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

小麦提供了人类消耗的20%的卡路里和蛋白质。到2050年，世界人口将达到90亿，这就要求粮食产量增加一倍以上。然而，小麦产量的增加并不能满足这种需求，部分原因是产量是一种复杂的性状。研究籽粒重等个别产量成分是解决这一问题的一条有希望的途径。我们最近克隆了一个新的转录因子（P1）等位基因，使千粒重增加6.1%。我们假设，了解这种增长背后的机制将使我们能够进一步修改它，并确定将其部署到商业小麦品种的最佳策略。本博士项目的目的是通过阐明多倍体小麦P1调控网络来研究籽粒重量增加的机制。为了实现这一目标，我们将研究由P1的这种新型等位基因引起的基因表达变化，以确定其下游靶点。这将包括生成共表达网络和使用可用的突变体测试候选基因。此外，我们还观察到具有新型P1等位基因的植物与具有高水平microRNA172 （miR172）的转基因植物之间的表型相似。该项目将研究P1和miR172是否属于同一遗传途径的一部分，或者它们是否以独立的方式作用于共同的靶标，并将使用一系列独特的遗传系，通过深入的表型分析、显微镜和表达分析来解决这一假设。

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.