【摘要】 为分析烟叶在生长过程中的次生代谢物质动态变化特征、相关酶的活性变化规律,以3个烤烟种植试验点的烤烟为研究对象,研究不同叶位烟草叶片多酚类物质含量、抗氧化活性和表达量。结果表明,同一个采样点中,不同叶位烟叶多酚类物质含量表现为上叶位>中叶位>下叶位。不同叶位烟草叶片PAL、PPO、C4H和4CL活性以上叶位最高。通过多酚体外抗氧化测定,表明不同叶位多酚对DPPH和羟基自由基有一定的清除能力。荧光定量PCR检测发现,PAL基因和PPO基因在上叶位中的表达显著高于其他叶位。烤烟生长过程中的次生代谢物质动态变化,相关酶的活性变化及基因表达水平与烟叶成熟度存在一定的关联。更多还原

【Abstract】 Aiming to analyze the dynamic changes of secondary metabolites and related enzymes during tobacco growth, the content, antioxidant activity and expression level of polyphenols in tobacco leaves at different leaf positions were studied in three tobacco planting experimental sites. In the same sampling site, the content of polyphenols in tobacco leaves of different leaf positions showed as follows:upper leaf position>middle leaf position>lower leaf position. The activities of PAL, PPO, C4 H and 4 CL in tobacco leaves at different positions showed that the enzyme activity in the upper leaves was the highest. The antioxidant activity of polyphenols in vitro showed that polyphenols in different leaf positions had certain scavenging ability to DPPH and hydroxyl free radicals. q-PCR analysis showed that the expression of PAL and PPO genes in the upper leaf was significantly higher than that of other leaf positions. Dynamic changes of secondary metabolites, enzyme activity and gene expression levels were correlated with tobacco maturity during the growth of flue-cured tobacco.更多还原