Webb Group: The circadian clock as a regulator of yield traits in wheat
Supervisor
Professor Alex Webb
Brief Summary
This project investigates the molecular mechanisms by which wheat regulates the time to flower (heading). We have developed new approaches and tools to investigate the molecular mechanisms regulating this important biological pathway, which is poorly understood.
Importance of Research
Wheat is the UK’s largest crop by area. To meet the future needs of the UK, new germplasm must be identified that can be used in breeding programmes to adapt to increased demand and the change in local growing seasons resulting from climate change. We have identified some of the potential molecular mechanisms of one of the most important traits in crop biology, the photoperiodic regulation of flowering time. The molecular knowledge we will identify has the potential to provide new tools for wheat breeders.
Project Summary
The circadian oscillator is a regulator of the seasonal responses of wheat and therefore there is a need to understand to the basic biology of the circadian system in wheat to inform breeding strategies. Our new data suggest that the circadian oscillator of wheat has a different structure to that of Arabidopsis and that variation at circadian loci can affect to yield traits in the field. We have isolated over the last few years a population of wheat plants with mutations in the different genes that form part of the circadian oscillator. These mutants have shown that the molecular basis of the circadian oscillator in wheat is different to that in Arabidopsis. Particularly the ELF3 clock protein has a different role in wheat. In our latest discovery we have found that TOC1 has a key role in regulating ELF3, and therefore impacting on circadian timing and flowering in wheat. This is different to Arabidopsis where TOC1 is not a direct regulator of ELF3. We want to understand what this difference between wheat and Arabidopsis means for control of growth and flowering.
What will the successful application do?
You will isolate TILLING and TDNA mutants of TOC1 to provide tools for investigation of the roles of TOC1. Additionally you will perform bioinformatic analyses to determine if there is variation at the TOC1 loci in elite varieties and landraces and investigate their impact on the circadian rhythms and flowering and growth of wheat. You will proceed to obtaining a mechanistic insight as to the function of TOC1. This could include testing whether TOC1 represses ELF3 through qPCR and RNAseq studies in mutants and CHIPseq to test for direct binding at the ELF3 and other
promoters.
Training Provided
The student will receive training in wheat genetics, circadian biology, molecular biology and the pathway from research to field application.