N. glauca, N. langsdorffii, their tumorous amphidiploid hybrid and the non-tumorous mutant hybrid were used as a model system to identify factors causing genetic tumors. The genetic tumors showed a shooty morphology and Richmond-Lang effect (senescence retarding effect of cytokinin) in vivo, suggesting that these tumors may contain an elevated level of cytokinin. This was supported by both cytokinin measurement which was higher cytokinin in tumors than in other tissues and in vitro leaf disc culture experiments in which the shooty morphology of tumorous hybrids was not easily altered by treatments with auxin and/or cytokinin. Increases of auxin up to 12 mg/l did not alter the shooty morphology of the callus. This same auxin treatment applied to the parental species only induced root formation. Leaf discs of the non-tumorous mutant developed small shoot-forming teratomas when cultured on 0.8-1.0 mg/l cytokinin. Furthermore, transformation of leaf discs of the non-tumorous mutant with an Agrobacterium tumefaciens strain carrying only the cytokinin biosynthetic gene produced similar shooty tumors. Therefore, the mutant can be restored to a shooty tumorous phenotype either by the addition of exogenous cytokinin, or by increasing the endogenous cytokinin level through transformation with a gene encoding cytokinin biosynthesis. These results when taken together support the conclusion that a hormone imbalance is the main cause of genetic tumor formation, and that an increase in the cytokinin level more than a change in auxin level is the cause of the hormone imbalance.

Abstract Growth and development processes of a tobacco plant affect the chemical composition of the leaf and therefore the usability of the leaf. Growth starts with the initial stages of germination and development stops with the cured leaf. Most tobacco seed will germinate in the dark and the first seeds to germinate from a seed lot tend to produce larger plants for transplant and harvest. Nicotine is found in mature seed and increased rate of germination increases rate of nicotine accumulation in the young seedling. Carbon / nitrogen balance in the leaf is important for leaf usability and is influenced by available soil water and soil nitrogen. Oriental leaf is produced typically with limited water and nitrogen supply and the leaf contains large amounts of carbohydrates and ether solubles but small amounts of nitrogenous substances. Cigar filler tobacco is grown on soils with a plentiful supply of soil water and soil nitrogen and the leaf contains large amounts of nitrogenous substances. Intermediate to these tobacco types is flue-cured tobacco which is grown with limited soil nirogen but adequate water and the leaf is relatively thin with high carbohydrate content. Maximum rate of leaf expansion is achieved early in development of a leaf. In flue-cured tobacco phosphorus and potassium concentrations remain constant during growth, whereas nitrogen, calcium and magnesium concentrations decrease. In Oriental tobacco the concentrations of nitrogen, phosphorus, potassium and calcium decrease during the growing season. However, Burley tobacco accumulates relatively greater amounts of nitrogen, phosphorus and potassium during the first half of the growing season relative to dry matter accumulation. Maximum growth per unit leaf weight occurs 14 to 21 days after transplanting, whereas maximum dry matter accumulation per day occurs 50 to 55 days after transplanting. Leaf development including senescence is controlled genetically and decreased chlorophyll and protein and increased nicotine contents are important changes associated with leaf senescence. Maximum nicotine content of leaf occurs at successively higher stalk positions as the plant matures.

Abstract Quality tobacco leaf comes from plants grown with balanced mineral nutrition. The “structural nutrients” (carbon, hydrogen and oxygen) are approximately 90 % of the dry weight of cured leaf but are of little economic concern. The macronutrients (nitrogen, phosphorus, potassium, calcium, magnesium and sulfur) and the micronutrients (boron, chlorine, copper, iron, manganese, molybdenum and zinc) are of great economic concern and adequate amounts in the soil are essential for production of quality tobacco leaf. Nitrogen, phosphorus, potassium and magnesium are mobile within the plant and deficiency symptoms are observed first in the lower leaves and later in the upper leaves. Deficiency symptoms of the immobile nutrients calcium, boron, manganese, sulfur and iron are observed first on the upper leaves or terminal bud. Of all the mineral nutrients nitrogen has the greatest effect on shoot and root weight. As available nitrogen increases leaf nicotine increases and reducing sugars decrease; thus the sugar:nicotine ratio decreases dramatically. There is a positive relationship between amount of reduced nitrogen and reduced sulfur in the plant and this interaction is important as most of the reduced nitrogen and sulfur are utilized in protein synthesis. Total uptake of potassium is greater than for any other mineral. Because of the immobility of calcium and boron, deficiency of these nutrients results in physiological decapitation (topping) and consequently increased nicotine content of leaves. Excessive amounts of nutrients can also produce some problems. Excessive nitrogen increases yield but it also increases the incidence of disease, delays flowering and leaf ripening, and lowers leaf quality. Excessive addition of lime causes a basic soil pH which increases disease incidence and limits availability of phosphorus, iron, manganese and zinc. Excessive chlorine increases the hygroscopic property of the leaf and reduces burn rate. Soil applied magnesium oxide may reduce potassium absorption and therefore reduce burn rate.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRoles of tobacco cellulose, sugars, and chlorogenic acid as precursors to catechol in cigarette smokeSteven G. Carmella, Stephen S. Hecht, T. C. Tso, and Dietrich HoffmannCite this: J. Agric. Food Chem. 1984, 32, 2, 267–273Publication Date (Print):March 1, 1984Publication History Published online1 May 2002Published inissue 1 March 1984https://doi.org/10.1021/jf00122a023Request reuse permissionsArticle Views241Altmetric-Citations33LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (924 KB) Get e-Alertsclose Get e-Alerts

AbstractLeaves from 8 stalk positions from four Burley tobaccos, the cultivars Burley 21, Ky 14 and Ky 12 and one breeding line of low-alkaloid Burley 21 (LA Burley 21), were tested in this study. A total of 116 variables, including leaf and smoke characteristics, were determined by collaborating scientists using established methods. Simple correlations and multiple regressions among selected variables were determined to examine the relationship among these variables. Generally, Burley tobaccos do not differ from bright tobaccos, in that the nitrogenous fractions and combustibility appear to be the major factors affecting nicotine and dry TPM (total particulate matter) delivery as well as other major smoke constituents. Stalk position and varieties also demonstrated significant differences in nicotine and dry TPM delivery. Benzo[a]pyrene content, however, did not show significant differences among these experimental Burley tobaccos or stalk positions.

ABSTRACTTobacco leaf proteins are well balanced, containing high levels of essential amino acids. This communication reports the content of soluble leaf protein during different stages of development, and its quality as predicted by chemical analysis and confirmed by biological evaluation. Results show tobacco leaf protein are at the top of the plant protein range in nutritive quality and thus could provide viable food by‐products from the HLC process. Both Fl protein and soluble leaf proteins could be excellent supplements for cereal diets consumed by world populations.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical studies on tobacco smoke. 63. The fate of nicotine during pyrolysis and in a burning cigaretIrwin Schmeltz, Alvin Wenger, Dietrich Hoffmann, and T. C. TsoCite this: J. Agric. Food Chem. 1979, 27, 3, 602–608Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 May 1979https://pubs.acs.org/doi/10.1021/jf60223a044https://doi.org/10.1021/jf60223a044research-articleACS PublicationsRequest reuse permissionsArticle Views321Altmetric-Citations40LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical studies on tobacco smoke. 53. Use of radioactive tobacco isolates for studying the formation of smoke componentsIrwin Schmeltz, Alvin Wenger, Dietrich Hoffmann, and T. C. TsoCite this: J. Agric. Food Chem. 1978, 26, 1, 234–239Publication Date (Print):January 1, 1978Publication History Published online1 May 2002Published inissue 1 January 1978https://pubs.acs.org/doi/10.1021/jf60215a023https://doi.org/10.1021/jf60215a023research-articleACS PublicationsRequest reuse permissionsArticle Views73Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

AbstractCured leaves from eight stalk positions of three varieties and one breeding line of flue‐cured tobacco (Nicotiana labacum L.) were analyzed for fatty acid content and lipid residues. The higher fatty acids with 14 to 18 carbons were determined. The varieties analyzed were ‘Coker 139,’ ‘SC‐58,’ ‘NC‐95,’ and a breeding line ‘LN‐38.’ These varieties differed in alkaloid content and other physical and chemical characteristics. Leaves from SC‐58 and LN‐38 had the highest lipid residue. For all varieties lipid residues were lowest in leaves from the bottom stalk position and next lowest in leaves at the top position. LN‐38 had the highest total fatty acid content of any of the varieties. All varieties except Coker 139 yielded the highest total fatty acid content in leaves at the second stalk position. Also, the proportion of the unsaturated acid 18:3 was highest at position 2 in all varieties and decreased toward the top of the plant.

Tobacco plants (Nicotiana tabacum L.) have served as valuable subjects in many phases of pioneering research. The best known contributions are mineral nutrition, day length, virus and nitrogen metabolism. Tobacco is probably the most frequently used plant in the study of mineral nutrition. Elements can hardly be classified as essential or nonessential, as in the past .. The division into groups of major and minor, primary and secondary, and macroand micro-elements is also arbitrary. Current interest in the production of the tobacco crop in general, and in the study of leaf composition in particular, make it desirable to review the accumulated information. Here I attempt to summarize and examine publications related to microelements and some secondary elements in tobacco, covering a period of nearly 30 years from 1935 to 1964. A few papers of special interest published prior to 1935 are also included. Occasionally, information from studies on other crops is cited in view of its general academic interest and its special value in tobacco research. Elements included are: Aluminum (AI), Arsenic (As), Barium (Ba), Beryllium (Be), Boron (B), Cesium (Cs), Chlorine (Cl), Chromium (Cr), Cobalt (Co), Copper (Cu), Fluorine (F), Gold (Au), Iodine (I), Iron (Fe), Lead (Pb), Lithium (Li), Magnesium (Mg), Manganese (Mn), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Platinum (Pt), Polonium (Po), Radium (Ra), Rubidium (Rb), Selenium (Se), Silicon (Si), Silver (Ag), Sodium (Na), Strontium (Sr), Sulfur (S), Thallium (TI), Tin (Sn), Titanium (Ti), Uranium (U), Vanadium (V), and Zinc (Zn). No attempt is made to include all publications under the subject matter; in fact, some papers were eliminated intentionally to avoid duplication. A bibliography published in 1934 covering literature citations for the years 1921-33 on antimony, bismuth, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, thallium, tin, and zinc, may be consulted for additional information (Heffer and Sons, 1934). Omission of other micro·

It is desirable and necessary to reexamine the in- fluences of stock andl scion oIn alkaloid synthesis and transformation using plants which behave differently witlh respect to alkaloid formation (4).Experiments were conducted in the greenhouse for 3 years in an attempt to separate the effects of root, or stock, from those of the top, or scioIn, on alkaloid synthesis and transformation.Some of the grafting combinations reported in this paper resenmbled those prepared pre- viously by Dawson (2), but plants witlh various de- grees of ability in alkaloid synthesis were included in this study. Materials and MethodsThe following plants were used in these experiments: Lycopersicon esciileni turnl Mill cv.Rutgers (Tom) ; Nicotiana tabacuntii L. cv.Maryland Robinson Medium Broadleaf tobacco, a strain homozygous for nornicotine production (MAd) N. tabacumt cv.Swarr- Hibshman Pennsylvania cigar tobacco (SH); N. tabacntiii L.. cv.Baur, a low nicotine tobacco; N. glauica Grah.(Gla) ; and N. glutinosa L. (Glut)

In the preceding papers (7, 8) of this series we presented the effects of certain mineral deficiency on the organic constituents of tobacco plants. Changes in the organic composition were associated with the development of typical symptoms resulting from an abnormal supply of a specific mineral. Mineral deficiency symptoms, in general, appear initially in a localized area and are very mild. They gradually extend to other portions of the plant and cause further characteristic effects. The severity of the symptoms increases with age and development of plants. In the case of calcium or boron deficiency, initial symptoms appear at the tip of a tobacco plant. Further abnormalities or symptoms gradually advance toward the midd(le portion and finally to the whole plant if the specific nutrient is withdrawn at an early stage of the plant growth. In tobacco plants, calcium or boron deficiency causes, in addition to other symptoms, natural decapitation which is physically similar but physiologically different from manual topping in tobacco cultivation. The present and following reports (in preparation) provide data on the corresponding changes in organic constituents including alkaloids, sugars, organic acids, andl amino acids relating to the gradual development of Caor B-deficiency svmptoms. In this paper results are reported on the plant growth and the alkaloid content in the leaves at various degrees of severity of deficiency symptoms and at different stalk positions.

The F1 hybrid of Nicotiana glauca Grah. and N. langsdorffii Weinm. is well known for its spontaneous tumor-producing ability. Most investigations concerning plant tumors are in the field of genetics or cytology (2,4,6); a few deal with the free amino acid levels of N. glauca, N. langsdorffii and their hybrid (1, 3, 8). However, no references are available on the general chemical composition of the important organic constituent of the plants and their tumorous and visibly non-tumorous tissues. Anders and Vester (1) and Vester and Andrews (8) suggested that the abnormally high free amino acid content in the hybrid plant is connected with the spontaneous formation of tumors. Hagen and Gunckel (3) reported that gamma irradiation caused the leaf abnormalities of the parent species and their hybrid and a concomitant increase in the free amino acid content of these leaves. In this paper we report investigation on the chemical composition of alkaloids, sugars, organic acids. and free amino acids in N. glauca, and N. langsdorffii, and in the tumorous and visibly non-tumorous tissues obtained from F1 (N. glauca X N. langsdorffii) plants at different anatomical locations, in different culture media, and at various stages of plant development.

THE F1 hybrid of N. glauca Grah. and N. langsdorffii Weinm. is well known for its spontaneous tumour-producing ability. Certain potential animal-tumour inhibitors appeared to stimulate the growth of this plant tumour when applied in an amount below the level of inhibiting dosage. Results from chemical investigations on several classes of organic constituents in newly formed tumours from control and treated plants also showed effects of such positive stimulation.

The incorporation of H3 in alkaloid biosynthesis was studied by growing Nicotiana rustica var. brasilia plants in tritiated water. The rate of H3 incorporation was very fast in the first 2.5 hr., after which it was much slower for the remainder of the 70-hr. experiment. The relative rate of incorporation of H3 in different classes of organic compounds was similar to that of C14 from C14O2, except that incorporation of H3 into the alkaloids was much more rapid. H3 activity was detected in tobacco alkaloids 30 min. after a 1-min. exposure, whereas C14 incorporation into the alkaloids was not detected 30 min. after 60 min. exposure.