Isolated P.sub.450 polynucleotides and polypeptides are disclosed, including isolated cpd polynucleotide and CPD polypeptide sequences. The polypeptides can be orthologous CPD polypeptides to Arabidopsis CPD. Recombinant vectors, host cells, transgenic plants, and seeds that include the polynucleotides and/or polypeptides are also disclosed, as well as methods for preparing and using the same.