Genetic regulation of senescence, nutrient remobilisation and grain protein content in wheat

Production of staple crops such as wheat must increase by 50 % to meet the food requirements of the global population which is projected to exceed 9 billion people by 2050. Wheat plays several important roles in the human diet providing 20 % of calories and 20 % of protein eaten by humankind. This dual role presents a challenge because in general there is a negative trade-off between yield and protein content. This means that when we aim to increase yield, protein content may decrease which could have an adverse effect on human nutrition. Furthermore, high protein levels are required to process wheat flour into bread, and lower protein levels would result in poor quality bread. This project focuses on understanding the molecular mechanisms governing the negative trade-off between yield and protein content. This knowledge will allow wheat varieties with improved yield and enhanced protein content to be developed.
During grain development, the plant may either continue to photosynthesise which could increase yield, or the plant may start to senesce, allowing nutrients to be remobilised from vegetative tissues into the developing grain and thus increase protein content. We have identified a set of candidate transcription factors which regulate senescence in wheat which we hypothesise will also play a role in regulating nutrient remobilisation. In this project we will investigate the roles of these transcription factors in regulating senescence and nutrient remobilisation and determine their effects on yield and grain protein content.