Biosynthesis of opiate alkaloids

A method to produce a P. somniferum plant that has altered expression of a polypeptide, comprising:

• i) mutagenizing a wild-type seed from a wild-type P. somniferum plant that expresses said polypeptide, thereby generating mutagenized seed;
• ii) cultivating the mutagenized seed to produce first and subsequent generations of mutagenized plants;
• iii) obtaining seed from the first and subsequent generations of mutagenized plants;
• iv) determining if the plants from the seed from said first and subsequent generations of mutagenized plants have an altered nucleotide sequence, altered expression of said polypeptide or both, an altered nucleotide sequence and altered expression of said polypeptide by obtaining a nucleic acid sample from the plant of said first or subsequent generation of mutagenized plants and analysing the nucleic acid sample for presence of a nucleic acid molecule comprising a nucleotide sequence having at least 90% sequence identity to the sequence of SEQ ID NO:
• 7, 8, 9 or 10 and that encodes a polypeptide with opiate alkaloid biosynthetic activity;
• and optionally
• v) comparing the nucleotide sequence of the nucleic acid molecule in said sample to a nucleotide sequence of a nucleic acid molecule of the wild-type plant.