Plants are incredible chemical factories, capable of producing a host of complex molecules that synthetic chemists struggle to produce. These compounds are produced by plants to interact with their environment, but they also have great significance for humans, as we use them for fragrances, agrichemicals and medicines. My general research interests are understanding how plants produce these valuable compounds, and how these pathways have evolved. This knowledge can then be used to produce natural products and novel chemicals in microbial or plant based platforms.
I am currently working with catnip and catmint (Nepeta cataria and N. mussinii), plants famous for their intoxicating effect on cats. The origin of this activity is the nepetalactones, a group of volatile compounds from the iridoid family of natural products. Along with their role as feline attractants, nepetalactones have also been reported to have both insect pheromone and insect repellent properties, in some cases having activities superior to DEET. The biosynthetic origin of these compounds is currently unknown. We have been using transcriptomics and proteomics to discover enzymes in the Nepeta nepetalactone biosynthesis pathway.
This work is being performed in the context of a wider chemical and genetic investigation into the mint family (Lamiaceae), a large plant family of economic importance in which Nepeta resides. I am working closely with the Mint Genome Project (funded by the NSF) to understand the evolution and regulation of natural product biosynthesis across the entire plant family. By placing newly discovered Nepeta enzymes in a detailed phylogenetic context we hope to understand the evolutionary origin of nepetalactone biosynthesis in Nepeta, and ultimately use it as a case-study for natural product evolution.
I am currently undertaking training in molecular evolution and phylogenetics with the aim of taking the principles of evolution into synthetic biology. I hope that this will reveal new methods of optimising and editing synthetic biology systems and devices.
Figure 1. Nepetalactone biosynthesis pathway in Nepeta. We are attempting to discover the enzymes that catalyse the formation of all different nepetalactone isomers. We are also attempting to understand how these enzymes have evolved. In the background is Nepeta mussinii.