Physiological Genomics of Maize Nodal Root Growth under Drought

PI：Robert E.夏普（密苏里州大学）CoPIs：大卫M。Braun，Felix B.放大图片作者：Scott C.作者：Jonathan T. Stemmle（密苏里州大学）和Melvin J.奥利弗（USDA-ARS/密苏里州大学）开发能够有效利用可用水的耐旱玉米品种对于到2050年维持估计90亿全球人口至关重要。玉米通过一组特殊的根（称为节根）吸收大部分水分。在干旱的情况下，节状的根必须穿过干燥的土壤生长，以获得可用的水分来维持植物。然而，很少有人知道的机制，让节根实现这一重要壮举。该项目将使用生理学和基因组学方法的组合来定义节根如何能够在干旱下保持生长的分子机制。该项目产生的信息将导致制定创新办法，使玉米和其他谷类作物能够在干旱情况下获得更多的水和增加产量，从而有助于实现加强粮食安全和稳定的基本目标。除了对学生和博士后进行培训外，该项目还将为来自福特瓦利州立大学的本科生提供暑期研究培训实习机会，这是一所位于福特瓦利（佐治亚州）的历史上的黑人大学（HBCU）。该项目还将通过各种交流、技术培训和外联活动，传播研究成果并向公众提供信息。这些包括但不限于涉及新闻专业学生的科学传播研讨会和关于代谢组学的实践培训研讨会，以及使用生物信息学工具分析和整合多组学数据集。 该项目整合了根生理学和功能基因组学[转录组学，质膜蛋白质组学和代谢组学（包括激素）]，以全面了解节根生长对水分亏缺胁迫的反应，无论是在受控的实验室研究还是在田间。该项目的重点是一个玉米自交系，已被证明表现出上级能力的节根生长在水分有限的条件下。一个跨学科的合作小组将致力于以下具体目标：1）阐明节根生长响应水分胁迫的生理和分子基础，使用一种新的分室模型系统，精确施加水分亏缺条件周围的生长根; 2）表征响应于田间水分胁迫的节根生长和根生长区转录组学响应，使用“干旱模拟器”精确设定干旱的时间、强度和持续时间; 3）使用一套信息学工具整合和分析所有数据集，以确定将在植物中进行基因验证的候选基因。这一多学科战略提供了独特的机会，大大提高了对干旱下根系生物学的基本认识，并广泛培训下一代植物科学家。该项目产生的数据和生物材料将可在项目网站（待开发）上查阅，并可存入长期储存库，如玉米遗传学合作社（种质）、玉米遗传数据库、Gramene和NCBI的GEO和SRA（序列和表型数据集）。

PI: Robert E. Sharp (University of Missouri)CoPIs: David M. Braun, Felix B. Fritschi, Trupti Joshi, Scott C. Peck, Jonathan T. Stemmle (University of Missouri) and Melvin J. Oliver (USDA-ARS/University of Missouri) Developing drought-tolerant corn varieties that make efficient use of available water is vital to sustain the estimated 9 billion global population by 2050. Corn takes up most of its water through a particular set of roots called the nodal roots. Under drought, the nodal roots must grow through dry soil to reach available water to sustain the plant. However, very little is known about the mechanisms that allow nodal roots to achieve this essential feat. This project will use a combination of physiological and genomics approaches to define the molecular mechanisms underlying how the nodal roots are able to maintain growth under drought. The information generated by the project will lead to the development of innovative approaches to enable corn and other cereal crops to access more water and increase yield under drought, and will thereby contribute to the essential goals of increased food security and stability. In addition to the training of students and postdoctoral associates, the project will provide summer research training internships for undergraduate students from Fort Valley State University, a Historically Black University (HBCU) located in Fort Valley (GA). The project will also disseminate research findings and provide information to the general public through various communication, technical training and outreach activities. These include but are not limited to science communication workshops involving journalism students and hands-on training workshops on metabolomics and the use of bioinformatics tools to analyze and integrate multi-omics datasets. This project integrates root physiology and functional genomics [transcriptomics, plasma membrane proteomics, and metabolomics (including hormones)] to deliver a comprehensive understanding of nodal root growth responses to water deficit stress in both controlled laboratory studies and in the field. The project focuses on a maize inbred line that has been shown to exhibit superior ability for nodal root growth under water-limited conditions. A collaborative interdisciplinary team will address the following specific objectives: 1) elucidation of the physiological and molecular basis of nodal root growth responses to water stress using a novel divided-chamber model system for precise imposition of water deficit conditions around the growing roots; 2) characterization of nodal root growth and root growth zone transcriptomic responses in response to water stress in the field, using "drought simulators" for precise imposition of the timing, intensity and duration of drought; and 3) integration and analysis of all datasets using a suite of informatics tools to identify candidate genes that will be genetically validated in plants. This multidisciplinary strategy provides unique opportunities to greatly improve basic understanding of root biology under drought, and to broadly train the next generation of plant scientists. Data and biological materials generated by this project will be accessible to a project website (to be developed) and through deposition to long-term repositories such as the Maize Genetics Cooperative (for germplasm), and MaizeGDB, Gramene and the NCBI's GEO and SRA (for sequence and phenotypic datasets).