Investigating the role of flavonoid biosynthesis in coat-imposed dormancy to facilitate the breeding of white-grained varieties of wheat

研究类黄酮生物合成在皮毛休眠中的作用，以促进白粒小麦品种的育种

• 批准号: BB/H012362/1
• 负责人: Andrew Phillips
• 金额: $ 63.25万
• 依托单位: Rothamsted Research
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FH012362%2F1
• 关键词: Investigating; role; flavonoid; biosynthesis; coat

The vast majority of bread consumed in the UK, whether made from white, brown or wholemeal flour, is produced from red-grained wheat. The 'red' colour of the grain (actually more of a reddish-brown) is due to the presence of coloured compounds, called flavonoids, in the seed coat. As well as colour, these flavonoids (related to the tannins found in tea and red wine) give wholemeal bread its somewhat bitter taste that is disliked by many people. For this and other cultural reasons, most bread produced in the UK and Europe is made from white flour, which has had all of the outer layers of the seed (the bran) removed during milling. However, removal of the bran results in a reduction in the nutritional quality of the grain, as much of the fibre, minerals, vitamins and other nutrients of the wheat grain are found in these outer layers. There is overwhelming evidence that consumption of wholemeal bread and wholegrain products containing these components contributes to a healthier lifestyle by offering protection against a number of diseases including diabetes, heart disease and bowel cancer. However, surveys suggest that one third of British adults and a quarter of children do not eat any wholegrain foods at all, and promotion of the health benefits of wholemeal grains has had relatively little effect on this sector of the population. White-grained wheats lack the red flavonoids of the seed coat and the associated bitter taste; wholemeal bread made from white-grained varieties has therefore been found to be more acceptable to some consumers; there also an appreciable market for wholegrain breakfast cereals, cakes and biscuits made from white wheat. Although white wholegrain products lack the health benefits imparted by the tannin components, they still contain far more fibre, micronutrients and phytochemicals than those made from refined flour. However, nearly all wheat varieties grown in the UK are of the red-grained type, as white grains are prone to germinating before harvest, a particular problem in countries such as the UK where cool, wet weather before harvest is common. This 'pre-harvest sprouting' results in a loss of grain quality and even a small proportion of sprouted grains can result a serious loss of value for the crop. For this reason, white-grained wheats are mainly grown in warmer, drier parts of the world such as Australia, necessitating the costly importation of grain by UK millers and bakers. In an existing programme that involves other academic partners as well as most of the UK's commercial wheat breeders, our colleagues are studying the underlying biology of pre-harvest sprouting. This current work is leading to the identification of UK wheat varieties that are more sprouting resistant and should provide information that will help breeders to improve their performance still further. Our new project has several aims: first, we want to develop genetic markers for the genes that confer the white grain colour, so that wheat breeders can more easily produce new white varieties with good sprouting resistance. Second, we want to establish whether breeding white grain colour into the sprout-resistant varieties identified above will generate sprouting-resistant white wheat lines that can withstand the UK's cool, wet climate. Finally, we want to explore the possibility that compounds earlier in the biochemical pathway that produces the red pigment are protective against sprouting, in which case we should be able to develop white wheats that are as sprout-resistant as red-grained varieties and also retain the antioxidant properties of the flavonoids. This project thus aims to provide the knowledge and tools to facilitate the development of white-grained wheats that can be grown reliably under UK conditions.

英国消费的绝大多数面包，无论是用白面粉、棕色面粉还是全麦面粉制成的，都是由红粒小麦制成的。谷物的“红色”颜色（实际上更多的是红棕色）是由于种皮中存在称为类黄酮的有色化合物。除了颜色之外，这些黄酮类化合物（与茶和红酒中发现的单宁有关）使全麦面包具有许多人不喜欢的苦味。由于这个和其他文化原因，英国和欧洲生产的大多数面包都是用白面粉制成的，在碾磨过程中去除了种子（麸皮）的所有外层。然而，去除麸皮会导致谷物的营养质量下降，因为小麦谷物的大部分纤维、矿物质、维生素和其他营养物质都存在于这些外层中。有大量证据表明，食用含有这些成分的全麦面包和全麦产品有助于预防糖尿病、心脏病和肠癌等多种疾病，从而有助于形成更健康的生活方式。然而，调查显示，三分之一的英国成年人和四分之一的儿童根本不吃任何全麦食品，而宣传全麦谷物的健康益处对这部分人群的影响相对较小。白粒小麦缺乏种皮的红色类黄酮和相关的苦味；因此，一些消费者发现用白粒品种制成的全麦面包更容易接受；白小麦制成的全麦早餐麦片、蛋糕和饼干也有很大的市场。尽管白色全麦产品缺乏单宁成分带来的健康益处，但它们仍然比精制面粉制成的产品含有更多的纤维、微量营养素和植物化学物质。然而，英国种植的几乎所有小麦品种都是红粒型，因为白色谷物在收获前容易发芽，这在英国等收获前凉爽潮湿天气常见的国家尤其如此。这种“收获前发芽”会导致谷物质量下降，甚至一小部分发芽谷物也会导致作物价值严重损失。因此，白粒小麦主要种植在世界上温暖、干燥的地区，例如澳大利亚，英国磨坊主和面包师需要昂贵的进口谷物。在一个涉及其他学术合作伙伴以及大多数英国商业小麦育种者的现有计划中，我们的同事正在研究收获前发芽的基础生物学。目前的这项工作正在导致英国小麦品种的鉴定，这些品种具有更强的抗发芽能力，并且应该提供有助于育种者进一步提高其性能的信息。我们的新项目有几个目标：首先，我们希望为赋予白色谷物颜色的基因开发遗传标记，以便小麦育种者可以更容易地培育出具有良好发芽抗性的新白色品种。其次，我们想要确定将白色粒色培育到上述抗发芽品种中是否会产生能够承受英国凉爽潮湿气候的抗发芽白小麦品系。最后，我们想要探索产生红色素的生化途径中较早的化合物是否可以防止发芽，在这种情况下，我们应该能够开发出与红粒品种一样抗发芽的白小麦，并且还保留类黄酮的抗氧化特性。因此，该项目旨在提供知识和工具，以促进可在英国条件下可靠种植的白粒小麦的开发。

项目成果

KnetMiner: a comprehensive approach for supporting evidence-based gene discovery and complex trait analysis across species.

• DOI: 10.1111/pbi.13583
• 发表时间: 2021-08
• 期刊: Plant biotechnology journal
• 影响因子: 13.8
• 作者: Hassani-Pak K;Singh A;Brandizi M;Hearnshaw J;Parsons JD;Amberkar S;Phillips AL;Doonan JH;Rawlings C
• 通讯作者: Rawlings C

Proanthocyanidin biosynthesis in the developing wheat seed coat investigated by chemical and RNA-Seq analysis.

• DOI: 10.1002/pld3.453
• 发表时间: 2022-10
• 期刊: Plant direct
• 影响因子: 3