基于代谢组学分析雪茄烟叶晾制时“青斑”组织的代谢差异及形成原因

Metabolomic analysis of metabolic differences and causes of green spot tissue of cigar tobacco during air-curing

为探究雪茄烟叶自然晾制过程中青色斑点(简称“青斑”)形成的生理机制及代谢差异,提高茄衣烟叶外观品质,改进晾制技术,以雪茄烟‘楚雪10号’品种为试验材料,利用高压液相色谱串联质谱(HPLC-MS/MS)非靶向代谢组学技术,分析烟叶“青斑”和正常两组织部位的代谢差异。研究结果表明:“青斑”部位叶绿素和绿原酸含量显著高于正常部位,大量未分解的叶绿素和绿原酸在晾制末期沉积是“青斑”形成的生理基础;“青斑”和正常两组织部位间,酪氨酸代谢、苯丙氨酸代谢和类黄酮生物合成途径具有显著差异;绿原酸和二氢玉米素可作为“青斑”形成过程的化学标记物,晾制过程中可检测其含量高低来监测是否会出现“青斑”;烟叶变黄期晾房湿度骤降且波动过大,可能是形成“青斑”的外部环境因素,建议采用湿度可控晾房晾制并适当提高变黄期湿度。

In order to explore the physiological mechanism and metabolic differences of the green spots("GrS")formed during the natural air-curing process of cigar tobacco,to improve the appearance quality of wrapper tobacco leaves,and to improve the air-curing technology,the cigar tobacco‘Chuxue 10’was used as an experiment materials,using high-pressure liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)non-targeted metabolomics technology to analyze the metabolic differences between the GrS and normal tissues of tobacco leaves.The results of the study showed that the contents of chlorophyll and chlorogenic acid in GrS were significantly higher than those in normal parts,and a large amount of undecomposed chlorophyll and chlorogenic acid deposited at the end of the drying period was the physiological basis for the formation of GrS.There were significant differences in tyrosine metabolism,phenylalanine metabolism and flavonoid biosynthesis between GrS and normal tissues.Chlorogenic acid and dihydrozeatin can be used as chemical markers in the formation process of GrS,and their content can be detected to monitor whether there will be GrS in the process of air drying.During the yellowing period of tobacco leaves,the humidity in the drying room drops suddenly and the extreme difference is too large,which may be the external environmental factor for the formation of GrS.It is recommended to use the humidity controlled drying room and appropriately increase the humidity in the yellowing period.