Functional and Comparative Genomic Analysis of Aluminum Tolerance in Maize

铝（Al）毒性是全球农作物生产的一个严重限制，使多达50%的潜在耕地产量减少。耐铝育种和旨在改善土壤酸度的农艺措施历来是提高作物产量的有效途径。然而，人们普遍认为，额外的耐受性增强将取决于耐铝基因和机制的鉴定，以促进通过生物技术的改进。我们将鉴定和表征玉米耐铝基因及其相关机制，玉米是酸性土壤上生长的最重要的作物之一。我们的研究人群来自不同的来源;因此，我们将捕获广泛的铝耐受水平和有用的等位基因。该项目的核心是耐铝和敏感的近等基因对代表我们已经确定的主要QTL，这些线是基因发现的主要资源。我们的研究目标是：1）确定与特定QTL相关的耐铝生理机制; 2）用选择的近等基因组对分析基因表达谱，以确定与这些QTL相关的候选耐铝基因; 3）通过比较基因组学和遗传关联分析评估和确定候选耐铝基因; 4）存款和管理生成的数据集（遗传连锁，表型，微阵列，核苷酸序列）到公开可用的数据库，包括Gramene，NSF玉米遗传多样性项目，和符合MIAME的表达谱库，用于NSF资助的玉米寡核苷酸项目。建议研究的更广泛影响我们将对一个重要的世界性农业问题进行基础研究。这一问题在南美洲和非洲尤为突出，因为玉米是主要作物，酸性土壤普遍存在。拟议中的研究应大大扩大我们的理解铝耐性的分子和生理基础，产生所需的分子/基因组资源，以提高作物在酸性土壤中的表现。这些信息对传统和生物技术作物改良战略都是有用的。我们将存款从这个项目的信息到公共数据库，这将是有用的基础和应用科学家的广泛收集;核苷酸多态性和表型评分数据收集从远亲玉米品种应该是特别感兴趣的分子进化生物学家和育种家。此外，我们将通过参加由NSF资助的康奈尔大学和博伊斯汤普森研究所设立的以招募少数民族本科生为目标的暑期实习计划（植物基因组研究推广计划），促进代表性不足的群体参与科学。 此外，我们已经建立并将继续运行本科夏季实习生计划与加州州立大学在弗雷斯诺招募西班牙裔本科生到USDA-ARS实验室。

Aluminum (Al) toxicity is a profound limitation to crop production worldwide, reducing yields on up to 50% of potentially arable lands. Breeding for Al tolerance and agronomic practices aimed at ameliorating soil acidity have historically been productive avenues for improved crop production. However, it is widely recognized that additional tolerance enhancement will depend upon the identification of Al tolerance genes and mechanisms to facilitate improvement via biotechnology. We will identify and characterize Al tolerance genes and their associated mechanisms in maize, one of the most important crops grown on acid soils. Our study populations are derived from diverse sources; thus we will capture a wide range of Al tolerance levels and useful alleles. Central to the project are Al tolerant and sensitive NIL pairs representing the major QTLs we already have identified; these lines are a major resource for gene discovery. Our research objectives are: 1) Identify the physiological mechanisms for tolerance associated with specific QTLs; 2) Profile gene expression with selected NIL pairs to identify candidate Al tolerance genes underlying these QTLs; 3) Evaluate and confirm candidate tolerance genes via comparative genomics and genetic association analysis; 4) Deposit and curate the generated datasets (genetic linkage, phenotypes, microarray, nucleotide sequence) into publicly available databases including Gramene, the NSF Maize Genetic Diversity Project, and the MIAME compliant expression profiling repository for the NSF-funded Maize Oligonucleotide Project. Broader Impacts of Proposed ResearchWe will conduct fundamental research on an important worldwide agricultural problem. This problem is especially pronounced in South America and Africa, where maize is a staple crop and acid soils are prevalent. The proposed research should greatly expand our understanding of the molecular and physiological basis of Al tolerance, generating the molecular/genomic resources needed to enhance crop performance in acid soils. This information should be useful for both traditional and biotechnological crop improvement strategies. We will deposit the information from this project into public databases, which will be useful to a broad collection of basic and applied scientists; nucleotide polymorphism and phenotypic scoring data collected from distantly related maize cultivars should be of particular interest to molecular evolutionary biologists and breeders. Furthermore, we will facilitate the participation of under-represented groups in science by participating in the summer internship program that targets recruitment of minority undergraduates that has been established at Cornell University and The Boyce Thompson Institute through funding by NSF (the Plant Genome Research Outreach program). Additionally, we have established and will continue to run an undergraduate summer intern program with California State University at Fresno to recruit Hispanic undergraduate students into USDA-ARS labs.