Production of wheat lacking B-type starch granules

缺乏B型淀粉粒小麦的生产

• 批准号: BB/J019496/1
• 负责人: Kay Trafford
• 金额: $ 46.56万
• 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: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FJ019496%2F1
• 关键词: Production; wheat; lacking; type; starch

Starch is a major component of cereal grains and its functional properties have a significant impact on grain utilisation. Of considerable importance is the size and shape of the starch granules. In wheat, barley, rye and most of their wild grass relatives, there are two types of starch granules, called A- and B-type. These differ in size, leading to a bimodal granule-size distribution that is unusual amongst plant starches and not found in other grasses, including Brachypodium, oats, rice and maize.The smaller, B-type starch granules have negative impacts on many end-uses of wheat and barley. So far, attempts to reduce or remove B-granules from these crops by breeding have failed. The reason for this is the lack of genetic variation in B-granule content between cultivars. However, there is much greater variation for this character between species of Aegilops (Goat Grass), wild grasses that include the ancestors of bread wheat. The existence of Aegilops species lacking B-granules suggests that it should be possible to introduce variation for B-granule content into the closely-related crop species.The project builds on previous work in which we identified a major QTL controlling the content of B-type starch granules in Aegilops. Our ultimate goal is to identify and manipulate the gene responsible for the control of B-granule content in wheat and barley, Bgc-1. In this project, we will investigate gene order in the region of the genome harbouring Bgc-1 and compare it with that in other grasses. If the opportunity arises within our project's timeline, we will be ready to use the latest developments from ongoing genomics projects in other labs to identify the orthologs of Bgc-1 in wheat and barley and we will begin to manipulate Bgc-1 in these crops using RNAi and TILLING technologies.Prior to the identification of Bgc-1, we will start to produce mutant wheat plants lacking B-granules using a pre-existing collection of deletion lines of a breadmaking wheat cultivar Paragon. Previously, this population has been successfully used to generate wheat mutants with novel phenotypes by stacking deletions of genes. By screening for deletions spanning the Bgc-1 region, we can select lines likely to lack Bgc-1 in each of the three genomes of wheat and then stack these into a single plant by repeated rounds of crossing and selection.This project will produce: 1) a fine map of the Bgc-1 region and possibly identification of the Bgc-1 gene in Aegilops and a comparision of this region/gene with those in other grasses. 2) near-isogenic lines of wheat and Aegilops that will allow functionality testing to determine the utility of B-granule-less grains. In addition, if Bgc-1 is identified, the production of genetically manipulated lines of wheat and barley and/or TILLING mutants lacking B-granules will be underway by the end of the project.

淀粉是谷物的主要成分，其功能特性对谷物的利用有重要影响。淀粉颗粒的大小和形状是相当重要的。在小麦、大麦、黑麦和它们的大部分野草亲戚中，有两种类型的淀粉颗粒，称为A型和b型。它们的大小不同，导致了双峰状的颗粒大小分布，这在植物淀粉中是不寻常的，在其他禾草中也没有发现，包括短柄草、燕麦、水稻和玉米。较小的b型淀粉颗粒对小麦和大麦的许多最终用途产生负面影响。到目前为止，通过育种减少或去除这些作物中的b颗粒的尝试都失败了。其原因是品种间b粒含量缺乏遗传变异。然而，这种特征在山羊草（山羊草）的物种之间有更大的差异，山羊草是包括面包小麦的祖先在内的野生草。缺乏b颗粒的盾叶草品种的存在表明，在密切相关的作物品种中引入b颗粒含量变异是可能的。该项目建立在以前的工作中，我们确定了一个主要的QTL控制的b型淀粉颗粒的含量在Aegilops。我们的最终目标是鉴定和操纵负责控制小麦和大麦中b颗粒含量的基因Bgc-1。在本项目中，我们将研究Bgc-1基因组区域的基因顺序，并与其他禾本科植物进行比较。如果在我们项目的时间表内有机会出现，我们将准备利用其他实验室正在进行的基因组学项目的最新发展来确定小麦和大麦中Bgc-1的同源物，我们将开始使用RNAi和TILLING技术在这些作物中操纵Bgc-1。在鉴定Bgc-1之前，我们将利用已有的面包小麦品种Paragon的缺失系，开始生产缺乏b颗粒的突变小麦植株。以前，这个群体已经成功地通过堆叠基因缺失来产生具有新表型的小麦突变体。通过筛选跨越Bgc-1区域的缺失，我们可以在小麦的三个基因组中选择可能缺乏Bgc-1的品系，然后通过反复的杂交和选择将这些品系堆叠到一个单一的植株中。该项目将产生：1)绘制Bgc-1区域的精细图谱，并可能鉴定出Aegilops的Bgc-1基因，并将该区域/基因与其他禾本科植物进行比较。2)小麦和Aegilops的近等基因系，这将允许进行功能测试，以确定无b颗粒谷物的效用。此外，如果Bgc-1被鉴定出来，小麦和大麦的转基因品系和/或缺乏b颗粒的TILLING突变体的生产将在项目结束时进行。

项目成果

Starch granule morphology in oat endosperm

燕麦胚乳中淀粉颗粒的形态

• DOI: 10.1016/j.jcs.2016.10.011
• 发表时间: 2017
• 期刊: Journal of Cereal Science
• 影响因子: 3.8
• 作者: Saccomanno B

Transfer of a starch phenotype from wild wheat to bread wheat by deletion of a locus controlling B-type starch granule content.

• DOI: 10.1093/jxb/erx349
• 发表时间: 2017-11-28
• 期刊: Journal of experimental botany
• 影响因子: 6.9
• 作者: Chia T;Adamski NM;Saccomanno B;Greenland A;Nash A;Uauy C;Trafford K
• 通讯作者: Trafford K

A carbohydrate-binding protein, B-GRANULE CONTENT 1, influences starch granule size distribution in a dose-dependent manner in polyploid wheat

• DOI: 10.1093/jxb/erz405
• 发表时间: 2020-01-01
• 期刊: JOURNAL OF EXPERIMENTAL BOTANY
• 影响因子: 6.9
• 作者: Chia, Tansy;Chirico, Marcella;Trafford, Kay
• 通讯作者: Trafford, Kay