Loading patent…
AssigneesNorth Carolina State University, University of Kentucky Research Foundation
InventorsRalph E. Dewey, Steven W. Bowen, Balazs Siminszky, Lily Gavilano
Estimating the term…
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 the production of tobacco products that have reduced levels of nornicotine and its carcinogenic metabolite, NNN, and thus reduced carcinogenic potential for individuals consuming these tobacco products or exposed to secondary smoke derived from these products.
A method for reducing the level of nornicotine or N′-nitrosonornicotine in a plant of the genus Nicotiana or a plant part thereof, said method comprising growing a plant of the genus Nicotiana, wherein said plant, or a plant part thereof, comprises an introduced expression cassette that comprises an inhibitory sequence that is operably linked to a promoter that is functional in a plant cell, wherein said inhibitory sequence comprises a first nucleotide sequence, wherein said first nucleotide sequence is a fragment of a polynucleotide having at least 90% sequence identity to the sequence set forth in SEQ ID NO:3, wherein said fragment is from a region of said polynucleotide selected from the group consisting of:
A method for reducing the level of nornicotine or N′-nitrosonornicotine in a tobacco product, said method comprising preparing said tobacco product from a tobacco plant, or a plant part thereof, that has been genetically modified to inhibit the expression of a cytochrome P450 that is involved in the metabolic conversion of nicotine to nornicotine in said tobacco plant, or said plant part thereof, wherein expression of said cytochrome P450 in said tobacco plant, or said plant part thereof, is inhibited by introduction of an expression cassette into said tobacco plant, or a plant part thereof, wherein said expression cassette comprises an inhibitory sequence that is operably linked to a promoter that is functional in a plant cell, wherein said inhibitory sequence comprises a first nucleotide sequence, wherein said first nucleotide sequence is a fragment of a polynucleotide having at least 90% sequence identity to the sequence set forth in SEQ ID NO:3, wherein said fragment is from a region of said polynucleotide selected from the group consisting of:
Dependencies are inferred from the claim text.