Maximizing the potential for sustainable and durable resistance to the wheat yellow rust pathogen

研究背景小麦提供了我们每天消耗的大约20%的卡路里和蛋白质，是许多发展中国家的主要主食。随着世界人口的持续增加，必须通过尽量减少病原体造成的损失来提高小麦产量的可持续性。由条锈菌(Puccinia striiformis，PST)引起的小麦黄锈病，最近被称为小麦最大的天敌之一，仍然是全球粮食安全的主要威胁。该病是小麦生产的一个历史和持续的威胁，能够显著降低小麦品质和产量的敏感品种。21世纪初，新的、更具攻击性的PST菌株的出现和迅速传播，对全球小麦生产构成了越来越大的威胁，并导致了近年来严重的产量损失。抗击黄锈病最经济和环境可持续的方法是开发出对这种疾病具有遗传抗性的小麦品种。到目前为止，科学家和育种者已经在农业中部署了抗性基因，但对病原体将如何适应或响应它们知之甚少或一无所知。这种天生的“盲目”和低效的方法意味着，随着时间的推移，几乎没有基因仍然有效地控制这种疾病。基本上，我们对病原体的生物学和特征缺乏了解，这意味着我们一直在背后绑着一只手战斗。目的和目的最近测序技术的创新，再加上对其他物种病原体的了解增加，为我们提供了前所未有的机会，开始了解是什么使黄锈病成为一种如此毁灭性的疾病。我们建议使用这些新技术来获取多个黄锈菌菌株的完整DNA序列。我们将对来自非洲、印度和英国的最新PST菌株进行测序，并通过对历史上收集的黄锈病进行测序来追溯到过去。到目前为止，这些菌株一直保存在寒冷的环境中，它们讲述了病原体在历史上如何变化，变得更具攻击性，并战胜了当时被认为具有抗药性的小麦品种。测序将使我们能够在DNA水平上识别这些变化。理解和解释这些变化将提供小麦品种和真菌如何在三大洲共同进化的背景。这些信息将构成一个非常强大的框架，以识别小麦基因，这些基因在未来更有可能保持对黄锈病的抗性。我们将利用这些知识来鉴定并将新的抗条锈源引入适应不同环境的现代小麦品种。通过这项工作，我们还寻求在研究人员之间建立新的伙伴关系，并增强所有合作伙伴的科学能力。潜在的应用和好处这个项目将提供对小麦黄锈病病原菌如何进化以克服以前有效的小麦抗性基因的洞察，并利用这些信息为未来制定更可持续的策略。我们将与当地育种人员合作，部署这些新的抗性基因，这将导致开发出具有更好潜力的本地适应小麦品种，以在农民的田地中保持抗性。这些改良品种将从社会、经济和环境角度产生深远影响。这些品种应改善粮食作物生产系统的可持续性，并通过降低作物歉收风险、增加利润、减少杀菌剂的使用、保护产量和延长农民采用的品种的寿命，为减轻小农的饥饿和贫困作出贡献。这些品种最终应转化为增加粮食安全和增加农民收入的机会。

Context of the researchWheat provides approximately 20% of the calories and protein we consume each day and is a major staple across much of the developing world. As the world population continues to increase, the sustainability of wheat yields must be improved by minimizing losses produced by pathogens. Wheat yellow rust, caused by the fungus Puccinia striiformis (Pst), was recently dubbed one of "wheat's worst enemies" and continues to be a major threat to global food security. This disease is an historical and continuing threat to wheat production, capable of significant reductions in both grain quality and yield in susceptible varieties. The appearance of new and more aggressive Pst strains at the beginning of the 21st century and their rapid spread pose an increasing global threat to wheat production, and have resulted in severe yield losses in recent years. The most economic and environmentally sustainable way to fight yellow rust is by developing wheat varieties that are genetically resistant to the disease. To date, scientist and breeders have deployed resistance genes into agriculture, but with little or no knowledge as to how the pathogen will adapt or respond to them. This inherently 'blind' and inefficient approach has meant that few genes have remained effective in controlling the disease over time. Basically our lack of knowledge of the pathogen's biology and characteristics has meant that we've been fighting with one hand tied behind our backs. Aims and objectives Recent innovations in sequencing technologies, combined with increased knowledge of pathogens in other species, provide us with the unprecedented opportunity to start understanding what makes yellow rust such a devastating disease. We propose to use these new technologies to access the complete DNA sequence of multiple strains of the yellow rust pathogen. We will sequence the most current Pst strains from Africa, India and the UK and also go back in time by sequencing historic collections of yellow rust. These strains, which until now have been stored in the cold, tell the story of how the pathogen has changed in history to become more aggressive and overcome wheat varieties that were thought at the time to be resistant. Sequencing will allow us to identify these changes at the DNA level. Understanding and interpreting these changes will provide the context of how wheat varieties and the fungus have co-evolved across three continents. This information will constitute a very powerful framework to identify wheat genes that will stand a better chance at maintaining their resistance against yellow rust in the future. We will use this knowledge to characterize and introduce new sources of yellow rust resistance into modern wheat varieties which are adapted to the different environments. Through this work, we also seek to create new partnerships between researchers and enhance the scientific capabilities of all partners. Potential applications and benefitsThis project will provide insight into how the wheat yellow rust pathogen has evolved to overcome previously effective wheat resistance genes and use this information to develop more sustainable strategies for the future. We will work with local breeders to deploy these new resistance genes which will lead to the development of locally adapted wheat varieties with improved potential to maintain resistance in farmers' fields. These improved varieties will have profound implications from a social, economic and environmental perspective. These varieties should improve the sustainability of food crop production systems and contribute to the alleviation of hunger and poverty of small-holder farmers by reducing the risk of crop failure, increasing profit margins, reducing fungicide applications, protecting yield, and extending the life of varieties which farmers have adopted. These varieties should ultimately translate into increased food security and opportunities to improve farmer income.