Life Sciences Commons^™

Development And Functional Analysis Of Novel Genetic Promoters Using Dna Shuffling, Hybridization And A Combination Thereof, Rajiv Ranjan, Sunita Patro, Bhubaneswar Pradhan, Alok Kumar, Indu B. Maiti, Nrisingha Dey

Kentucky Tobacco Research and Development Center Faculty Publications

BACKGROUND: Development of novel synthetic promoters with enhanced regulatory activity is of great value for a diverse range of plant biotechnology applications.

METHODOLOGY: Using the Figwort mosaic virus full-length transcript promoter (F) and the sub-genomic transcript promoter (FS) sequences, we generated two single shuffled promoter libraries (LssF and LssFS), two multiple shuffled promoter libraries (LmsFS-F and LmsF-FS), two hybrid promoters (FuasFScp and FSuasFcp) and two hybrid-shuffled promoter libraries (LhsFuasFScp and LhsFSuasFcp). Transient expression activities of approximately 50 shuffled promoter clones from each of these libraries were assayed in tobacco (Nicotiana tabacum cv. Xanthi) protoplasts. It was observed that most …

Alteration Of Tobacco Alkaloid Content Through Modification Of Specific Cytochrome P450 Genes, Ralph E. Dewey, Balaz Siminszky, Steven W. Bowen, Lily Gavilano

Plant and Soil Sciences Faculty Patents

Compositions and methods for reducing the level of nornicotine and N′-nitrosonornicotine (NNN) in Nicotiana plants and plant parts thereof are provided. The compositions comprise isolated polynucleotides and polypeptides for cytochrome P450s that are involved in the metabolic conversion of nicotine to nornicotine in these plants. Expression cassettes, vectors, plants, and plant parts thereof comprising inhibitory sequences that target expression or function of the disclosed cytochrome P450 polypeptides are also provided. Methods for the use of these novel sequences to inhibit expression or function of cytochrome P450 polypeptides involved in this metabolic conversion are also provided. The methods find use in …

Effect Of Tray Type And Tray Covering On Wicking Speed, Germination, And Spiral Rooting Of Tobacco, William A. Bailey, Bill Pitt

Plant and Soil Sciences Research Report

Poor tray wicking and spiral rooting continue to be recurring concerns in tobacco float systems. Poor wicking of trays can usually be attributed to old media or media that was improperly stored for extended periods of time. Tray design may also influence speed of wicking. The clay-based pelleting materials used to coat tobacco seeds are thought to cause damage to the emerging root radical under certain conditions, leading to an increased incidence of spiral root. Practices that change the microenvironment at the top of the cell area surrounding the seed may reduce spiral rooting by altering the breakdown of the …

Tillage And Subsoiling Effects On Soil Compaction And Yield Of Burley Tobacco, Edwin L. Ritchey, Robert C. Pearce, John H. Grove

Plant and Soil Sciences Research Report

Historically, tobacco producers have relied heavily on surface tillage to prepare fields for transplanting. This typically involved moldboard plowing, followed by several secondary tillage operations, such as discing then leveling with a soil finisher. Transplanter developments and modifications in the late 1990’s, coupled with new chemicals for weed control, made no-till (NT) tobacco a viable option for tobacco producers in Kentucky (KY).

Enantioselective Demethylation: The Key To The Nornicotine Enantiomeric Composition In Tobacco Leaf, Bin Cai

Theses and Dissertations--Plant and Soil Sciences

Nicotine and nornicotine are the two main alkaloids that accumulate in Nicotiana tabacum L. (tobacco), and nornicotine is the N-demethylation metabolite of nicotine. Nicotine is synthesized in the root, and probably primarily in the root tip. Both nicotine and nornicotine exist as two isomers that differ from each other by the orientation of H atom at the C-2' position on the pyrrolidine ring. (S)-nicotine is the dominant form in tobacco leaf and the enantiomer fraction of nicotine (EF_nic), the fraction of (R)-enantiomer over the total nicotine, is approximately 0.002. Despite considerable efforts to elucidate nicotine and nornicotine …