The UK is committed to an 80% reduction in CO2 emissions by 2050 as a result of the Climate Change Act (2008). Plants have been recognised as playing a pivotal role in helping to achieve such a target and the Energy Technologies Institute have estimated that the costs of the UK energy system would be up to £44 billion higher per year without bioenergy. Miscanthus belongs to a unique group of grasses which exhibit C4 photosynthesis and are capable of both extremely high yields and extreme environmental stress tolerance. Miscanthus has the highest output to input energy ratio for biomass production of any plant species because of its highly efficient photosynthesis and nutrient recycling; and is therefore an ideal feedstock for industrial biotechnology and bioenergy. The aim of our project is to gain detailed mechanistic understanding of the biological traits that underpin the development of climate proof Miscanthus crops, resilient to environmental stresses. Collectively, detailed understanding of the cellular and molecular mechanisms associated with domestication, biomass yield productivity and stress tolerance, will allow us to accelerate domestication and define future Miscanthus ideotypes for different UK environments and end-uses.
Domestication: The increased need for climate proof crops is driving a need for integration of diversity into existing crops and the novel domestication of plant species. Miscanthus is an outcrossing perennial genus, with high performing genotypes being the result of wide hybridisation and often polyploidisation. In Miscanthus we will therefore study the very early processes of domestication and the consequences of different genomes coming together, including the role of epigenetics and heterosis.
Biomass yield components: Miscanthus exhibits a number of characteristics which combine to result in high biomass productivity. We will focus on understanding the genetic and physiological control of early season growth and late season senescence contributing to the high radiation use efficiency. Building on multi-year field phenotyping of 1000 plants and genotyping-by-sequencing), we will identify quantitative trait loci and genes associated with key traits. Exemplar plants will be used in controlled environment experiments to determine the base temperature for growth, and its effect on bud morphology, metabolites and transcripts.
Stress tolerance and environmental change: Resilience requires plants and crops to be tolerant to multiple stresses at different life stages, and Miscanthus as a long season perennial is an excellent system in which to study tolerance to multiple stresses, e.g. summer drought followed by winter waterlogging, and the epigenetic memory of stress exposure. We will compare photosynthetic performance of parents and hybrids under temperature, water and nutrient stresses.
Defining of energy crop ideotypes: Successful ideotypes, identified using data from the science described above, will be used to update an existing process model. The model will be used to test for resilience under different climate scenarios and to understand the potential sensitivities attributable to different traits within the ideotype.
The overall aim of our project is to gain detailed mechanistic understanding of the biological traits that underpin the development of climate proof Miscanthus crops, resilient to environmental stresses. The three main inter-related research questions we have are:
1. What are the genetic features underpinning early domestication processes in Miscanthus?
2. What are the genetic and physiological mechanisms that control early season growth and late season senescence?
3. What are the molecular and physiological mechanisms that can make Miscanthus resilient to different environmental stresses (drought, flooding, temperature, nutrient limitation)?
The project is ongoing and we are making progress on the above particularly in relation to 1 and 2 above from knowledge gained on Miscanthus physiology, biochemistry and genetics in the field and under controlled environments including within the National Plant Phenomics facility in Aberystwyth.