IDENTIFICATION OF GENES ESSENTIAL FOR FREEZING TOLERANCE AS TARGETS FOR MANIPULATION IN CROPS

鉴定抗冻性必需的基因作为作物调控的目标

• 批准号: BB/J007331/1
• 负责人: Marc Knight
• 金额: $ 52.49万
• 依托单位: Durham University
• 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%2FJ007331%2F1
• 关键词: IDENTIFICATION; GENES; ESSENTIAL; FREEZING; TOLERANCE

Many plants from the world's cooler regions, including the UK, can survive winter conditions due to a process known as cold acclimation. Gardeners may be familiar with this as "cold hardening", the phenomenon whereby plants grown in cold but not frosty conditions in the autumn become better prepared for the subsequent freezing temperatures of winter and are more likely to survive. Plants that are not able to do this are usually killed by winter frosts. For crop plants this causes major yield losses.With an ever growing world population, it is estimated that food production will have to increase by 70% over the next 40 years. To achieve this we need both better yielding crops and crops that can survive the onslaughts of our environment. Freezing conditions during winter are responsible for severe crop losses in many regions of the world, including the UK. Enabling crop plants to improve their tolerance of adverse environmental conditions such as frost would provide benefits to agriculture, meaning that crops can be grown during parts of the year that would otherwise be too cold for them to survive, and allowing crops to be grown in areas that can currently not be used, for instance at higher altitudes and in colder areas.Like humans, plants have thousands of genes that determine their characteristics and what they can and cannot do. Unlike us, plants cannot move away from unfavourable environments so many of their genes are involved in helping them defend themselves against the potentially damaging conditions they experience. Every gene, whether human or plant, is "switched on" when needed. When genes are switched on they make useful proteins, natural chemicals each with a unique function. Plants that are capable of cold acclimation can survive frosts because they have genes that, when switched on, produce proteins whose role is to protect against freezing conditions. Interestingly, these proteins are also often powerful protectants against drought. Therefore, discovering the identity of such genes is the first step in helping to make crops more tolerant of cold and drought. We will discover new genes for freezing tolerance by comparing the genetic make-up of plants that can tolerate freezing with that of plants that cannot. Exciting new technology of the type used in the human genome project now allows us to examine the entire genetic code (all of the DNA that makes up the genes) of a plant so that we can look for differences in the genetic code of tolerant and susceptible plants. Finding differences in the DNA will show us the genes that are responsible for the survival of tolerant plants. When these genes are switched on they will make protective proteins; testing where in the plant these proteins are found will give us information as to the role they play in protecting it. If the proteins are important for protection, we might expect that plants producing them in larger amounts would be more tolerant, therefore we will test to see if this is indeed the case.We will perform these experiments in a model lab plant that grows quickly and is easy to study, allowing us to make more progress in a shorter time. When we have discovered which genes are most important for freezing and drought tolerance, we will apply this knowledge to a crop plant: we will produce wheat plants that make these proteins in greater abundance and we will test whether or not the plants we have produced can better withstand freezing and drought conditions. If this is successful, the information we have generated will be of benefit to crop biotechnologists and traditional breeders attempting to make more frost- and drought-resistant varieties of food crops.

来自世界较冷地区（包括英国）的许多植物可以通过一种称为冷驯化的过程在冬季条件下生存。园丁们可能熟悉这种现象，称为“冷硬化”，这种现象是指秋季在寒冷但非霜冻条件下生长的植物能够更好地为随后的冬季冰冻温度做好准备，并且更有可能生存。无法做到这一点的植物通常会被冬季霜冻杀死。对于农作物来说，这会造成严重的产量损失。随着世界人口的不断增长，预计未来 40 年粮食产量将增加 70%。为了实现这一目标，我们既需要产量更高的作物，也需要能够经受环境冲击的作物。冬季的冰冻条件导致包括英国在内的世界许多地区农作物严重损失。使作物能够提高对霜冻等不利环境条件的耐受力将为农业带来好处，这意味着作物可以在一年中太冷而无法生存的部分时间生长，并允许作物在目前无法使用的地区生长，例如在更高的海拔和较冷的地区。像人类一样，植物有数千个基因决定它们的特征以及它们能做什么和不能做什么。与我们不同，植物无法摆脱不利的环境，因此它们的许多基因都参与帮助它们抵御所经历的潜在破坏性条件。每个基因，无论是人类还是植物，都会在需要时“打开”。当基因启动时，它们会产生有用的蛋白质和天然化学物质，每种物质都具有独特的功能。能够适应寒冷环境的植物能够在霜冻中生存，因为它们的基因在开启时会产生蛋白质，其作用是防止冰冻条件。有趣的是，这些蛋白质通常也是抵御干旱的强大保护剂。因此，发现这些基因的身份是帮助作物提高耐寒和耐旱能力的第一步。通过比较能够耐受冷冻的植物和不能耐受冷冻的植物的基因组成，我们将发现新的耐受冷冻的基因。人类基因组计划中使用的令人兴奋的新技术现在使我们能够检查植物的整个遗传密码（构成基因的所有 DNA），以便我们可以寻找耐受植物和易感植物遗传密码的差异。寻找 DNA 中的差异将向我们展示负责耐受性植物生存的基因。当这些基因被打开时，它们会产生保护性蛋白质；测试这些蛋白质在植物中的位置将为我们提供有关它们在保护植物方面所发挥的作用的信息。如果这些蛋白质对于保护很重要，我们可能会期望大量产生它们的植物会更具耐受性，因此我们将进行测试，看看情况是否确实如此。我们将在生长迅速且易于研究的模型实验室植物中进行这些实验，使我们能够在更短的时间内取得更多进展。当我们发现哪些基因对于耐冻和耐旱最重要时，我们将把这些知识应用到农作物上：我们将生产出更丰富的这些蛋白质的小麦植物，我们将测试我们生产的植物是否能够更好地抵御冰冻和干旱条件。如果成功，我们生成的信息将有益于作物生物技术学家和传统育种者尝试培育更多抗霜冻和抗旱的粮食作物品种。