{"title":"Reducing nitrate and tobacco-specific nitrosamine level in burley tobacco leaves through grafting on flue-cured tobacco rootstock.","authors":"Yuqing Feng, Yuanyuan Zhao, Geng Li, Hongzhi Shi","doi":"10.1002/pld3.536","DOIUrl":null,"url":null,"abstract":"<p><p>Nitrosation of pyridine alkaloids in tobacco generates tobacco-specific nitrosamines (TSNAs), which are notable toxicants in tobacco products and smoke. Burley tobacco, a chloroplast- and nitrogen (N)-deficient phenotype that accumulates high levels of nitrate-nitrogen (NO<sub>3</sub>-N) in its leaves, is particularly susceptible to TSNAs formation. In this study, reciprocal pot and field grafting experiments were conducted using burley tobacco Eyan No.1 and flue-cured tobacco K326 to investigate whether grafting burley tobacco scions on flue-cured tobacco rootstocks could enhance pigment biosynthesis and photosynthesis, while reducing the NO<sub>3</sub>-N level in burley tobacco leaves. Grafting burley tobacco scions on flue-cured tobacco rootstocks significantly increased the total pigment content, photosynthetic rate, biomass, nitrate reductase and glutamine synthetase activities, as well as ammonium-nitrogen (NH<sub>4</sub>-N), total soluble and reducing sugar, and soluble protein levels in burley tobacco leaves compared with burley tobacco self-rooting, while decreasing the NO<sub>3</sub>-N level and nitrate-N to total N ratio. Transcriptomic analysis revealed that grafting resulted in upregulated expression of genes involved in starch, sucrose, porphyrin, chlorophyll, and N metabolism, as well as carbon fixation and carotenoid biosynthesis. The findings suggest that grafting on high N use efficiency rootstock is an exceptionally promising means of decreasing NO<sub>3</sub>-N accumulation by improving photosynthesis and N metabolism in the scion, thereby reducing the levels of harmful TSNAs.</p>","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"7 10","pages":"e536"},"PeriodicalIF":2.3000,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/55/aa/PLD3-7-e536.PMC10568975.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Direct","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1002/pld3.536","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/10/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Nitrosation of pyridine alkaloids in tobacco generates tobacco-specific nitrosamines (TSNAs), which are notable toxicants in tobacco products and smoke. Burley tobacco, a chloroplast- and nitrogen (N)-deficient phenotype that accumulates high levels of nitrate-nitrogen (NO3-N) in its leaves, is particularly susceptible to TSNAs formation. In this study, reciprocal pot and field grafting experiments were conducted using burley tobacco Eyan No.1 and flue-cured tobacco K326 to investigate whether grafting burley tobacco scions on flue-cured tobacco rootstocks could enhance pigment biosynthesis and photosynthesis, while reducing the NO3-N level in burley tobacco leaves. Grafting burley tobacco scions on flue-cured tobacco rootstocks significantly increased the total pigment content, photosynthetic rate, biomass, nitrate reductase and glutamine synthetase activities, as well as ammonium-nitrogen (NH4-N), total soluble and reducing sugar, and soluble protein levels in burley tobacco leaves compared with burley tobacco self-rooting, while decreasing the NO3-N level and nitrate-N to total N ratio. Transcriptomic analysis revealed that grafting resulted in upregulated expression of genes involved in starch, sucrose, porphyrin, chlorophyll, and N metabolism, as well as carbon fixation and carotenoid biosynthesis. The findings suggest that grafting on high N use efficiency rootstock is an exceptionally promising means of decreasing NO3-N accumulation by improving photosynthesis and N metabolism in the scion, thereby reducing the levels of harmful TSNAs.
期刊介绍:
Plant Direct is a monthly, sound science journal for the plant sciences that gives prompt and equal consideration to papers reporting work dealing with a variety of subjects. Topics include but are not limited to genetics, biochemistry, development, cell biology, biotic stress, abiotic stress, genomics, phenomics, bioinformatics, physiology, molecular biology, and evolution. A collaborative journal launched by the American Society of Plant Biologists, the Society for Experimental Biology and Wiley, Plant Direct publishes papers submitted directly to the journal as well as those referred from a select group of the societies’ journals.