Engineering more water-use efficient crops: functional genomics of the circadian control of CO2 fixation associated with Crassulacean acid metabolism

The world is getting hotter and drier due to climate change, and the human population is growing rapidly to the extent that it has been predicted that we will need to increase crop yields by 50 - 70 % by 2050 in order to feed the predicted 9 - 10 billion people. This extra food production has to be achieved using the same land and the same or less fresh water relative to the water used by agriculture today. Achieving such dramatic advances in crop productivity to underpin human food security this century is widely regarded as a key global grand challenge that requires ground-breaking, innovative approaches that "think outside the box". Our research aims to leverage a naturally occurring super-charged adaptation of photosynthesis called Crassulacean acid metabolism (CAM).

This adaptation can enhance plant water use efficiency well beyond that of any of today's major food crop species such as rice, wheat or maize. Through decoding the genomes and transcriptomes of model CAM species and undertaking functional genomics research in model CAM species in the genus Kalanchoë, our work is establishing the minimal parts list for the engineering of CAM into C3 crops such as rice or wheat in order to enhance crop water use efficiency and photosynthesis.

This project will work to leverage our recent discoveries by exploring the regulatory regions of genes involved in CAM using the firefly luciferase reporter gene to "see" the activity of the promoter. In particular, we seek to understand how the activity of the genes required for CAM is regulated by the endogenous circadian clock; the internal timekeeper that organisms use to optimise their biochemistry relative to the daily light/ dark cycle. This will allow the student to make a key contribution to our understanding of the genetic elements associated with CAM and its optimal temporal regulation. The student will also become accomplished in plant transformation and the techniques required for the detailed molecular, biochemical and physiological characterisation of the generated transgenic lines.