Patent ID: 7884263

Claim:
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) a region that corresponds to nucleotide position 265 to nucleotide position 625 of SEQ ID NO:3, or a complement thereof; and b) a region that corresponds to nucleotide position 1420 to nucleotide position 1580 of SEQ ID NO:3, or a complement thereof; the size of said fragment being from about 100 nucleotides to the full length of said region.