RESEARCH-PGR: A Genome-level Approach to Balancing the Vitamin Content of Maize Grain

研究-PGR：平衡玉米籽粒维生素含量的基因组水平方法

• 批准号: 1546657
• 负责人: Dean DellaPenna
• 金额: $ 441.19万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1546657&HistoricalAwards=false
• 关键词: RESEARCH; PGR; Genome; level; Approach

This collaborative research project is directed at identifying a subset of the ~40,000 genes in the corn genome that work together to determine the levels of five essential and limiting dietary vitamins in kernels: vitamin E and the four B vitamins, B1 (thiamin), B2 (riboflavin), B3 (niacin) and B6 (pyridoxine). By combining approaches similar to those used in the Human Genome project, the researchers will identify alleles, special variations in these "vitamin" genes, and learn how to put them together to generate high amounts of vitamins in corn kernels. An important outcome of this research will be the knowledge by which to enhance these micronutrient levels in corn kernels such that diets in which maize is a major component provide a balanced nutritional content. Such direct translation of these findings will be the eventual incorporation and fixation of identified alleles in maize breeding programs that are favorable for the increased levels of vitamins E and B to enhance the food and feed supply chain. In addition, this research will provide guiding principles for parallel efforts in other agricultural crops and thus enable predictive breeding and metabolic engineering of more nutritious crops worldwide. Finally, integration of research with education within the project will permit training of the next generation of plant scientists with knowledge of plant genetics, breeding, genomics, biochemistry, and bioinformatics. This project seeks to leverage the tremendous genetic and genomic tool sets developed in maize the past decade to advance and accelerate our fundamental understanding of the genes, alleles and genetic mechanisms controlling synthesis and accumulation of vitamins that are limiting in maize grain and hence result in vitamin deficiencies in maize-based diets: four B vitamins (B1, thiamine; B2, riboflavin; B3, niacin; B6, pyridoxine) and vitamin E. This project brings together a team of scientists with divergent but complementary knowledge and skills that together will allow the genes, alleles and underlying mechanisms controlling these nutritional traits to be elucidated and the knowledge deployed on a global scale. Specific objectives are to (i) perform genome-wide association studies with the maize Ames inbred line panel (n~2,000) to identify and resolve quantitative trait loci (QTL) controlling accumulation of these micronutrients; (ii) assess the role of rare alleles by constructing and analyzing segregating F2 populations derived from Ames lines that are extreme outliers for traits; (iii) determine the contribution of expression QTL and presence-absence variants (PAVs) to vitamin composition using whole transcriptome sequencing data obtained from grain 24 days after pollination in 500 inbred lines that represents the phenotypic variation of the Ames panel; and, (iv) perform genomic prediction with the Ames panel to accelerate the efficiency of breeding improved grain micronutrient composition in developing countries. The broader impacts of this project to the broader scientific community and public will be ensured through a set of coordinated activities that engage students, postdoctoral associates, scientists and the public. Data and biological resources generated in this project will be made accessible to the community. Data will be disseminated through publications, project websites and long-term repositories such as the NCBI's SRA and MaizeGDB.

这项合作研究项目旨在确定玉米基因组中约40，000个基因的一个子集，这些基因共同确定玉米粒中五种必需和限制性膳食维生素的水平：维生素E和四种B族维生素，B1（硫胺素），B2（核黄素），B3（烟酸）和B6（吡哆醇）。通过结合类似于人类基因组项目中使用的方法，研究人员将识别等位基因，这些“维生素”基因的特殊变异，并学习如何将它们放在一起，以在玉米粒中产生大量的维生素。 这项研究的一个重要成果将是提高玉米粒中这些微量营养素水平的知识，以便以玉米为主要成分的饮食提供均衡的营养成分。这些发现的这种直接转化将是在玉米育种计划中最终掺入和固定鉴定的等位基因，这有利于增加维生素E和B的水平，以增强食品和饲料供应链。此外，这项研究将为其他农作物的平行工作提供指导原则，从而使全球更有营养的作物的预测育种和代谢工程成为可能。 最后，该项目内的研究与教育相结合，将允许培养下一代植物科学家，掌握植物遗传学、育种、基因组学、生物化学和生物信息学的知识。该项目旨在利用过去十年在玉米中开发的巨大遗传和基因组工具集，以推进和加速我们对控制玉米籽粒中限制维生素合成和积累的基因、等位基因和遗传机制的基本理解，从而导致玉米饮食中的维生素缺乏：四种B族维生素（B1，硫胺素; B2，核黄素; B3，烟酸; B6，吡哆醇）和维生素E。该项目汇集了一组具有不同但互补的知识和技能的科学家，这些科学家将共同阐明控制这些营养性状的基因，等位基因和潜在机制，并在全球范围内部署知识。具体目标是（i）对玉米艾姆斯近交系组（n~ 2，000）进行全基因组关联研究，以鉴定和解析控制这些微量营养素积累的数量性状基因座（QTL）;（ii）通过构建和分析来自性状极端离群值的艾姆斯系的分离F2群体来评估稀有等位基因的作用;（iii）使用从500个代表艾姆斯小组表型变异的近交系中授粉后24天的谷粒获得的全转录组测序数据，确定表达QTL和存在-不存在变体（PAV）对维生素组成的贡献;以及（iv）与艾姆斯小组一起进行基因组预测，以加快发展中国家培育改良谷物微量营养素组成的效率。将通过一系列协调一致的活动确保该项目对更广泛的科学界和公众产生更广泛的影响，这些活动将吸引学生、博士后、科学家和公众的参与。该项目产生的数据和生物资源将向社区开放。数据将通过出版物、项目网站和NCBI的SRA和MaizeGDB等长期储存库传播。