Engineering C4 photosynthesis in C3 Arabidopsis thaliana

Abstract
The human population is growing exponentially, however the growth in the production of food required to feed this population is not keeping pace. To ensure global food security, staple crop plants need to be altered to produce a higher yield, and engineering photosynthesis is widely regarded as one way in which yield potential may be increased. Most plants, including important crops such as rice and wheat, undertake C3 photosynthesis: the most common form of carbon fixation on Earth. Approximately 3-4% of plant species perform a more efficient form of photosynthesis, termed C4, whereby the photosynthetic reactions are compartmentalised spatially within the leaf, improving carbon fixation efficiency. C4 plants are particularly more efficient under warmer, drier conditions, and thus with global warming heating up the planet, and climate change resulting in the more frequent occurrence of extreme heat and drought events, engineering C3 plants to perform C4 photosynthesis has become a target of multiple crop engineering efforts. This project proposes to contribute towards this goal by taking an innovative approach to C4 engineering in the model C3 plant Arabidopsis thaliana. Specifically, this project will attempt a novel rational engineering strategy, inspired by C4 evolution, that transitions Arabidopsis from C3 to C4 photosynthesis in a stepwise fashion using a combination of genetic modification and genome editing. If successful, this project will provide new insight into photosynthetic function in Arabidopsis and may provide a blueprint for engineering C4 photosynthesis into globally important C3 crop plants.
BBSRC priority areas
This proposed research is relevant to the BBSRC theme 'Bioscience for sustainable agriculture and food' and specifically addresses the BBSRC priority area 'Food, nutrition and health,' as well as the cross-council priority 'Global food security.'