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

The effects of Pb2+ stress on differential metabolites and key pathways in barley grain were investigated by liquid chromatography-tandem mass spectrometry

摘要:

为评估铅（Pb）污染地区对大麦籽粒的影响。本研究采用液相色谱-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P＜0.5，VIP＞1的条件下，正、负离子模式中，铅胁迫大麦与对照组中共筛选出50种差异代谢物（其中上调20种，下调30种），发现铅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。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代谢通路。结果发现，大麦受到铅胁迫后，铅离子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。

Abstract:

To evaluate the effects of lead (Pb) contamination on barley grain. This study used 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. Under the condition of P<0.5, VIP>1, in the positive and negative ion modes, A total of 50 differential metabolites (20 up-regulated and 30 down-regulated) were screened out between lead-stressed and control barley. It was found that lead stress had significant effects on the content of lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds, and organic heterocyclic compounds in barley. Through KEGG functional pathway enrichment analysis, 16 metabolic pathways were screened out, of which 4 metabolic pathways (citric acid cycle, glutathione metabolism, sugar oxide and dicarboxylic acid metabolism, phenylpropane metabolism) were the metabolic pathways that hit the differential metabolites. The results showed that lead ion 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.