烤烟生长过程中多酚类物质及其相关酶活性的变化

摘要

[Objective] In order to define the suitable harvest time of flue-cured tobacco,polyphenols content and its related enzyme activity change of leaves during flue-cured tobacco growth process were studied.[Method] Tobacco leaves of different growing stage from three harvest time treatments (normal,delay 7 d and delayl4 d) were collected to measure the content of polyphenols and activity of polyphenols metabolism related enzyme.[Result] Results showed that topping could great stimulate polyphenols content,especially new chlorogenic acid,chlorogenic acid and rutin,but not including scopoletin.Polyphenols content decreased after topping,and maintained a low level in maturing stage.From normal harvest to delay 14 d,polyphenols content in middle part leaf increased,but decreased in upper part leaf.Except for scopoletin,PAL activity for both middle part led and upper part leaf correlated positively with polyphenols content.PPO activity for both middle part leaf and upper part leaf correlated negatively with polyphenols content.[Conclusion] Polyphenols content was changed regularly with tobacco leaf maturing,and topping could stimulate transitorily polyphenols content,and scopoletin had a different change law from other polyphenols.The content of polyphenols was controlled by the activities of polyphenols related synthesis and degradation enzymes.%[目的]明确烤烟生长过程中叶片多酚类物质含量及其相关酶活性的变化规律,为确定云南产区适熟烟叶物质基础提供依据.[方法]在田间采集不同发育阶段的烟叶,同时在呆收期设定常规呆收和延迟7、14d采收3个处理,跟踪测定了烟叶中主要多酚类物质含量及其代谢相关酶活性,并进行数理统计分析.[结果]打顶措施大幅提升烟叶中多酚含量,其中新绿原酸、绿原酸、芸香苷反应明显,莨菪亭含量不受打顶措施的影响;打顶后烟叶多酚含量逐渐回落至较低水平,并维持到烟叶进入成熟期;随着烟叶成熟度的增加(由常规采收至延迟14 d采收),中部叶多酚总量总体呈上升趋势,上部叶在这段时期呈下降趋势;除莨菪亭外,中部和上部叶PAL活性与其他酚类物质含量均呈正相关;中部和上部叶PPO活性与酚类物质含量均呈负相关.[结论]烟叶中多酚含量随成熟度增加呈规律性变化,打顶可短暂提升烟叶多酚类物质含量,莨菪亭的变化规律不同于其它几类多酚类物质,多酚类物质含量受烟叶中多酚合成和降解酶活性控制.