Compositions and methods for minimizing nornicotine synthesis in tobacco
First Claim
1. A tobacco seed, a tobacco plant grown therefrom, or a tobacco product comprising tobacco plant material from said tobacco plant, wherein said tobacco seed, tobacco plant, or tobacco product comprises a mutated CYP82E10 polypeptide encoded by a first locus having at least 95% sequence identity to the full length of SEQ ID NO:
- 4, wherein said mutated CYP82E10 polypeptide has inhibited nicotine demethylase activity as compared to the CYP82E10 polypeptide encoded by SEQ ID NO;
4, and wherein said tobacco is Nicotiana tabacum.
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Accused Products
Abstract
Compositions and methods for reducing the level of nornicotine and N′-nitrosonornicotine (NNN) in tobacco plants and plant parts thereof are provided. The compositions comprise isolated polynucleotides and polypeptides for a root-specific nicotine demethylases, CYP82E10, and variants thereof, that are involved in the metabolic conversion of nicotine to nornicotine in these plants. Compositions of the invention also include tobacco plants, or plant parts thereof, comprising a mutation in a gene encoding a CYP82E10 nicotine demethylase, wherein the mutation results in reduced expression or function of the CYP82E10 nicotine demethylase. Seed of these tobacco plants, or progeny thereof, and tobacco products prepared from the tobacco plants of the invention, or from plant parts or progeny thereof, are also provided. Methods for reducing the level of nornicotine, or reducing the rate of conversion of nicotine to nornicotine, in a tobacco plant, or plant part thereof are also provided. The methods comprise introducing into the genome of a tobacco plant a mutation within at least one allele of each of at least three nicotine demethylase genes, wherein the mutation reduces expression of the nicotine demethylase gene, and wherein a first of these nicotine demethylase genes encodes a root-specific nicotine demethylase involved in the metabolic conversion of nicotine to nornicotine in a tobacco plant or a plant part thereof. 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.
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Citations
18 Claims
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1. A tobacco seed, a tobacco plant grown therefrom, or a tobacco product comprising tobacco plant material from said tobacco plant, wherein said tobacco seed, tobacco plant, or tobacco product comprises a mutated CYP82E10 polypeptide encoded by a first locus having at least 95% sequence identity to the full length of SEQ ID NO:
- 4, wherein said mutated CYP82E10 polypeptide has inhibited nicotine demethylase activity as compared to the CYP82E10 polypeptide encoded by SEQ ID NO;
4, and wherein said tobacco is Nicotiana tabacum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
- 4, wherein said mutated CYP82E10 polypeptide has inhibited nicotine demethylase activity as compared to the CYP82E10 polypeptide encoded by SEQ ID NO;
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17. A tobacco seed, a tobacco plant grown therefrom, or a tobacco product comprising tobacco plant material from said tobacco plant, wherein said tobacco seed, tobacco plant, or tobacco product comprises a mutation positioned between nucleotide 1872 and nucleotide 2483 as compared to SEQ ID NO:
- 4 at a locus having at least 95% sequence identity to the full length of SEQ ID NO;
4, wherein said tobacco is Nicotiana tabacum.
- 4 at a locus having at least 95% sequence identity to the full length of SEQ ID NO;
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18. A tobacco seed, a tobacco plant grown therefrom, or a tobacco product comprising tobacco plant material from said tobacco plant, wherein said tobacco seed, tobacco plant, or tobacco product comprises a mutation positioned between nucleotide 115 and nucleotide 1053 as compared to SEQ ID NO:
- 4 at a locus having at least 95% sequence identity to the full length of SEQ ID NO;
4, wherein said tobacco is Nicotiana tabacum.
- 4 at a locus having at least 95% sequence identity to the full length of SEQ ID NO;
Specification