The disclosure describes methods for the purification of protein-enriched extracts to provide concentrates and isolates and methods for incorporation of such materials into products. The purification methods are adapted for removal of one or more of ash, metal salts, alkaloids, particulates, heavy metals, and other impurities and/or contaminants from extracts, as well as modifying the sensory characteristics (e.g., odor, color, and/or taste characteristics) of extracts. The methods generally include diafiltration, treatment with functionalized resins, and supercritical extraction. A protein composition in the form of a concentrate or isolate is provided, the protein composition including RuBisCO, F2 fraction proteins, or combination thereof extracted from a plant of the Nicotiana species, wherein the protein composition is characterized by one or more of: an ash content of less than about 15% by weight; a nicotine content of less than about 10 ?g/g; and a heavy metal content of less than about 60 ?g/g.

The present invention provides a method for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, the method comprising modifying said tobacco plant or tobacco cell culture by inhibiting the activity or expression of a diterpene synthesis gene. The present invention also provides for the use of a diterpene synthesis gene for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, as well as tobacco cells, tobacco plants, tobacco plant propagation materials, harvested leaves, processed tobaccos, or tobacco products obtainable in accordance with the invention.

The present invention provides a method for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, the method comprising modifying said tobacco plant or tobacco cell culture by inhibiting the activity or expression of a diterpene synthesis gene. The present invention also provides for the use of a diterpene synthesis gene for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, as well as tobacco cells, tobacco plants, tobacco plant propagation materials, harvested leaves, processed tobaccos, or tobacco products obtainable in accordance with the invention.

The present disclosure provides approaches for reducing tobacco-specific nitrosamines (TSNAs) in tobacco. Some of these approaches include genetically engineering tobacco plants to increase one or more antioxidants, increase oxygen radicle absorbance capacity (ORAC), increase phenylalanine, or reduce nitrite. Also provided are methods and compositions for producing modified tobacco plants and tobacco products therefrom comprising reduced TSNAs.

The present invention features Nicotiana nucleic acid sequences such as sequences encoding constitutive, or ethylene or senescence induced polypeptides, in particular cytochrome p450 enzymes, in Nicotiana plants and methods for using these nucleic acid sequences and plants to alter desirable traits, for example by using breeding protocols.

The present invention features Nicotiana nucleic acid sequences such as sequences encoding constitutive, or ethylene or senescence induced polypeptides, in particular cytochrome p450 enzymes, in Nicotiana plants and methods for using these nucleic acid sequences and plants to alter desirable traits, for example by using breeding protocols.

The present invention features Nicotiana nucleic acid sequences such as sequences encoding constitutive, or ethylene or senescence induced polypeptides, in particular cytochrome p450 enzymes, in Nicotiana plants and methods for using these nucleic acid sequences and plants to alter desirable traits, for example by using breeding protocols.

The present invention features Nicotiana nucleic acid sequences such as sequences encoding constitutive, or ethylene or senescence induced polypeptides, in particular cytochrome p450 enzymes, in Nicotiana plants and methods for using these nucleic acid sequences and plants to alter desirable traits, for example by using breeding protocols.

The present invention relates to a mutant, non-naturally occurring or transgenic plant cell comprising: (i) at least one polynucleotide comprising, consisting or consisting essentially of a sequence encoding an isopropylmalate synthase and having at least 60% sequence identity to SEQ ID NO:1 or SEQ ID NO:10 or SEQ ID NO: 12 or SEQ ID NO:14; or (ii) a polypeptide encoded by said polynucleotide(s); or (iii) a polypeptide having at least 60% sequence identity to SEQ ID NO:2 or SEQ ID NO:11 or SEQ ID NO:13 or SEQ ID NO:15; or (iv) a construct, vector or expression vector comprising said polynucleotide sequence(s), optionally wherein said construct, vector or expression vector additionally comprises a promoter comprising, consisting or consisting essentially of the sequence set forth in SEQ ID NO:8 or a variant thereof with at least about 60% identity thereto or a trichome promoter.

The present invention relates to a mutant, non-naturally occurring or transgenic plant cell comprising: (i) at least one polynucleotide comprising, consisting or consisting essentially of a sequence encoding an isopropylmalate synthase and having at least 60% sequence identity to SEQ ID NO:1 or SEQ ID NO:10 or SEQ ID NO: 12 or SEQ ID NO:14; or (ii) a polypeptide encoded by said polynucleotide(s); or (iii) a polypeptide having at least 60% sequence identity to SEQ ID NO:2 or SEQ ID NO:11 or SEQ ID NO:13 or SEQ ID NO:15; or (iv) a construct, vector or expression vector comprising said polynucleotide sequence(s), optionally wherein said construct, vector or expression vector additionally comprises a promoter comprising, consisting or consisting essentially of the sequence set forth in SEQ ID NO:8 or a variant thereof with at least about 60% identity thereto or a trichome promoter.