关键词: 烤烟, 糖代谢, 酶活性, 基因表达

Abstract: 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.

Key words: flue-cured tobacco, sugar metabolism, enzyme activity, gene expression