烤烟成熟期氮代谢及其关键酶活性和相关基因表达分析  

Dynamic analysis of key enzyme activities and gene expression of nitrogen metabolism in flue-cured tobacco at mature stage

作　　者：贾保顺[1] 孙祖正 张锦中[1] 朱学杰 JIA Baoshun;SUN Zuzheng;ZHANG Jinzhong;ZHU Xuejie(Zhoukou Branch of Henan Provincial Tobacco Company,Zhoukou 466000,China;Nanyang Branch of Henan Provincial Tobacco Company,Nanyang 473000,China)

机构地区：[1]河南省烟草公司周口市公司,河南周口466000 [2]河南省烟草公司南阳市公司,河南南阳473000

出　　处：《河南农业大学学报》2020年第4期559-565,共7页Journal of Henan Agricultural University

基　　金：河南省烟草公司驻马店市公司科技计划项目(201741170020071)。

摘　　要：以烤烟品种K 326和NC 71为试验材料,测定分析了烟叶成熟期含氮化合物(叶片NH4^+、可溶性蛋白质、总氮和游离氨基酸)含量和氮代谢关键酶活性,并对其关键酶基因(NtNR,NtGS和NtGOGAT)进行实时荧光定量PCR分析。结果表明在烤烟成熟期,烟叶内总氮、可溶性蛋白质和游离氨基酸含量总体呈逐渐降低的变化趋势。叶片NH4^+呈单峰波动变化,移栽后80 d时其含量达到峰值。从移栽后70 d开始,烟叶谷氨酰胺合成酶(GS)、谷氨酸脱氢酶(GDH)和谷氨酸合成酶(GOGAT)活性逐渐增强,至移栽后80 d其活性达到最高,随后逐渐降低。NtGR基因表达量在成熟期逐渐降低,而NtGS和NtGOGAT基因表达量则呈先升高后降低的变化趋势。硝酸还原酶(NR)对烟叶氮代谢起主要调控作用,GS对调节叶片NH4^+有重要影响。同一生态环境和栽培条件下,NtGS广泛参与烟叶的氮代谢调控,而NtGOGAT起主要协助作用。Using flue-cured tobacco cultivars K 326 and NC 71 as experimental materials,the contents of nitrogen compounds(NH4^+,soluble protein,total nitrogen and free amino acids)and the activities of key enzymes in nitrogen metabolism of flue-cured tobacco leaves at maturity stage were determined and analyzed.The key enzymes genes(NtNR,NtGS and NtGOGAT)were analyzed by real-time quantitative PCR.The results showed that the contents of total nitrogen,soluble protein and free amino acid in flue-cured tobacco decreased gradually at maturity stage.The NH4^+ content in leaves fluctuated with a single peak,reaching a peak at 80 days after transplanting.The activity of glutamine synthetase(GS),glutamate dehydrogenase(GDH)and glutamine oxoglutarate aminotransferase(GOGAT)increased gradually from 70 days after transplanting,and reached the highest level at 80 days after transplanting,and then decreased gradually.The expression of NtGR gene decreased gradually during maturity stage,while the expression of NtGS and NtGOGAT gene increased at first and then decreased.NR played a major role in regulating nitrogen metabolism in tobacco leaves,and GS played an important role in regulating NH4^+ in leaves.Under the same ecological environment and cultivation conditions,NtGS was widely involved in the regulation of nitrogen metabolism in tobacco leaves,and NtGOGAT played a major role in assisting.

关 键 词：烤烟 成熟期 氮代谢 关键酶活性 基因表达 

分 类 号：S572[农业科学—烟草工业]