Professor Lee Sweetlove
Professor of Plant Sciences
Rational engineering of plant metabolic networks
The growth of plants is underpinned by, and in many cases limited by, the capacity of their metabolic systems. In green tissues, the process of photosynthesis transduces light energy into chemical energy to power the assimilation of carbon and nitrogen from the environment, the biosynthesis and maintenance of cellular components and export of sugars and amino acids to support the growth of the rest of plant. There is renewed interest in these metabolic processes due to concerns about the productivity of the global agricultural system in relation to an ever-increasing demand for food.
The research in my lab aims to develop a better understanding of the behaviour of the metabolic systems of plants in order to devise metabolic engineering strategies that will improve the productivity and quality of crop plants. We use both computational and experimental approaches to achieve this.
Computational: we construct and analyse flux-balance models of large-scale (up to genome-scale) plant metabolic networks. We have spent the last few years refining the approach such that we are confident that these minimally-constrained models provide a realistic simulation of plant metabolism in leaves and non-photosynthetic tissues. The goal now is to exploit these models to design more efficient metabolic systems. We are particularly interested in using this approach to predict how the leaf metabolic network needs to be modified to accommodate more efficient photosynthetic modes such as C4 photosynthesis and CAM. We are also starting the process of integrating these metabolic models into whole-plant modelling frameworks.
Experimental: The experimental strand aims to implement the predicted metabolic engineering strategies from the computational strand. We are using biolistic co-transformation to systematically explore combinatorial transgenic interventions in leaf metabolism. We are currently using tobacco as a model species, but are also looking to develop the liverwort, Marchantia polymorpha, as a rapid testbed for synthetic biology approaches to improving the efficiency of the core metabolic network of plants. Finally, we are also collaborating with Mark Howarth, Department of Biochemistry, University of Oxford, to explore the potential of ‘molecular superglues’ as a mechanism for greater control over introduced metabolic pathways.