description
- Genetic recombination is the major driver for the creation of new varieties, but in barley and other large genome cereals, the number of recombination events is limited and mainly located towards the ends of the chromosomes. An ability to increase and/or modulate recombination in these crops would potentially accelerate the improvement of commercially important traits with minimum costs to breeders. Recent works have highlighted several mutations in genes such as FANCM, RECQ4, and HEI10, that increase recombination in Arabidopsis. Taking advantage of the new barley genomic resources, a large collection of meiotic mutants and super resolution microscopy, I have found differences between Arabidopsis and barley (as well as wheat), suggesting that large genome plants have a different level of control over recombination events, perhaps due to their size and complex genome organisation. I recently identified a novel E3 ubiquitin ligase that I called STICKY TELOMERES 1 (HvST1) that in homozygous mutants exhibits disturbed meiosis but also, and somewhat surprisingly, a dramatic increase in effective recombination of around 50% in all chromosomes. I have identified orthologues of HvST1 in wheat, rice and Brachypodium but not in Arabidopsis, suggesting that a potentially novel recombination pathway or component pathway exists in the cereals. In this proposal, I combine a range of experimental approaches that focus on investigating and characterising the role of this novel E3 ubiquitin ligase in meiosis. This research will help elucidate the first known mechanism controlling recombination by a novel ubiquitin pathway in barley and promises to reveal a new way to modulate recombination in large genome crops.