A mutant, non-naturally occurring tobacco plant or tobacco plant cell comprising (a) a polynucleotide selected from the group consisting of: (i) a polynucleotide comprising, consisting or consisting essentially of a sequence having at least 71 % sequence identity to SEQ ID NOs: 1, 2, 27, 28 or 29 or 51； or (ii)a polynucleotide comprising, consisting or consisting essentially of a sequence having at least 65 % sequence identity to any of SEQ ID NOs: 3 to 23 or 30 to 50； or (iii) a polynucleotide encoding a NtMRP polypeptide comprising, consisting or consisting essentially of a sequence having at least 65% sequence identity to any of SEQ ID NOs. 24 to 26 or 52, and wherein the polypeptide has heavy metal transporter activity； wherein expression of NtMRP polynucleotide and the activity of the protein encoded thereby or the activity of the protein encoded thereby is decreased and the leaves of said plant have a reduction in cadmium content of at least 5% as compared to a control plant in which the expression of NtMRP and the activity of the protein encoded thereby or the activity of the protein encoded thereby has not decreased.
