Developing nutrient-enriched cereal grains with large embryos.

开发营养丰富、胚芽大的谷物。

• 批准号: BB/T002905/1
• 负责人: Kay Trafford
• 金额: $ 56.55万
• 依托单位: National Institute of Agricultural Botany
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT002905%2F1
• 关键词: Developing; nutrient; enriched; cereal; grains

Cereal grains are composed of three main components: husk, starchy endosperm and germ. The germ (also called the embryo) accounts for only a small proportion of grain weight (2-3% in barley and wheat) but compared to the larger endosperm, it is rich in nutrients. Very often, cereal grains are processed to produce white flour which involves removing the husk and germ. However, whole grains are richer than white flour in fibre, nutrients, vitamins and minerals and there is an increasing public demand for products made from whole grains. This is because we now know that people who eat whole-grain foods have a lower risk of almost all chronic diseases. Our project aims to increase germ size, thus enhancing whole-grain quality for human health and animal nutrition. It is a partnership between cereal scientists at NIAB, Cambridge and at the James Hutton Institute (JHI) in Dundee. Our project aims to identify the factors responsible for the reduction in relative germ size that has occurred during the domestication of cereals. It has been shown that endosperm size has increased during domestication in wheat, whilst germ size has remained constant. By comparing collections of wild and domesticated grains we hope to identify when and how relative germ size became sub-optimal during the course of domestication. Identification of the genetic factors responsible for this will provide the tools needed to allow rapid breeding for improved grain quality. Studies of variants of cultivated barley and other cereals (rice and maize) have shown that it is possible to drastically increase germ size (although this is accompanied by a decrease in endosperm size). At present three genes have been discovered that control relative germ size. These are: GIANT EMBRYO (GE) in rice and maize, BIG EMBRYO 1 (BIGE1) in maize and PROLAMIN-BINDING FACTOR (PBF) in barley. We will investigate these genes and the genetic and biochemical pathways in which they work. Our aim is to find a way to increase relative germ size without causing deleterious decreases in endosperm size, grain size or yield. Of the three genes known thus far to control germ size, PBF has the most commercial potential as it impacts on barley grain development only, without any detrimental effects on plant growth. However, the negative effect on endosperm size that accompanies reductions in PBF function is greater than that seen with GE and BIGE variants. To find a way to overcome this unfavourable impact on yield, first we will test whether it is possible to separate the favourable effects of PBF on the germ from the unfavourable effects on the endosperm using genetic manipulation. We will produce a barley plant with a functional PBF protein in the endosperm but lacking functional PBF in the germ. Secondly, we will investigate the mode of action of PBF to identify germ-specific and endosperm-specific target genes. Selecting for variation specifically in these target genes will allow plant breeders to optimize relative germ size. Finally, we will build on our knowledge of the control of germ size in barley and other cereals to produce wheat with improved nutritional value. We will transfer the trait for optimal germ size to wheat by selecting for variation in the three genes known to control this in rice, barley and maize: GE, BIGE1 and PBF. We will use publicly-available germplasm resources in durum/pasta wheat and bread wheat to identify variant genes and then combine these together in different combinations. The resulting large-germ wheat will be assessed for improved grain quality. This approach provides a non-GM route to deliver wheat plants with enhanced nutritional quality.

谷物由三种主要成分组成：谷壳、淀粉胚乳和胚芽。胚芽（也称为胚胎）只占籽粒重量的一小部分（大麦和小麦的2-3%），但与较大的胚乳相比，它含有丰富的营养。通常，谷物被加工成白面粉，这需要去壳和胚芽。然而，全谷物在纤维、营养、维生素和矿物质方面比白面粉更丰富，公众对全谷物制品的需求越来越大。这是因为我们现在知道，吃全麦食品的人患几乎所有慢性疾病的风险都较低。我们的项目旨在增加胚芽大小，从而提高人类健康和动物营养的全谷物质量。这是剑桥大学NIAB和敦提詹姆斯·赫顿研究所（James Hutton Institute， JHI）的谷物科学家的合作项目。我们的项目旨在确定在谷物驯化过程中发生的相对胚芽大小减少的因素。研究表明，小麦驯化过程中胚乳大小增加，而胚芽大小保持不变。通过比较野生和驯化谷物的收集，我们希望确定在驯化过程中相对胚芽大小何时以及如何成为次优的。确定造成这种情况的遗传因素将为快速育种提高粮食质量提供所需的工具。对栽培大麦和其他谷物（水稻和玉米）变种的研究表明，有可能大幅增加胚芽大小（尽管这伴随着胚乳大小的减少）。目前已经发现了三个控制相对胚芽大小的基因。它们分别是：水稻和玉米的巨胚（GE）、玉米的大胚1号（BIGE1）和大麦的PROLAMIN-BINDING FACTOR （PBF）。我们将研究这些基因及其工作的遗传和生化途径。我们的目标是找到一种方法来增加相对胚芽大小，而不造成有害的胚乳大小，颗粒大小或产量的减少。在目前已知的三种控制胚芽大小的基因中，PBF具有最大的商业潜力，因为它只影响大麦籽粒发育，对植物生长没有任何有害影响。然而，与GE和BIGE变体相比，PBF功能降低对胚乳大小的负面影响更大。为了找到一种方法来克服这种对产量的不利影响，首先我们将测试是否有可能通过遗传操作将PBF对胚芽的有利影响与对胚乳的不利影响分开。我们将培育出一株在胚乳中含有功能性PBF蛋白而在胚芽中缺乏功能性PBF的大麦植株。其次，我们将研究PBF的作用模式，以鉴定细菌特异性和胚乳特异性靶基因。选择这些目标基因的变异将使植物育种者能够优化相对胚芽大小。最后，我们将利用我们在大麦和其他谷物中控制胚芽大小的知识来生产具有更高营养价值的小麦。我们将通过选择在水稻、大麦和玉米中控制最佳胚芽大小的三个基因（GE、BIGE1和PBF）的变异，将最佳胚芽大小的性状转移到小麦上。我们将利用公开的硬粒/面食小麦和面包小麦种质资源，鉴定变异基因，然后将这些变异基因组合在一起进行不同的组合。由此产生的大胚芽小麦将用于评价其改良的籽粒品质。这种方法提供了一种非转基因途径，使小麦植株具有更高的营养质量。

项目成果

A high-resolution single-molecule sequencing-based Arabidopsis transcriptome using novel methods of Iso-seq analysis.

• DOI: 10.1186/s13059-022-02711-0
• 发表时间: 2022-07-07
• 期刊: Genome biology
• 影响因子: 12.3

TRA1: A Locus Responsible for Controlling Agrobacterium-Mediated Transformability in Barley.

TRA1：负责控制大麦中农杆菌介导的转化性的基因座。

• DOI: 10.3389/fpls.2020.00355
• 发表时间: 2020
• 期刊: Frontiers in plant science
• 影响因子: 5.6
• 作者: Orman-Ligeza B

LYS3 encodes a prolamin-box-binding transcription factor that controls embryo growth in barley and wheat

• DOI: 10.1101/2019.12.18.880955
• 发表时间: 2019-12
• 期刊: Journal of Cereal Science
• 影响因子: 3.8
• 作者: Beata Orman-Ligeza;P. Borrill;T. Chia;Marcella Chirico;J. Doležel;Sinéad Drea;Miroslava Karafiátová;Nicole Schatlowski;C. Solomon;B. Steuernagel;B. Wulff;C. Uauy;Kay Trafford

TRA1 : a locus responsible for controlling Agrobacterium -mediated transformability in barley

TRA1：负责控制大麦中农杆菌介导的转化性的基因座

• DOI: 10.1101/2019.12.19.882274
• 发表时间: 2019
• 作者: Orman-Ligeza B