Dr James Hartwell Ph.D., B.Sc. (Hons)

Our main research aims to understand the molecular biology, biochemistry and physiology of the metabolic adaptation of photosynthesis called Crassulacean acid metabolism (CAM), which is found in plants that inhabit arid and semi-arid regions of the world. We are collaborating with scientists in the USA to decode the transcriptomes and genomes of a range of CAM species, including Kalanchoë fedtschenkoi, Kalanchoë laxiflora and Agave sisalana, using next generation DNA sequencing approaches. K. laxiflora is our main functional genomics model for CAM, as we have developed a simple stable transformation system that allows us to test gene function in planta; plus this species produces thousands of tiny seeds making it very amenable to traditional genetic approaches. Our goal is to identify and characterise the 'CAMome', the genes required for efficient operation of CAM, including gaining a detailed understanding the genes required for optimal circadian clock control of CAM. We are also using RNAseq transcriptome analysis to identify and characterise the genes that underpin inverse stomatal control associated with CAM, whereby stomata open in the dark for primary CO2 fixation and close during the light allowing secondary CO2 refixation at high efficiency whilst minimising water loss.
To transition this work from models to crops, we are collaborating with international partners as part of a plant synthetic biology project involving Prof. John Cushman (University of Nevada-Reno, USA), Prof. Anne Borland (University of Newcastle), Dr. Xiaohan Yang (Oak Ridge National Lab, USA). Our lab in Liverpool is focussing on the identification of the 'parts list' or 'genetic blueprint' for CAM that will allow CAM to be engineered into C3 crops. The goal is to develop C3 crops that have the water use efficiency benefits of CAM and that are therefore suited to productive growth in semi-arid environments or in regions that suffer from prolonged seasonal drought. Moreover, we are seeking to develop novel varieties of staple crops that are pre-adapted to the expected more frequent droughts and extreme temperature events due to human-induced climate change.

This research project involves an international collaboration with Prof. Luciano Freschi and Dr. Renata Callegari-Ferrari of the University of São Paulo in Brasil. We have used quantitative RNA-seq analysis to decipher the transcriptome changes that accompany the transition from Portulaca oleracea using C4 photosynthesis when well-watered, through to CAM when drought stressed. This work has been supported by a Royal Society Newton Advanced Fellowship awarded to Prof. Freschi and support from FAPESP in Brasil for the PhD of Dr. Callegari-Ferrari.