Decoding gene expression in polyploid wheat

解码多倍体小麦的基因表达

• 批准号: 2748533
• 金额: --
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2748533
• 关键词: Decoding; gene; expression; polyploid; wheat

Many globally important crops are polyploids, for example cotton, sugar cane, potato and wheat. However, the regulation of polyploid genomes is complicated because there are multiple copies of most genes. We have limited knowledge about the molecular mechanisms regulating these gene copies. In this project we will take advantage of the recent revolution in wheat genomics to study how multiple gene copies are regulated polyploid genomes using wheat as a model system. The most widely grown wheat is hexaploid bread wheat (Triticum aestivum) which has on average three highly similar copies of every gene (homoeologs). The A, B and D homoeologs of each gene are typically >95% identical within coding sequences and can be functionally redundant, i.e. if one homoeolog is mutated no phenotypic effect will be observed due to compensation by the other homoeologs. However, we do not know how common functional redundancy is between homoeologs or understand the molecular mechanisms controlling redundancy. This lack of knowledge limits our ability to control phenotype and hence improve polyploid crops. Homoeolog expression levels were studied as a first step towards understanding homoeolog redundancy and it was found that 30% of wheat genes show different expression levels between the A, B and D homoeologs suggesting that the homoeologs may be non-redundant. The hypothesis is that the ability to manipulate the relative expression levels of homoeologs may provide a route to reduce functional redundancy and more easily alter phenotypes in wheat. Therefore, this project will investigate the mechanisms that control homoeolog expression levels including epigenetic and nonsense-mediate decay pathways, and their effects on phenotype.

许多全球重要的作物是多倍体，例如棉花、甘蔗、马铃薯和小麦。然而，多倍体基因组的调控是复杂的，因为大多数基因都有多个拷贝。我们对调控这些基因拷贝的分子机制了解有限。在这个项目中，我们将利用小麦基因组学的最新革命来研究多个基因拷贝是如何以小麦为模型系统调节多倍体基因组的。最广泛种植的小麦是六倍体面包小麦（Triticum aestivum），平均每个基因有三个高度相似的拷贝（同源）。每个基因的A、B和D同源物在编码序列内通常>95%相同，并且可以是功能冗余的，即如果一个同源物突变，则由于其他同源物的补偿，将观察不到表型效应。然而，我们不知道同源物之间的功能冗余有多普遍，也不了解控制冗余的分子机制。这种知识的缺乏限制了我们控制表型从而改良多倍体作物的能力。作为理解同源同源物冗余的第一步，研究了同源物表达水平，并且发现30%的小麦基因在A、B和D同源物之间显示出不同的表达水平，这表明同源物可能是非冗余的。该假说认为，操纵同源基因的相对表达水平的能力可能提供一种途径，以减少功能冗余，更容易改变小麦的表型。因此，本项目将研究控制同源基因表达水平的机制，包括表观遗传和无义介导的衰变途径，以及它们对表型的影响。