Project Title:

Strategies to increase production of betalain pigments and their use as SynBio tools.

Project Summary:

Betalains are plant pigments showing a wide range of potential applications in the pharmacological, biotechnological and commodity sectors. They are currently being used as natural food colorants and intermediates of the biosynthetic pathway exhibit important pharmacological properties (e.g. L-DOPA). There is an increasing interest in improving existing plant sources and obtaining new bio-industrial methods for semi-synthetic production. Betalain biosynthesis is achieved in plants via a relatively short metabolic pathway which has been successfully engineered in a diversity of heterologous hosts including plants, bacteria and yeast. We are exploring a variety of mechanisms to enhance betalain production and maximize pigment yield via molecular engineering as well as realizing their potential as tools for synthetic biology. We have identified and isolated a series of enzyme variants which display elevated activity for pigment production and proved their potential in bacterial bioreactors for industrial pigment production. Betalains can also be used as in vivo markers for the dynamic visualization of tissue-specific physiological and developmental processes. Here we, explore the engineering of the betalain pathway under the control of physiological specific promoters for the localised production of red and fluorescent yellow natural plant pigments. Easily observable by the naked eye, this offers a useful alternative over more invasive staining methods that generally require the sacrifice of the plant or tissue, thus paving the way for a dynamic visible in-vivo reporter system based on natural plant pigments.