ECR Seminar - Plants and Synthetic Biology
Zoom webinar link: https://bristol-ac-uk.zoom.us/j/95638095638
Plants and Synthetic Biology
Reprogramming plant root growth using synthetic developmental regulation.
Dr Jenn Brophy, Stanford University
The shape of a plant’s root system influences its ability to reach essential nutrients in the soil or to acquire water during drought. Progress in engineering plant roots to optimize water and nutrient acquisition has been limited by our capacity to design and build genetic programs that alter root growth in a predictable manner. Key to reprogramming growth is precise control over spatial patterns of gene expression. We are building synthetic gene circuits to express developmental transcription factors with high spatial precision across root tissues. These circuits use logical operations to combine the activity of tissue specific promoters and generate new spatial patterns of gene expression. We show that specific changes to root branching can be achieved by expressing mutant auxin-response transcription factors (AUX/IAAs) in specific root cells. This work highlights the potential of genetic circuits to enable precise spatial, temporal, and magnitudinal control over gene expression across entire organ systems and offers an exciting means to reprogram plant growth.
Genome engineering of Nicotiana benthamiana as an improved plant-based bioproduction system for medicinal alkaloids.
Dr Quentin Dudley, Earlham Institute - John Innes Centre
The wild tobacco relative Nicotiana benthamiana is an ideal chassis for solar-powered production of plant metabolites since it allows high level transient expression of heterologous multi-enzyme pathways in just a few days. However, small molecule compounds and their intermediate pathway metabolites are often over-glycosylated, oxidized/reduced, acylated or modified with glutathione. Therefore, to improve N. benthamiana as a plant-based bioproduction platform, we are using the CRISPR-Cas9 genome engineering to deactivate native enzymes that make unwanted modifications to the 11-step pathway to strictosidine (the monoterpene indole alkaloid precursor to the anti-cancer drug vinblastine). We have used transcriptomic and phylogenetic analysis of an improved genome assembly to select candidate genes for inactivation from among thousands of possible enzymes and have generated several knockout lines. In parallel, we found that co-expression of a newly discovered cyclase from catmint relieves a key metabolic pathway bottleneck step. We anticipate that edited N. benthamiana lines will reduce unwanted metabolite derivatization and enable increased production of target metabolites.
Marchantia polymorpha: an emerging system for plant synthetic biology.
Dr Eftychis Frangedakis, University of Cambridge and Open Plant
The bryophyte Marchantia polymorpha is a powerful experimental model for plant biology studies. Marchantia is also emerging as a promising system for plant synthetic biology application thanks to its unique combination of characteristics. It has a small size and simple morphology, grows rapidly under laboratory conditions and has a remarkable regenerative capacity. The dominant phase of its life cycle is haploid, it has a small genome and can reproduce asexually by means of clonal propagules called gemmae, which provide an excellent platform for live-tissue microscopy. Marchantia is also one of the few land plant species for which both nuclear and chloroplast transformation is well established. We have developed a series of standardised tools for whole-plant Marchantia engineering. The wide availability of all these resources will greatly facilitate the exploitation of both nuclear and chloroplast Marchantia engineering.