Compositions and methods for minimizing nornicotine synthesis in tobacco
First Claim
1. Cured tobacco material or a tobacco product comprising said cured tobacco material, wherein said cured tobacco material is made from a tobacco plant comprising a mutant CYP82E10 gene encoding a truncated CYP82E10 polypeptide comprising a mutation compared to SEQ ID NO:
- 2, wherein said mutant CYP82E10 gene results in reduced expression or function of said CYP82E10 polypeptide when compared to the activity of a wild-type CYP82E10 polypeptide under the same test conditions.
1 Assignment
0 Petitions
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.
90 Citations
20 Claims
-
1. Cured tobacco material or a tobacco product comprising said cured tobacco material, wherein said cured tobacco material is made from a tobacco plant comprising a mutant CYP82E10 gene encoding a truncated CYP82E10 polypeptide comprising a mutation compared to SEQ ID NO:
- 2, wherein said mutant CYP82E10 gene results in reduced expression or function of said CYP82E10 polypeptide when compared to the activity of a wild-type CYP82E10 polypeptide under the same test conditions.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
9. Cured tobacco material or a tobacco product comprising said cured tobacco material, wherein said cured tobacco material comprises a polynucleotide comprising a mutation in a CYP82E10 exon 1 sequence as compared to SEQ ID NO:
- 4, wherein said mutation results in reduced expression or function of a CYP82E10 polypeptide encoded by said polynucleotide when compared to the activity of a wild-type CYP82E10 polypeptide under the same test conditions.
- View Dependent Claims (10, 11, 12, 13, 14, 15)
- 16. Cured tobacco material or a tobacco product comprising said cured tobacco material, wherein said cured tobacco material comprises a null mutation in a polynucleotide encoding a CYP82E10 polypeptide comprising a mutation compared to SEQ ID NO:
Specification