基于代谢组学分析明火熏烤烟叶的代谢差异及形成机制

Metabolomic Analysis of Metabolic Differences and Formation Mechanisms in Open Fire-cured Tobacco Leaves

【目的】运用代谢组学技术分析明火熏烤烟叶的代谢差异及其形成机制。【方法】以烤烟品种K326为试验材料,进行明火熏烤(X)和常规烘烤(CK)对比试验,利用代谢组学技术分析2种调制方法的代谢差异,并探讨其形成机制。【结果】KEGG富集结果表明:在X-38 vs CK-38比较组中,亚油酸代谢和植物激素信号转导是富集最显著的2条通路;在X-42 vs CK-42比较组中,糖酵解/糖异生和氨基酸的生物合成是富集最显著的2条通路;在CK-42 vs CK-38比较组和X-42 vs X-38比较组中,亚油酸代谢和核苷酸代谢是富集最显著的2条通路。在4个比较组中,上调表达的代谢物包括游离脂肪酸、氨基酸及其衍生物、酚酸类、糖类、有机酸、生物碱、核苷酸及其衍生物等。【结论】明火熏烤烟叶的差异代谢物包含大量酸性代谢物。形成差异的原因是明火熏烤使烟叶额外受到烟雾和光热辐射胁迫,促使其形成更多的代谢物。

[Purpose]To analyze the metabolic differences and formation mechanisms in open firecured tobacco leaves by metabolomics techniques.[Methods]Tobacco cultivar K326 was used as the test material for a comparative study between open fire-curing(X)and conventional curing(CK).Metabolomic techniques were employed to analyze the metabolic differences between the two curing methods and to explore their formation mechanisms.[Results]KEGG enrichment results indicated that:in the X-38 vs CK-38 comparison groups,linoleic acid metabolism and plant hormone signal transduction were the two most significantly enriched pathways;in the X-42 vs CK-42 comparison groups,glycolysis/gluconeogenesis and amino acid biosynthesis were the two most significantly enriched pathways;in the CK-42 vs CK-38 and X-42 vs X-38 comparison groups,linoleic acid metabolism and nucleotide metabolism were the two most significantly enriched pathways.The upregulated metabolites in all four comparison groups included free fatty acids,amino acids and their derivatives,phenolic acids,sugars,organic acids,alkaloids,nucleotides and their derivatives.[Conclusion]The differential metabolites in open fire-cured tobacco leaves include a large number of acidic metabolites.The formation of these differences is due to additional environmental stresses such as smoke and thermal radiation experienced during open fire-curing,which lead to the production of more metabolites in open fire-cured tobacco leaves.