Dominant cis-regulatory variation to improve quantitative traits in polyploid wheat

Urgent action is needed to sustainably intensify global crop production using science-based solutions. Across crops, selection for mutations in cis-regulatory regions of transcription factors has been at the centre of the domestication and breeding process to improve productivity traits. Further efforts to advance towards this goal, however, are hampered in the young polyploid genome of wheat as many genes are present as two or three homoeologous copies with overlapping functions. As a result, recessive variation at single loci is often masked by redundancy with homoeologous copies. This understanding, together with the recent breakthroughs in wheat genomics and gene editing approaches, allow us to now propose an innovative strategy to overcome the perennial problem of functional redundancy in polyploid wheat.The aim of this proposal is to use state-of-the-art genomics to produce a novel framework that defines the cis-regulatory landscape of the polyploid wheat genome. I hypothesise that targeting mutations to cis-regulatory regions of transcription factors will result in dominant alleles within the polyploid context. Through genome editing approaches, I will engineer novel dominant alleles that should result in an unprecedented step change in wheat phenotypic variation, with the potential to improve productivity traits. I will benchmark this novel phenotypic variation with that achieved through recessive loss-of-function mutants in the same transcription factors and their putative downstream genes. Upon completion, I will deliver publicly-accessible germplasm with unique and novel variation that will enhance wheat productivity traits beyond what is traditionally possible. This project paves the way to apply similar approaches to other polyploid crops and will demonstrate the transformational impact of innovative genetic solutions towards addressing food security.