烟叶发育过程中糖代谢相关酶活性及基因的表达分析

为了探究烟叶发育过程中糖代谢特性与相关酶活性及基因表达的关系,以烤烟品种秦烟96为材料,测定烟叶发育过程中葡萄糖、果糖、蔗糖、还原糖和可溶性总糖含量变化,分析糖代谢关键酶活性及基因表达水平。结果表明,烟叶移栽后65～115 d的发育过程中,葡萄糖、果糖、还原糖和可溶性总糖含量呈先上升后下降的趋势,当烟叶成熟(移栽后95 d)时,各可溶性糖(蔗糖除外)含量达到峰值;蔗糖含量呈双峰波动变化,烟叶成熟时蔗糖含量最低;烟叶打顶至适熟阶段,SPS和AI酶活性对烟叶中可溶性糖的积累贡献最大,当烟叶由适熟至过熟时,AI主要参与烟叶的糖代谢调控,而SS和SPS则对蔗糖的积累起重要作用; Nt INV基因在烟叶打顶至适熟阶段对烟叶糖代谢调控作用较大,而Nt SS和Nt SPS基因则在烟叶适熟至过熟阶段对烟叶糖代谢起主要的调控作用;糖代谢相关基因通过分子层面调控相关酶活性进而调控烟叶的糖代谢活动。

Dynamic Analysis of Enzyme Activities and Expression of Genes Related to Sugar Metabolism During the Development of Tobacco

In order to explore the relationship between sugar metabolism with related enzyme activities and gene expression during the development of tobacco leaves, the contents of glucose, fructose, sucrose, reducing sugar and total soluble sugar in the development of tobacco leaves were measured; and the key enzyme activities and gene expression levels related were analyzed with the tobacco variety Qinyan 96 as material. The results showed that the contents of glucose, fructose, reducing sugar and total soluble sugar increased first and then decreased during the development of tobacco from 65 d to 115 d after transplanting. When the tobacco leaves matured (95 d after transplanting), the contents of soluble sugar (except sucrose) reached to peak value. The content of sucrose showed a bimodal fluctuation and the tobacco had the lowest sucrose content at maturity. During the topping to proper maturity of tobacco leaves, SPS and AI enzyme activities contributed the most to the accumulation of soluble sugar in tobacco leaves. When tobacco leaves were from ripe to overripe, AI was mainly involved in the regulation of sugar metabolism in tobacco leaves, while SS and SPS played important roles in the accumulation of sucrose. NtINV had a greater regulation on tobacco sugar metabolism in the stage from topping to maturity, while NtSS and NtSPS played major roles in regulating sugar metabolism in tobacco leaves from proper maturity to overripe. Sugar metabolism related genes regulated the activity of related enzymes through the molecular level and then regulated the sugar metabolism of tobacco leaves.