The present invention relates to a method of reducing the content of at least one tobacco specific nitrosamine (TSNA) or a precursor of a TSNA in tobacco comprising expressing a deregulated cation efflux protein in a tobacco plant, or plant part thereof, or plant cell.

The present invention relates to a method of reducing the content of at least one tobacco specific nitrosamine (TSNA) precursor in tobacco, the method comprising modulating the activity or expression of at least one gene encoding a Walls are thin 1-related (WAT1-related) protein.