A method of modifying the content of certain chemical compounds in tobacco materials is provided, the method including treatment of a tobacco plant or portion thereof with at least one enzyme. For example, the method may modify the content of tobacco smoke toxicant precursors in tobacco materials, which can result in a modification in toxicant production when the tobacco material is exposed to elevated temperatures. The type of tobacco plant or portion thereof treated according to the invention can be, for example, a tobacco seed, a tobacco seedling, an immature live plant, a mature live plant, a harvested plant, or a plant derivative. Smoking articles and other tobacco products including such enzyme-treated tobacco materials are also provided.
