Dr Michael Stephenson

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I am a chemist, with a background in natural product total synthesis, medicinal chemistry, and pharmacy. In the Osbourn group we are interested in plant secondary metabolites, and this places us at the very interface between biology and chemistry. I bring expertise in small organic molecule extraction, purification, and structural characterisation. This strengthens the group’s ability to functionally characterise biosynthetic enzymes; something which is important for many areas of research within the Osbourn lab. As such, I am involved in a number of different projects.

My main focus is on the application of transient expression in Nicotiana benthamiana towards the preparative production of high value triterpenes. I have been heavily involved in platform and method development, improving both the efficiency and scalability of procedures used within the group. I have also demonstrated the preparative utility of this platform by producing triterpenes on the gram scale.

As a medicinal chemist I am interested in applying these techniques to engineer chemical diversity, and to explore the structure activity relationships of bioactive triterpenes. I have been involved in isolating and characterising several novel triterpenes structures arising from co-expression of ‘un-natural’ combinations of biosynthetic enzymes. In addition, I have solved the structure of a number of novel and usual triterpene scaffolds, produced by oxidosqualene cyclases under investigation within the group. It would seem that despite the huge number of unique triterpene scaffolds already reported from many decades of natural product isolation, there is still a wealth of novel chemistry to be discovered, and that its discovery can be accelerated by utilising synergy between bioinformatives, synthetic biology, and chemistry.

In addition to my research, I also take a keen interest in public engagement. I have been involved in several outreach events where we attempt to present concepts in synthetic biology and chemistry in an assessable and ‘hands on’ way.    

Dr Ivan Reyna-Llorens

My research involves using synthetic biology and evolution for improving agricultural traits, more specifically to improve photosynthesis. As the world population continues to expand, it is predicted that crop yields will have to increase by 50% over the next 35 years. Traditional breeding programs cannot keep pace with this current population growth rate. Plant biomass is produced by carbon dioxide (CO2) fixed by the enzyme Rubisco during photosynthesis.

This process known as C3 photosynthesis can be very inefficient as Rubisco also interacts with Oxygen (O2) in a wasteful process known as photorespiration. In order to increase yields, photorespiration should be reduced considerably. Fortunately, some plants have evolved such mechanism already. C4 photosynthesis results from a series of anatomical and biochemical modifications in the leaf that lead to photosynthesis being compartmentalized between mesophyll and bundle sheath cells. This division of labour generates a CO2 enriched environment where photorespiration is effectively abolished. C4 plants therefore produce more yield and use water and nitrogen more efficiently. The fact that C4 photosynthesis has evolved independently in more than 60 lineages allows us to think it is possible to engineer C4 photosynthesis in C3 plants. In order to engineer this trait, cell specific genetic circuits need to be developed. Unfortunately there is a limited number of genetic parts driving cell specificity in leaves. My main objective in OpenPlant is to generate a library of leaf specific motifs that can be used to drive the expression of both nuclear and plastid encoded genes in specific compartments and specific cells of leaves.

Together with colleagues in the Department of Plant Sciences, Department of Chemistry and the Depart­ment of Physics I am part of an OpenPlant fund project that aims to use microfluidics for high-throughput analysis of genetic parts. We hope to generate a whole toolbox of parts that are useful to rewire different traits.

Dr Oleg Raitskin

My project involves optimization of CRISPR/Cas9 methodology of genome editing in plants. CRISPR/Cas9 is a method of choice to perform genome engineering. There are however significant limitations which prevent broader implementation of this technology in plants.

These limitations include variable efficiency of editing at different targets, off target activity, inefficient inheritance of the created mutations, ability to edit simultaneously several targets, limited selection of targets/PAM repertoire and the need to segregate Cas9 and sgRNA from the created mutations. Numerous configurations of CRISPR/Cas9 designed to address these limitations had been published. Our aim is to establish a uniform testbed and toolkit, where many of these configurations are tested under the same conditions and their editing efficiency and off target activity will be assessed. In order to minimize variability in transgenic expression we established editing essay in plant protoplasts.

Our experimental design includes transforming protoplasts from the same harvest with different configurations of CRISPR/Cas9, including Cas9 variants which specifically edit NGG, NGAG, NGCG and NNGGGT PAMs , Cpf1s which recognise TTTN PAM, and SpCas9 variants with reduced off target activity, and assessing frequency of indels and double stranded breaks activity employing DNA capture assays and Next Generation Sequencing. Currently we gained experience in efficient extraction and transformation of the protoplasts from different plant species using our CRISPR/Cas9 constructs and we are establishing high throughput protoplast transformation methodology using automatic dispenser. In the next step we will attempt to regenerate plants from the edited protoplasts. We also trying to find the ways to perform successful CRISPR/Cas9 assisted targeted repair of gene of interest. We follow the two-step strategy: transforming the plants with “landing pad” with subsequent insertion of the repair template. Successful insertion of the repair template should restore the herbicide resistance and facilitate selection of the plants with successful repair.

I participate in the proposal for Open Plant funding titled “Establishing Low Cost Microfluidic System for Single Cell Analysis” (Dr. Steven Burgess is a principal applicant). The aim of the project is to establish cost-effective microfluidic device for single cell sorting and analysis. Significant reduction of the cost comparatively to the commercially available systems is achieved by producing some of the parts of the device such as microscope and syringe part with 3D printing technology and utilizing open source materials and repositories. Among various applications for this device will be sorting the transformed protoplasts according to the cell size and strength of the fluorescence of the transgene, and cost-effective miniaturizing and automatizing Golden Gate cloning assembly reactions.

Dr Hans-Wilhelm Nützmann

Plants produce a wide variety of specialised metabolites. These molecules play key roles in the interaction of plants with their biotic and abiotic environment. In addition to their ecological functions, plant-derived specialised metabolites are major sources of pharmaceuticals and other high-value compounds.

Recently, it was discovered that the genes for the biosynthesis of several major classes of these compounds are physically co-localised in so called ‘gene clusters’ in plant genomes. Such clustering of non-homologous genes contrasts the expected arrangement of genes in eukaryotic genomes. The co-localisation of functionally-related genes enables the formation of fundamentally different mechanisms of gene regulation in comparison to the control of dispersed genes. The purpose of this project is to improve our understanding of the transcriptional control of plant metabolic gene clusters. The focus within OpenPlant will be on chromatin related regulatory processes that govern the expression of gene clusters. By chromatin immunoprecipitation, chromosome conformation analyses and genome engineering we aim to characterise the chromatin environment at gene clusters and its impact on cluster regulation. The findings of this project will open up new opportunities for the discovery and engineering of metabolic pathways using genetic and chemical approaches. They will also underpin synthetic biology-based approaches aimed at refactoring of plant metabolic gene clusters and the development of synthetic traits.

Dr Thomas Meany

I am jointly hosted by the labs of Lisa Hall (Chemical Engineering and Biotechnology) and Jim Haseloff (Plant Science) as an interdisciplinary fellow part funded through OpenPlant. My background training is as a physicist, with a specific emphasis on optics and microfabrication. I undertook a PhD in Macquarie University (Sydney, Australia) where I developed microphotonic circuits using a 3D laser printing technique. My postdoctoral research continued in Toshiba’s Cambridge Research Labs where I worked on advanced manufacturing techniques for semiconductor quantum dots.

As a part of OpenPlant I am passionate about using optical analytical tools to study the production of secondary metabolites in specialised plant tissues. Specifically, the oil bodies of the Liverwort, Marchantia polymorpha, are potentially rich reservoirs of bio-active compounds. Using Raman microscopy, a label-free, non-destructive spectroscopy technique it is possible to study metabolic processes in real-time. As this is non-destructive it can be performed in situ and therefore both spatial and temporal information can be obtained. My hope is to correlate this data with information available using other approaches such as Matrix Assisted Laser Deposition Ionisation Mass Spectroscopy (MALDI), Gas Chromatography Mass Spectrometry (GC-MS), fluorescence microscopy and other high resolution analytical approaches. In future this could be then adapted to studies of transgenic plant species as an additional tool to study metabolic pathways. Additional model species can also be explored, for instance Nicotiana benthamiana, and potentially crop plants. I am keen to engage with teams operating in the area of natural product chemistry, metabolic engineering or teams focused on alternative analytical approaches.

Photo: Prototype microfluidic rapid 3D printed circuit fabricated during the Bio-Hackathon.

Working with the Cambridge University Technology and Enterprise club (CUTEC), I organised the UK’s first Bio-Hackathon, hosted in the Department of Plant Science (Cambridge) during the week of 21-25 June 2016. This was possible with thanks, in part, to a grant provided by the University of Cambridge Synthetic Biology Strategic Research Initiative. This event brought together a diverse interdisciplinary group of 50 participants from across the UK and the world. Teams focused on “bioware” by incorporating hardware, software and wet lab tools. One team developed a 3D printed microfluidic prototyping tool, another built a comparison software tool for DNA synthesis pricing. The winning team built a tool called “Alpha-Brick” which is a drag and drop tool for assembling bio-bricks and plugs directly into Transcriptic (a cloud laboratory) allowing immediate order of an assembled part.