RESEARCH-PGR: Exploring the genetic and mechanistic bases of quantitative disease resistance in maize

据估计，植物病害每年造成全球作物产量损失13%，降低了收入和食品质量/安全。寄主抗病性是控制植物病害最有效的方法。定量抗病通常是持久的，通常对所有病原体变异都有效，因此是一种有效的疾病管理工具。这一建议旨在提高从基因到整个植物水平的权衡等多个层面对定量抗病的理解。这项研究将集中在玉米的一些最重要的疾病上。这一提议的广泛影响是双重的。首先，拟议的研究将确定玉米的抗病机制，玉米既是植物数量遗传学的模式物种，也是美国最有价值的作物。这些结果直接关系到正在进行的玉米和其他重要作物品种的遗传改良。第二个影响是通过在研究活动中对学生和博士后学者的培训，以及在推广活动中对高中生和教师的教育。这包括与北卡罗莱纳州立大学的专业教育机构“科学之家”合作。北卡罗莱纳州立大学将参与并提供资金，继续和更新一个成功的植物育种和遗传学研讨会，该研讨会每年为科学教师举办一次，从2013年到2019年，并参加一个面向高中生的农业发现住宿营。此外，研究人员将通过伊利诺伊大学的4-H伊利尼夏季学院和发现ace中的STEM来吸引高中生。定量抗病（QDR）是玉米和其他作物最重要的抗病形式。本研究小组和其他人之前的工作表明，QDR是基于多种基因和机制的，其中大部分尚未被理解。一些与玉米多种病害抗性相关的数量性状位点和基因已经被发现和鉴定。为了进一步分析抗病性以及其他性状，已经开发了大量的近等基因系（NILs），并对几种疾病的抗性进行了评估。本研究旨在利用和开发这些数据和资源，以扩大对QDR的认识，并将重点放在以下四个目标上：1)开发NIL群体作为玉米遗传学界的资源；2)研究QDR及其机制基础和相关的多效性；3)利用显微技术研究玉米维管病抗性的机理基础；4)利用精细定位和基因编辑技术鉴定QDR致病基因。这项工作将采用整合遗传学、基因组学、转录组学、组织学、病理学/微生物学、定量遗传学、实地研究和CRISPR介导的基因编辑的综合方法。该项目的成功完成预计将导致鉴定关键基因、机制和权衡，从而为在作物中部署定量抗病能力提供信息。由于正在研究的许多玉米机制可能广泛适用，因此拟议的工作将最终有助于全面了解QDR，重点是将其应用于提高作物产量和抗灾能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plant diseases cause an estimated 13% loss of global crop yields annually, reducing incomes and food quality/safety. Host resistance is the most effective method of managing plant diseases. Quantitative disease resistance is generally durable and usually works against all variants of pathogens, and thus is an effective disease management tool. This proposal aims to improve the understanding of quantitative disease resistance at multiple levels, from genes to tradeoffs at the whole plant level. The research will focus on some of the most important diseases of corn. The broader impacts of this proposal are twofold. First, the proposed research will identify disease resistance mechanisms in corn, which is both a model species for plant quantitative genetics and the most valuable crop in the US. These results directly relate to ongoing genetic improvement of corn and other important crop species. The second impact is through training of students and postdoctoral scholars during research activities and the education of high school students and teachers during outreach activities. This includes working with a specialist educational organization, The Science House at North Carolina State University. North Carolina State University will participate in and provide funds to continue and update a successful plant breeding and genetics workshop for science teachers that has run annually from 2013 to 2019, as well as participate in a residential Ag-Discovery camp for high school students. In addition, the researchers will engage high school students through the 4-H Illini Summer Academy and Discovering STEM in ACES at the University of Illinois. Quantitative disease resistance (QDR) is the most important form of resistance for maize and crops more broadly. Prior work by this research team and others has shown that QDR is based on diverse genes and mechanisms, most of which are not yet understood. Several quantitative trait loci and genes associated with resistance to multiple maize diseases have been previously identified and characterized. To further dissect disease resistance, as well as other traits, a large population of near-isogenic lines (NILs) has been developed and evaluated for resistance to several diseases. This proposal aims to exploit and develop these data and resources to expand the understanding of QDR and focuses on the following four objectives: 1) develop the NIL population as a resource for the maize genetics community; 2) study QDR, its mechanistic bases, and associated pleiotropies; 3) study the mechanistic bases of vascular disease resistance in maize using microscopy; and 4) identify QDR causal genes using fine mapping and gene editing. This effort will use an integrative approach incorporating genetics, genomics, transcriptomics, histology, pathology/microbiology, quantitative genetics, field research, and CRISPR- mediated gene-editing. Successful completion of this project is expected to result in the identification of key genes, mechanisms and tradeoffs that can inform the deployment of quantitative disease resistance in crops. Since many of the mechanisms under investigation in maize are likely to be broadly applicable, the proposed work will ultimately contribute to a holistic understanding of QDR with a focus on its application to improved crop production and resilience.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.