Genetic locus imparting a low anatabine trait in tobacco and methods of using

1. A tobacco product comprising cured leaf from a tobacco plant having a mutation in an endogenous gene encoding a cDNA sequence having at least 90% identity to SEQ ID NO: 7, wherein the mutation provides an amino acid substitution at a position corresponding to the cysteine residue at position 487 or the valine residue at position 516 of SEQ ID No: 8.

2. The tobacco product of claim 1 , wherein the cured leaf exhibits a reduced amount of at least one tobacco-specific nitrosamine (TSNA) relative to cured leaf from a plant lacking the mutation.

3. The tobacco product of claim 2 , wherein the at least one TSNA is N + -nitrosoanatabine.

4. The tobacco product of claim 1 , wherein the tobacco product is selected from the group consisting of smokeless tobacco products, tobacco-derived nicotine products, cigarillos, non-ventilated recess filter cigarettes, vented recess filter cigarettes, cigars, snuff, pipe tobacco, cigar tobacco, cigarette tobacco, chewing tobacco, leaf tobacco, shredded tobacco, and cut tobacco.

5. The tobacco product of claim 1 , wherein said mutation comprises a tyrosine at amino acid position 487 of SEQ ID NO: 8.

6. The tobacco product of claim 1 , wherein said mutation comprises an isoleucine at amino acid position 516 of SEQ ID NO: 8.

7. A tobacco product comprising cured leaf from a tobacco plant having a mutation in a gene encoding a polypeptide sequence having at least 90% identity to SEQ ID NO: 8, wherein the mutation results in an amino acid substitution at a position corresponding to the cysteine residue at position 487 or the valine residue at position 516 of SEQ ID No: 8.

8. The tobacco product of claim 7 , wherein the polypeptide sequence has at least 95% identity to SEQ ID NO: 8.

9. The tobacco product of claim 7 , wherein the polypeptide sequence has 100% identity to SEQ ID NO: 8.

10. The tobacco product of claim 7 , wherein the mutation results in a cysteine to tyrosine substitution at a position corresponding to the cysteine residue at position 487 of SEQ ID No: 8.

11. The tobacco product of claim 7 , wherein the mutation results in a valine to isoleucine substitution at a position corresponding to the valine residue at position 516 of SEQ ID No: 8.

12. The tobacco product of claim 7 , wherein the cured leaf comprises a reduced amount of anatabine relative to a cured control leaf from a control plant lacking the mutation.

13. The tobacco product of claim 12 , wherein the reduced amount of anatabine is reduced by about 50% to about 85%.

14. The tobacco product of claim 12 , wherein the reduced amount of anatabine is reduced by about 50% to about 95%.

15. The tobacco product of claim 7 , wherein the cured leaf exhibits an anatabine percentage of less than 0.5%.

16. The tobacco product of claim 7 , wherein the mutation does not reduce nicotine in the cured leaf.

17. The tobacco product of claim 7 , wherein the cured leaf exhibits a reduced amount of at least one tobacco-specific nitrosamine (TSNA) relative to cured leaf from a plant lacking the mutation.

18. The tobacco product of claim 17 , wherein the at least one TSNA is N′-nitrosoanatabine.

19. The tobacco product of claim 7 , wherein the tobacco product is selected from the group consisting of smokeless tobacco products, tobacco-derived nicotine products, cigarillos, non-ventilated recess filter cigarettes, vented recess filter cigarettes, cigars, snuff, pipe tobacco, cigar tobacco, cigarette tobacco, chewing tobacco, leaf tobacco, shredded tobacco, and cut tobacco.

20. The tobacco product of claim 1 , wherein the cDNA sequence has at least 95% identity to SEQ ID NO: 7.

21. The tobacco product of claim 1 , wherein the cDNA sequence has 100% identity to SEQ ID NO: 7.

22. The tobacco product of claim 1 , wherein the mutation results in a cysteine to tyrosine substitution at a position corresponding to the cysteine residue at position 487 of SEQ ID No: 8.

23. The tobacco product of claim 1 , wherein the mutation results in a valine to isoleucine substitution at a position corresponding to the valine residue at position 516 of SEQ ID No: 8.

24. The tobacco product of claim 1 , wherein the cured leaf comprises a reduced amount of anatabine relative to a control plant lacking the mutation.

25. The tobacco product of claim 24 , wherein the reduced amount of anatabine is reduced by about 50% to about 85%.

26. The tobacco product of claim 24 , wherein the reduced amount of anatabine is reduced by about 50% to about 95%.

27. The tobacco product of claim 1 , wherein the cured leaf exhibits an anatabine percentage of less than 0.5%.

28. The tobacco product of claim 1 , wherein the mutation does not reduce nicotine in the cured leaf.

29. A tobacco product comprising cured leaf from a tobacco plant having a mutation in an endogenous quinolinate synthase gene, wherein the mutation reduces anatabine in the cured leaf without reducing nicotine relative to a cured leaf from a control tobacco plant lacking the mutation.

30. The tobacco product of claim 29 , wherein the mutation is in a residue fully conserved in wild-type quinolinate synthase proteins shown in FIG. 5 .

31. The tobacco product of claim 29 , wherein the mutation results in an amino acid substitution at a position corresponding to the cysteine residue at position 487 or the valine residue at position 516 of SEQ ID No: 8.

32. The tobacco product of claim 29 , wherein the mutation results in a cysteine to tyrosine substitution at a position corresponding to the cysteine residue at position 487 of SEQ ID No: 8.

33. The tobacco product of claim 29 , wherein the mutation results in a valine to isoleucine substitution at a position corresponding to the valine residue at position 516 of SEQ ID No: 8.