Wheat floral organ size and its effects on grain size

各种形式的小麦(例如面包、意大利面和饼干)占全球人类消耗的卡路里的20%以上。小麦还提供了超过20%的蛋白质摄入量，超过了所有肉类来源的总和。这意味着地球上的每个人每天都要消耗近50种小麦植株的谷物。由于(城市)人口的增加和饮食习惯的改变(更多使用小麦作为动物饲料的肉制品)，对小麦的需求增加。在气候变化的背景下，我们迫切需要利用以科学为基础的解决方案可持续地加强全球小麦生产。这项提议旨在产生科学知识，用于提供遗传解决方案，以提高农民的产量。作物产量是一个复杂的性状，因为它受许多基因控制，而且还受环境的影响，类似于人类的智力。为了在理解产量方面取得进展，我们研究了产量的各个组成部分，即给定地区的小麦穗数、每穗粒数和每粒粒的重量。我们特别关注谷粒重量，因为它是最稳定的遗传性状，这意味着我们可以通过遗传解决方案实现更大的改进。每个穗内的每个小麦籽粒都被影响其最终大小的结构所包围，并与其最终重量相关。著名的植物学家林奈于1762年首次描述了一些被称为波兰小麦的小麦类型，它们具有非常长的花结构，导致了非常长的籽粒。我们已经证明，将这一特征转移到英国品种可以增加6%以上的粒重。我们最近发现了一个控制长花结构和粒型性状的基因的有力候选者。这个基因是一种转录因子，这意味着它可以开启和关闭其他基因。这表明，它协调了花和谷物的发育。我们比较了来自波兰小麦和英国小麦品种的基因，发现两个版本的基因几乎完全相同，除了一个很小的区域，这很可能影响转录因子的活性方式和位置。我们假设改变转录因子的开启地点和时间会影响小麦最终的粒重。在这个项目中，我们将确定转录因子如何影响花的结构和籽粒大小。我们将首先准确地确定该基因在英国和波兰小麦中的表达地点和时间。我们将使用最新的成像技术，如CT扫描(就像人类的CAT扫描仪)，来观察穗的内部，并确定波兰小麦的花结构和颗粒是如何变大的(更多的细胞，更大的细胞，等等)。我们将使用创新的方法来精确地确定更大的颗粒是拥有更大的花结构的直接影响，还是我们是否可以获得更大的颗粒而与它们的大小无关。我们将描述英国小麦和波兰小麦之间不同的基因的小区域，以确定这种微小的差异如何导致对籽粒大小的戏剧性影响。这将有助于识别可能开启或关闭转录因子的其他蛋白质。最后，我们将使用基因组技术来确定哪些基因被转录因子在花结构和籽粒中关闭和打开。这种深入的了解将使我们能够提出最基本的方法来提高产量，不仅在小麦中，而且在其他作物如水稻中也是如此，这些作物的颗粒大小受到相同的花器官的限制。我们将继续与育种公司对话，以确保迅速掌握这些知识，并将其转移到英国的品种中。我们还将与国际合作伙伴合作，确保知识在世界范围内传播。通过这种方式，我们的目标是提供将对全球人类产生影响的基因解决方案。

Wheat in its diverse forms (for example bread, pasta, and biscuits), accounts for over 20% of the calories consumed by humans globally. Wheat also provides over 20% of protein intake, more than all meat sources combined. This means that every person on the planet consumes the grains of almost 50 wheat plants per day, every day. There is an increased demand for wheat driven by the increase in (urban) population and the changes in dietary habits (more meat derived products which use wheat as animal feed). In the backdrop of a changing climate, it is imperative and urgent that we intensify global wheat production sustainably using science-based solutions. This proposal aims to generate scientific knowledge which will be used to deliver genetic solutions to improve yield in farmers' fields.Crop yield is a complicated trait to study given that it is controlled by many genes and it is also affected by the environment, similar to intelligence in humans. To make progress towards understanding yield, we study its individual components, namely the number of wheat spikes in a given area, the number of grains in each spike, and the weight of each individual grain. We specifically focus on grain weight as it is the most stably inherited trait, meaning we can achieve greater improvements through genetic solutions.Each wheat grain, within each spike, is surrounded by structures which affect its final size and are correlated with its final weight. Some wheat types, called Polish wheat that were first described by the famous botanist Linnaeus in 1762, have very long flower structures that lead to very long grains. We have shown that transferring this feature to UK varieties increases grain weight by over 6%.We have recently identified a strong candidate for the gene controlling the long flower structure and grain size trait. This gene is a transcription factor, meaning that it turns other genes on and off. This suggests that it coordinates how flowers and grains develop. We compared the gene from Polish wheat with UK wheat varieties and found that the two versions of the gene were almost identical, apart from a small region which most likely affects how and where the transcription factor is active. We hypothesise that changing where and when this transcription factor is turned on affects the final grain weight in wheat.In this project we will determine how the transcription factor affects flower structures and grain size. We will first determine precisely where and when the gene is expressed in UK and Polish wheat. We will use the latest imaging techniques, such as CT scans (like CAT scanners for humans), to look inside the spike and determine how the flower structures and the grains become bigger in Polish wheat (more cells, larger cells, etc). We will use innovative methods to precisely define if the larger grains are a direct effect of having larger flower structures, or if we can achieve larger grains independent of their size. We will characterise the small region of the gene which is distinct between UK and Polish wheat to define how this small difference leads to the dramatic effects on grain size. This will help identify other proteins that might turn the transcription factor on or off. Finally, we will use genomic technology to identify which genes are turned off and on by the transcription factor across flower structures and grains.This in-depth understanding will allow us to come up with the most rationale approaches to improve yield, not only in wheat, but also in other crops such as rice whose grain size is restricted by the same floral organs. We will continue our dialogue with breeding companies to ensure this knowledge is taken up swiftly and transferred into UK varieties. We will also work with international partners to ensure that the knowledge is spread worldwide. In this way, we aim to deliver genetic solutions that will impact globally on humankind.