The present invention provides a tobacco plant plant part and/or plant cell comprising one or more heterologous nucleic acid molecules comprising a nucleotide sequence encoding a pseudooxynicotine degrading enzyme. Further provided are methods and compositions for producing tobacco plants and tobacco products having reduced pseudooxynicotine (PON) and/or 4 (methyl nitrosoamino) 1 (3 pyridyl) 1 butanone (NNK) content.