Project set to explore biofuel potential of desert plants

According to a statement, the five-year project funded by the US Department of Energy will explore the genetic mechanisms of crassulacean acid metabolism (CAM), or nocturnal photosynthesis, a process exhibited by certain desert plants and first discovered at Newcastle University in the 1950s.



Most plants photosynthesise during the day but CAM plants take up carbon dioxide at night, allowing them to close their pores — or stomata — during the day and reduce water loss.



Taking in CO₂ at night, the CAM plants build up a store of carbon, which is used to power photosynthesis during the day, and it is this property that enables CAM plants such as the prickly pear and agave to live in some of the world’s harshest environments.



UK lead Dr Anne Borland, a reader in molecular plant physiology at Newcastle University, said the aim was to further develop our understanding of these plants with a view to redesigning biofuel crops that could be grown on economically poor agricultural land.



‘The long-term goal of the proposed research is to enhance plant adaptability to hotter, drier climates,’ said Borland.



‘CAM species such as agave and pineapple can grow and thrive with about 20–40cm of precipitation a year, far less than the 50–100cm per year required for current biofuel feedstocks.



‘Ultimately, the aim is to introduce CAM-like properties into fast-growing species such as the poplar, enabling it to take up CO₂ at night and subsequently process this carbon during the day while the leaf pores remain closed.



‘If successful, our research could lead to poplar that requires up to 80 per cent less water for biomass production and consequently will be able to grow in more marginal habitats. In the longer term, the research has the potential to help tackle food security by maintaining the productivity of food crops in the drier and warmer world that climatologists predict for the next 60 years.’



The principal investigators on the UK-US project are Dr John Cushman (project director) at the University of Nevada, Reno; Xiaohan Yang at Oak Ridge National Laboratory; and James Hartwell at Liverpool University. 



‘With climate change predictions of a 3.8ºC increase in temperature, a drop in reliable rainfall for many parts of the world and a greater need for sources of biofuels for transportation, these biodesign approaches to enhancing biomass production become very important,’ said Cushman.



In order to identify the optimal ‘parts list’ for introducing CAM-like properties into other plants, the team will undertake research on a diverse range of plants that use CAM, with the goal of identifying the key genes and proteins required to make this photosynthetic adaptation work efficiently.



The work is funded through the US Department of Energy’s Office of Biological and Environmental Research, Genomic Science: Biosystems Design to Enable Next-Generation Biofuels.