The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of polynucleotides, primary transcripts and mmRNA molecules.

Plant T-DNA expression vectors encoding a post-translational modification (PTM) enzyme wherein the nucleic acid encoding the PTM enzyme has neither a promoter nor a 5 untranslated region (UTR) are provided. Also provided are methods of optimizing expression and glycosylation of recombinant protein produced in plants by utilizing the plant T-DNA expression vectors.

Plant T-DNA expression vectors encoding a post-translational modification (PTM) enzyme wherein the nucleic acid encoding the PTM enzyme has neither a promoter nor a 5 untranslated region (UTR) are provided. Also provided are methods of optimizing expression and glycosylation of recombinant protein produced in plants by utilizing the plant T-DNA expression vectors.

The present invention provides a method for modulating the alkaloid content of a plant (e.g. a tobacco plant), the method comprising modifying said plant by modulating the activity or expression of Galactose-1-phosphate uridyl transferase. The present invention also provides for the use of Galactose-1-phosphate uridyl transferase for modulating the alkaloid content of a plant, as well as tobacco cells, plants, plant propagation materials, harvested leaves, processed tobaccos, or tobacco products obtainable in accordance with the invention.