代谢组学辅助的低烟碱烟草CD01及亲本K326烤后烟叶化学成分差异解析OA

[Objective]The study investigates the differences in chemical components between the cured leaves of the low-nicotine tobacco line CD01 and its parental cultivar K326.It aims to clarify the impact of nicotine content variation on secondary metabolism and tobacco qual-ity,thereby providing a theoretical basis for breeding low-nicotine tobacco varieties.[Method]The low-nicotine tobacco line CD01(nicotine content approximately 0.07％)and the conventional cultivar K326 served as experimental materials.Non-targeted metabolomics,combined with quantitative analyses of conventional chemical components,total protein,free amino acids,and volatile aroma compounds,were used to systematically compare the metabolic profiles of the two lines.Sensory evaluation was performed to validate changes in tobacco quality.[Re-sult]Conventional component analysis showed that,compared with K326,CD01 exhibited significantly reduced total alkaloid and nicotine contents,increased potassium content,and no significant difference in total nitrogen.Metabolomic analysis identified 540 differential metabo-lites,with nitrogen heterocycles accounting for the largest proportion.KEGG enrichment analysis indicated that the differential metabolites were mainly enriched in nitrogen-containing pathways,including tryptophan metabolism and phenylpropanoid biosynthesis.CD01 showed un-changed total protein but increased total free amino acids,with asparagine,alanine,valine,and histidine up-regulated and proline down-regu-lated.Volatile aroma analysis revealed that the fatty acid compound methyl palmitate and the carotenoid degradation product megastigmatrien-one were significantly increased in CD01,while neophytadiene and solanone were significantly decreased.Sensory evaluation indicated that CD01 possessed a delicate,soft aroma and achieved a higher total score than K326.[Conclusion]The substantial reduction in nicotine con-tent in CD01 disrupts nitrogen metabolic flux,leading to the accumulation of free amino acids and remodeling of volatile components.The study confirms at the metabolic level that nicotine is a key regulator of tobacco secondary metabolism,and its content variation shapes the u-nique quality characteristics of low-nicotine tobacco.