How the poppy evolved its pain-relieving properties

The unveiling of the poppy genome reveals how a collection of genes fused to endow the plant with its pain-relieving compounds.

Acording to researchers, the plant underwent a notable genome duplication event about 7.8 million years ago. Since the Neolithic times, humans have harvested the opium poppy (Papaver somniferum L.) for its various alkaloids including morphine and codeine, which yield effects ranging from pain relief and cough suppression to euphoria, sleepiness and addiction. 
Now, sequencing of the plant's genome reveals how the poppy came to produce these compounds. Li Guo and colleagues assembled about 95 per cent of the P. somniferum L. genome, finding that repetitive elements make up a substantial portion of the genetic code, and in particular, long terminal repeat retrotransposons —bits of DNA that duplicate in a way similar to viruses, are prominent. 
The researchers compared the poppy genome to the genomes of other plants including Aquilegia coerulea and Nelumbo nucifera, finding that the plants diverged from one another around 110 and 125 million years ago, respectively. 
A phylogenetic analysis demonstrated 65 per cent support of a whole genome duplication event occurring about 7.8 million years ago. 
The data reveal that, just before the whole genome was duplicated, a specific gene cluster became fused together in a manner that ultimately produces the morphine and codeine compounds that humans have enjoyed for so many years since.