A Transcriptomic Approach to Understanding Polymorphic and Transcript Level Differences Linked to Isoquinoline Alkaloid Biosynthesis in Triploid Varieties of Narcissus pseudonarcissus

The Amaryllidaceae alkaloids are isoquinoline alkaloids found only in plants of the Amaryllidaceae family. One such member of this family, the daffodil (Narcissus pseudonarcissus), is used as a source of galanthamine, an alkaloid currently approved for use in the treatment of Alzheimer’s disease. This project looks at two triploid varieties of daffodil, Carlton, an industry standard variety with well known high levels of galanthamine, and Andrew’s Choice, a lesser used variety with low levels of the alkaloid.

A reference transcriptome was created for Carlton using next generation sequencing . This, along with Illumina reads from both Carlton and Andrew’s Choice, has been used to create a pipeline to identify polymorphisms and transcript level differences between the two varieties. The strategy so far has applied a mixture of bespoke scripts and freely available SNP finding programs for polymorphisms in polyploids to create a pipeline that can be used for universal polymorphism discovery in polyploids.

In order to focus this work on the production of the amaryllidaceae alkaloids, the resulting contigs with SNPs and transcript level differences have been mined for similarities to genes from other more widely studied alkaloid-producing plants. By looking at the known pathways of alkaloid production in Papaver somniferum and Capsicum annuum it is hoped that biomarkers linked to galanthamine production can be determined.