Cellular and molecular characterisation of senescence in the energy grass

There are very ambitious targets for reductions in carbon dioxide emissions and the use of renewable energy. Biomass crops have the potential to make a major contribution toward achieving these targets. Perennial grasses such as Miscanthus are highly promising bio fuel crops because they are high yielding with low inputs. For combustion in power stations Miscanthus stems are harvested dry once senescence is complete. Remobilisation of resources from aerial parts to the rhizome (below ground storage organ) and subsequent
leaching during the winter means that very little nitrogen is removed from the field. Most plant nitrogen is contained within proteins; furthermore, approximately 30% of the leaf protein is associated with chlorophyll which, during senescence, is degraded and remobilised. The loss of chlorophyll and therefore green colour is a functional marker for senescence. Senescence
with co-ordinated protein and chlorophyll breakdown is different to rapid cell death caused by late season frosts. The ability to mobilise resources via senescence before cell death processes occur is an important goal for sustainable energy crop production. The timing of senescence will impact on yield and compositional characteristics of the crop. Senescence has been extensively studied in other plant species but very little is known about this process in Miscanthus. We will use basic knowledge from other species to understand more about this important process in Miscanthus. We aim to characterise senescence in Miscanthus and determine the molecular determinants and morphological consequences of variations in natural
senescence identified in different Miscanthus genotypes. We will also characterise the mobilisation of nutrients in Miscanthus that contribute to sustainable crop production.