Abstract: The present invention relates to genetically modified plants of the species Papaver bracteatum wherein the type or amount of one or more alkaloids produced by the plants has been modified. Specifically, the genetically modified plants have an increased expression of one or more of thebaine 6-O-demethylase, codeine O-demethylase and/or codeinone reductase relative to wild type P. bracteatum such that the genetically modified poppy plants produce an increased quantity of an alkaloid selected from codeine, oripavine and/or morphine relative to a wild type P. bracteatum. Also provided are progeny plants having the genetically modified poppy plants described above as a parent; mutant or derivative plants of the aforementioned plants; reproductive material derived from, straw produced from, straw concentrate produced from, latex derived from, or one or more isolated cells derived from, the aforementioned plants.