Can improved genetic understanding of grain weight help feed the world?

Wheat provides 20% of the calories and protein consumed by humans. The world population will reach 9 billion by 2050, which requires food production to more than double. Increases in wheat yield are not meeting this demand though, partly because yield is a complex trait. The study of individual yield components, such as grain weight, is a promising route to solve this issue. We have recently cloned a novel allele of a transcription factor (P1) that increases thousand grain weight by 6.1%. We hypothesise that understanding the mechanisms behind this increase will allow us to further modify it and identify the best strategies to deploy it into commercial wheat varieties.

The aim of this PhD project will be to investigate the mechanism underpinning this increase in grain weight by elucidating the P1 regulatory network in polyploid wheat. To achieve this, we will study the changes in gene expression resulting from this novel allele of P1 to identify its downstream targets. This will include generating co-expression networks and testing candidate genes using available mutants. Furthermore, we have observed similar phenotypes between plants with the novel P1 allele and transgenic plants with high levels of microRNA172 (miR172). The project will investigate whether P1 and miR172 are part of the same genetic pathway or whether they act on shared targets in an independent manner and will use a series of unique genetic lines to address this hypothesis through in-depth phenotyping, microscopy and expression analyses.