Targeted gene knockouts in crops using RNA-guided Cas9 nuclease

在开发改良作物时，植物育种者一直依赖于在种群中发现变异或变化，以确定可能为作物提供优势的特征（或遗传性状）。这种变异是由于农作物的遗传序列（DNA）随着时间的推移可能发生的变化造成的，并且是进化的正常部分（DNA突变）。这些变化可以导致许多新的特性，例如植物具有增强的抗病性或改善的营养品质。有时，所需的变异是不可用的，所以育种者使用方法来引入DNA的变化，如化学或辐射处理种子，希望在得到的植物中找到所需的变异。几十年来，这些方法已广泛用于传统植物育种。DNA序列的变化通常会导致突变，从而阻止特定基因的工作。突变作为研究工具是非常有用的，对植物育种者也很有用。如果科学家能在他们感兴趣的基因中发现突变（即产生无功能基因或基因敲除），那么他们就有办法弄清楚该基因的作用。直到最近，引入突变的方法都是非特异性的，这意味着他们可以靶向植物中的大量基因，希望包括感兴趣的DNA区域或基因。现在，我们第一次有了一种技术，可以将突变引入特定的感兴趣的基因。这被称为基因组编辑。一种名为CRISPR / Cas9的特定基因组编辑技术可以轻松靶向任何感兴趣的基因，我们已经证明这在大麦和甘蓝（西兰花）中效果良好。在这个项目中，我们将为研究界提供特定基因突变的植物。这将使一系列研究方案取得更快的进展。此外，我们将提供的资源可以导致具有理想特性的植物包括在新的作物品种中。由于这是一项非常新的技术，尚未决定如何对其进行监管。我们将在该项目中收集的数据也将帮助监管机构就基因组编辑的未来监管做出决定。

In developing improved crops, plant breeders have always depended on finding variation or changes within a population to identify characteristics (or genetic traits) that could potentially offer an advantage to the crop. This variation is due to changes that can occur in the genetic sequence (DNA) of the crop plant over time - and is a normal part of evolution (mutations in the DNA). These changes can be responsible for many new characteristics such as plants with increased disease resistance or improved nutritional quality. Sometimes the desired variation is not available so breeders have used methods to introduce changes in the DNA such as chemical or radiation treatment of seed hoping to find the required variation in the resulting plants. These methods have been widely used in conventional plant breeding for decades. Changes to the DNA sequence often leads to a mutation that stops a particular gene from working. Mutations are incredibly useful as research tools as well as useful to plant breeders. If a scientist can find a mutation in the gene that they are interest in (i.e. generating a non-functional gene, or a gene knock-out) then they have a way of working out what that gene does.Until recently, methods to introduce mutations were non-specific meaning they could target a large number of genes within the plant, hopefully including the DNA region, or gene, of interest. Now for the first time we have a technology to introduce mutations into a specific gene of interest. This is referred to as genome editing. A specific genome editing technology called CRISPR / Cas9 allows easy targeting of any gene of interest and we have demonstrated that this works well in both barley and Brassica oleracea (broccoli). In this project, we will offer to create plants with mutations in specific gene(s) of interest for the research community. This will allow more rapid progress in a range of research programmes. In addition, the resource we will offer could lead to plants with desirable characteristics to include in new crop varieties. As this technique is very new there have not yet been decisions as to how it should be regulated. The data that we will collect in this project will also help regulators to make decisions on future regulation of genome editing.