S112 A ten gene cluster responsible for synthesis of the anticanceralkaloid noscapine in opium poppy
Wednesday, July 23, 2014: 10:30 AM
Regency Ballroom B, Second Floor (St. Louis Hyatt Regency at the Arch)
Ian Graham, Centre for Novel Agricultural Products, University of York, York, United Kingdom
Opium poppy (Papaver somniferum) remains one of the most important medicinal

plants in the world due to the presence of a diverse set of benzylisoquinoline

alkaloids with potent pharmaceutical activities, the best known of which are the

morphinan subclass including codeine and morphine. Over the last five years we

have been funded by GlaxoSmithKline Australia to develop new poppy varieties

with improved levels of target alkaloids including noscapine, which has been used

as a human cough suppressant for decades and more recently has been shown to

have anticancer properties. While the biosynthesis of the morphinan alkaloids has

been characterised in detail over the last 20 years, very little was known about the

biosynthesis of noscapine. A major breakthrough came recently with our discovery

of a cluster of ten genes encoding five different enzyme classes responsible for

the production of noscapine (Winzer et al., 2012, Science, 336:1704-8). Functional

characterisation of a number of these genes by virus induced gene silencing

allowed a novel biosynthetic pathway to be proposed and molecular markers are

now allowing the gene cluster to be selected for as a single locus in a breeding

programme that is delivering new poppy varieties. An update on our work towards

the further characterisation of the pathway and evolution of the gene cluster will be

presented.