The Influence Of Nitrogen Application On Enzyme Activity And Its Output In Flue-cured Tobacco Carbon And Nitrogen Metabolism Pathway

Tobacco is an important economic crop.Its yield and quality are closely related to the carbon and nitrogen metabolism.Fertilization is the key to the flue-cured tobacco production cultivation measures.In order to explore the influence about nitrogen application rat to flue-cured tobacco of carbon and nitrogen metabolism,this research sets up the field trials in luzhou smoke zone.It analyzes the agronomic characters,economic characters,roast tobacco after conventional chemical composition,the activity of key enzyme and gene expression in the process of carbon and nitrogen metabolism in the different nitrogen levels on the flue-cured tobacco introduced.cultivation variety Yun 87 and K326 agronomic characters.The main research results are as follows:1?Nitrogen levels are obvious effects on tobacco agronomic characters.With the increase of n application rate,plant height,stem circumference of tobacco plant,pitch are increase and in the same nitrogen level,Yun 87 performed better K3262?N application rate have a significant impact on flue-cured tobacco key enzyme activity,metabolic product,the key enzyme gene expression in the process of carbon and nitrogen metabolism.Overall trend,sucrose synthase and sucrose phosphate synthase,glutamine synthetase,nitrate reductase,glutamate synthetase and glutamate dehydrogenase are increased with the increase of n application rate.Compared the two varieties,Yun 87 related enzyme is activity than K326 at late stages of development.In the early of growth,high level nitrogen treatment's invertase and amylase is activity than low level nitrogen treatment and the opposite in the late of growth,the Yun 87 enzyme activity than K326.In terms of metabolites,under low nitrogen level,The total sugar,reducing sugar and starch of K326 is higher than the Yun 87,and the opposite in high nitrogen and middle nitrogen levels.Free amino acid and total nitrogen is down with the leaf growth,while the content of nicotine rises,the content of soluble protein is to the peak in the budding period.The expression of carbon and nitrogen metabolism key enzyme genes are also affected by n application rate,but not obvious regularity in each time.3?Different nitrogen levels influence on roast tobacco leaf chemical components.The parts have different chemical component content,and the upper lobe and middle lobe each chemical composition content is more than the lower lobe.4?The stepwise regression between carbon and nitrogen metabolism of key enzyme activity and roast tobacco leaf chemical components showed that:Glutamine synthetase,glutamate synthetase and glutamate dehydrogenase,sucrose phosphate synthase and invertase larger influence on roast tobacco leaf chemical components,after transplanting 47 days and 66 days.The amylase,glutamine synthetase,glutamate synthetase and sucrose phosphate synthase and invertase are greater effects on roast tobacco leaf chemical components after transplanting 80 days5.The stepwise regression between carbon and nitrogen metabolism of key enzyme gene expression and roast tobacco leaf chemical components showed that:In different growth period,the correlation expression of these genes and the chemical composition performance not the same.Overall,the content of soluble sugars relate obviously with carbon metabolism gene expression,and the content of nitrogen compounds have larger related with nitrogen metabolism gene expression.6.In terms of economic characters,7kg/mu,8kg/mu pure nitrogen treatment has the highest yield,and 7kg/mu pure nitrogen treatment is the largest,in the proportion of superior tobacco.In general,n application at 7 kg/mu,grew more moderate,and quality of tobacco leaf and economic characters,Yun87 is better than K326.