Regulation of wheat inflorescence architecture by a cation amino acid transporter

阳离子氨基酸转运蛋白对小麦花序结构的调节

• 批准号: BB/T007133/1
• 负责人: Cristobal Uauy
• 金额: $ 74.55万
• 依托单位: John Innes Centre
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT007133%2F1
• 关键词: Regulation; wheat; inflorescence; architecture; cation

An inflorescence is a group of grain-producing flowers that form on a complex arrangement of branches. Domestication and modern breeding have harnessed diversity of branch numbers and arrangements that form on an inflorescence to increase grain production, which has frequently involved modifying the activity of genes that control inflorescence development. This approach has been under-utilised in wheat as very few genes are known to regulate inflorescence architecture in this crop - we aim to identify genes that control wheat inflorescence development to help optimise yield related traits that will contribute to the 60-70% increase in global grain production required by 2050. The research proposed here will build on our group's breakthrough discovery that a mutation in a gene encoding CATION AMINO ACID TRANSPORTER1 (CAT1) dramatically effects inflorescence development in wheat, and the arrangement of branches, or spikelets, that form on the inflorescence. By deciphering the role of CAT1 during inflorescence development, the project will uncover a previously unknown role for amino acid transporters in plant reproductive biology, and will advance our understanding of molecular processes that regulate yield-related traits in cereals. We identified CAT1 as a protein that influences inflorescence architecture by performing a genetic screen to identify mutants that form an alternate arrangement of spikelets, known as 'paired spikelets'. One mutant contained mutation in the copy of CAT1 on the D genome (CAT-D1), which promotes paired spikelet development with a dominant inheritance pattern. Plants with one copy of the mutated allele (heterozygous) and two mutated copies (homozygous) form paired spikelets, and homozygous mutants display additional developmental phenotypes including severe leaf curling, additional vascular bundles (transport system within plants) and perturbed lateral root development. There is a copy of CAT1 on the B genome (CAT-B1), but not the A genome. We will investigate the amino acid transporter activity of CAT-D1 and CAT-B1 to test their functional conservation as proteins that localise to the cell membrane and transport cationic amino acids, and to assess their ability to transport the growth hormone, auxin (Objective 1). The effect of the missense mutation on CAT-D1 function will be investigated by assessing the ability of the mutant protein to transport amino acids and/or auxin, relative to the wild-type protein, using diverse experimental assays (Objective 2). We will investigate genes and molecular processes that act downstream of CAT-D1 to regulate inflorescence development by studying the involvement of auxin response pathways, which is supported by outcomes of our preliminary RNA-seq data (Objective 3). Finally, we will investigate the genetic and environmental regulation of CATD1- dependent control of inflorescence architecture by analysing the interaction between CAT1 with Photoperiod-1 and FLOWERING LOCUS T1, which are major flowering-time genes that regulate spikelet development (Objective 4). Knowledge and resources (e.g. germplasm, molecular markers) developed during the project will benefit researchers investigating molecular processes that control reproductive and developmental biology of plants, and those studying amino acid transporters in other organisms. The outputs will benefit publicly-funded and commercial breeding programmes by improving our understanding of genes that regulate inflorescence development in wheat, which will also benefit barley, rice and maize breeders. The outcomes will ultimately benefit growers and consumers by contributing to improved food security for the world's growing population, which will enhance society's quality of life and boost the UK economy.

花序是一组产生谷物的花，形成在复杂的树枝上。驯化和现代育种利用花序上形成的分支数量和排列的多样性来增加谷物产量，这通常涉及修改控制花序发育的基因的活性。这种方法在小麦中的利用率很低，因为已知很少有基因可以调节这种作物的花序结构-我们的目标是确定控制小麦花序发育的基因，以帮助优化产量相关性状，这将有助于到2050年全球粮食产量增加60-70%。这里提出的研究将建立在我们小组的突破性发现的基础上，即编码阳离子氨基酸转运蛋白1（CAT 1）的基因突变会显著影响小麦的花序发育，以及花序上形成的分枝或小穗的排列。通过破译CAT 1在花序发育过程中的作用，该项目将揭示氨基酸转运蛋白在植物生殖生物学中以前未知的作用，并将促进我们对调节谷物产量相关性状的分子过程的理解。我们确定CAT 1作为一种蛋白质，影响花序结构，通过进行遗传筛选，以确定突变体，形成一个交替排列的小穗，称为“配对小穗”。其中一个突变体（CAT-D1）在D基因组上的CAT 1拷贝中含有突变，该突变体以显性遗传方式促进成对小穗发育。具有突变等位基因的一个拷贝（杂合）和两个突变拷贝（纯合）的植物形成成对的小穗，并且纯合突变体显示额外的发育表型，包括严重的叶片卷曲、额外的维管束（植物内的运输系统）和扰动的侧根发育。在B基因组（CAT-B1）上有一个CAT 1的拷贝，但在A基因组上没有。我们将研究CAT-D1和CAT-B1的氨基酸转运活性，以测试它们作为定位于细胞膜并转运阳离子氨基酸的蛋白质的功能保守性，并评估它们转运生长激素生长素的能力（目标1）。错义突变对CAT-D1功能的影响将通过评估突变蛋白相对于野生型蛋白转运氨基酸和/或生长素的能力来研究（目的2）。我们将通过研究生长素反应途径的参与来研究作用于CAT-D1下游以调节花序发育的基因和分子过程，这得到了我们初步RNA-seq数据结果的支持（目标3）。最后，我们将调查的遗传和环境调控的CATD 1依赖控制花序结构，通过分析CAT 1与光周期-1和FLOWERDLOCUS T1，这是主要的开花时间基因，调节小穗发育（目标4）之间的相互作用。在该项目期间开发的知识和资源（例如种质，分子标记）将使研究控制植物生殖和发育生物学的分子过程的研究人员以及研究其他生物体中氨基酸转运蛋白的研究人员受益。这些成果将通过提高我们对调节小麦花序发育的基因的了解，使公共资助和商业育种计划受益，这也将使大麦、水稻和玉米育种者受益。这些成果最终将使种植者和消费者受益，为世界不断增长的人口提供更好的粮食安全，这将提高社会生活质量，促进英国经济发展。

项目成果

A wheat chromosome segment substitution line series supports characterisation and use of progenitor genetic variation

小麦染色体片段替换系系列支持祖遗传变异的表征和使用

• DOI: 10.1101/2022.06.18.496684
• 发表时间: 2022
• 作者: Horsnell R

A scalable phenotyping approach for female floral organ development and senescence in the absence of pollination in wheat.

• DOI: 10.1242/dev.200889
• 发表时间: 2022-09-15
• 期刊: Development (Cambridge, England)

MicroRNA-resistant alleles of HOMEOBOX DOMAIN-2 modify inflorescence branching and increase grain protein content of wheat.

• DOI: 10.1126/sciadv.abn5907
• 发表时间: 2022-05-13
• 期刊: Science advances
• 影响因子: 13.6

A scalable phenotyping approach for female floral organ development and senescence in the absence of pollination in wheat

小麦无授粉情况下雌性花器官发育和衰老的可扩展表型分析方法

• DOI: 10.1101/2022.04.01.486528
• 发表时间: 2022
• 作者: Millan-Blanquez M

Delayed development of basal spikelets in wheat explains their increased floret abortion and rudimentary nature

小麦基部小穗发育延迟解释了其小花败育和发育不良的增加

• DOI: 10.1101/2023.02.17.528935
• 发表时间: 2023
• 作者: Backhaus A