢、辅因子和维生素的代谢以及其他次生代谢产物的生物合成对大麦中脂质和类脂分子、苯环型化合物及有机氧化合物等代谢物产生显著影响。说明Pb2+胁迫会对大麦籽粒的营养价值和风味品质造成一定的影响。

Abstract:

Liquid chromatography-mass spectrometry (LC-MS) metabolomics technology combined with principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and other multivariate statistical methods were used to evaluate the effects of lead (Pb2+) contamination on barley grains. In positive and negative ion modes, 50 differential metabolites were identified from Pb2+ stressed barley grain plants (GS1600) and control grains (GSCK). The results showed that Pb2+ stress significantly affected the amount of lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds, and organic heterocyclic compounds in barley. Through KEGG pathway enrichment analysis, 16 metabolic pathways were identified, of which five metabolic pathways (citric acid cycle, glutathione metabolism, sugar oxidation, dicarboxylic acid metabolism, and phenylpropanoid metabolism) were the key metabolic pathways used to produce differential metabolites. The results showed that Pb2+ significantly affected lipids and lipid-like molecules, benzene ring compounds, and organic oxygen compounds in barley by affecting amino acid metabolism, carbohydrate metabolism, cofactor and vitamin metabolism, and biosynthesis of other secondary metabolites after stress. These results indicated that Pb2+ stress could affect the nutritional value and flavor quality of barley grains.