Evolutionary guided engineering to improve C4 photosynthesis - AfS, ENWW

There are three different types of photosynthesis (C3, C4, and CAM) that plants use to capture energy form sunlight and store it in carbohydrates. Both C4 and CAM photosynthesis are evolutionary adaptations of C3 photosynthesis. C4 plants are on average more efficient than their C3 ancestors at converting solar energy into biomass. Interestingly, the C4 pathway evolved at least 62 times independently from a C3 ancestor plant. Thus, it is one of the most frequently occurring examples of convergent evolution in eukaryotic biology. Although we have a detailed understanding of the biochemistry of C4 photosynthesis, we know little about the molecular evolution that has enabled and optimised the C4 pathway. This first aim of this project is to address this knowledge gap and identify the key molecular sequence changes that modulate the efficiency of C4 photosynthesis. This aim will be achieved by analysing a large transcriptomic dataset that contains 18 independent origins of C4 photosynthesis to identify genes and sites within genes that show evidence of selection. Given that C4 photosynthesis has evolved at least 62 times in a relatively short period of time, it is likely that in certain C4 lineages individual gene products will have better characteristics or efficiencies than the orthologous counterpart other lineages. Thus the second aim of this project is to utilise this dataset to improve the efficiency of C4 photosynthesis in the model plant Setaria viridis. This aim will be achieved by characterising variants of gene products that were identified in the first part of the project through in vitro and in planta experimentation. Thus in summary this project will identify the protein sequence changes that occur when plants evolve C4 photosynthesis, identify those changes that best adapt the protein for function in C4 photosynthesis, and determine the impact that engineering the best performing variants has on photosynthesis and yield in the C4 model plant Setaria viridis. If successful, this evolutionarily guided approach could provide a paradigm for improving photosynthesis in the world's most important C4 crops.

BBSRC priority areas
1) Food, nutrition and health 2) Bioenergy: generating new replacement fuels for a greener and sustainable future. 3) Data driven biology 4) Sustainable enhancing agricultural production 5) Systems approaches to the biosciences 6) New strategic approaches to industrial biotechnology