The Ionome

该项目的目标是使用高通量ICP-MS技术来识别控制各种矿物质的吸收和积累的基因网络，即“离子组”。 靶基因的优先级列表基于四个标准。 首先，所有基因都有未知的功能。 其次，优先考虑主要在根中表达的基因，因为根中的吸收和转运功能对叶和种子离子分布有显著影响。 第三，优先考虑那些对营养素反应表现出表达谱变化的基因。 一个关键的假设是要测试的表达谱的变化是否可以用来确定功能重要的基因。 第四，将优先考虑独特的基因，以检验独特基因的缺陷比基因组中具有密切同源物的基因的突变更可能产生表型的假设。 完整的基因列表可在http://www.cbs.umn.edu/arabidopsis/ionome/上获得。 所有的离子分布数据都可以在网上获得和搜索，各种线路的种子可以通过ABRC获得。 分析离子组及其与其他细胞过程的相互作用对于了解植物如何应对营养供应和有毒金属至关重要。 该合作小组将作为一个“专家中心”，以测试5%的基因组在植物矿物质营养中发挥作用的假设。长期目标是量化拟南芥中每个基因对矿物质营养和离子稳态的功能贡献。 o进行离子分析（铁、锌、钙、钾、锰、磷、硫、硒、钠、铅、砷等的定量）o进行饱和诱变，使用100，000个快中子（FN）诱变的株系来鉴定调节矿物质营养积累的基因。o鉴定从FN诱变获得的50多个离子分布突变体中的突变基因。o对10个离子谱改变的细胞系进行表达谱实验。 我们的目标是关联离子组和转录组分析结果，以了解控制离子homeostasis.Broader影响的网络：有四个关键的贡献，拟议的研究的更广泛的影响。1)教育推广将包括培训本科生和研究生。 2)有关科学对人类健康、农业和生物修复的贡献的信息将通过博物馆展览和与PI当地社区的互动传播。3)研究工具将通过网站和储存中心的种子线储存向公众提供。 4)将提供基础知识，以促进今后提高产量和更有营养的农作物的工程。 对于世界上大多数地区来说，植物是必需矿物质的主要来源。 以食物为基础的“隐性饥饿”解决办法为营养不良问题提供了可持续的解决办法。 因此，该项目将有助于增加植物中的生物可利用矿物质，并解决人类健康的重要问题。 此外，了解有毒金属在植物中积累的途径将使作物工程能够排除有毒金属并创造更健康的食物来源，或从土壤中提取有毒金属作为清理污染土地和水的战略。

The objective of the project is to use high throughput ICP-MS technology to identify gene networks that control uptake and accumulation of a wide array of minerals, the "ionome". The prioritized list of target genes is based on four criteria. First, all genes have unknown functions. Second, priority has been given to genes expressed primarily in roots, as uptake and translocation functions in the root have a significant influence on leaf and seed ion profiles. Third, priority is given to those genes that show expression profile changes in response to nutrients. A critical hypothesis to be tested is whether expression profiling changes can be used to identify functionally important genes. Fourth, priority will be given to unique genes to test the hypothesis that defects in unique genes are more likely to generate a phenotype than mutations in genes with close homologs in the genome. A complete gene list is available at http://www.cbs.umn.edu/arabidopsis/ionome/. All the ion profiling data will be available and searchable online, with seeds for various lines available through the ABRC. Analysis of the ionome and its interactions with other cellular processes is essential to understand how plants respond to nutrient availability and toxic metals. The collaborative group will serve as a "Center of Expertise" to test the hypothesis that 5% of the genome functions in plant mineral nutrition. The long-term goal is to quantify the functional contribution to mineral nutrition and ion homeostasis of every gene in Arabidopsis. The main objectives are to:o Conduct ion profiling (quantitation of Fe, Zn, Ca, K, Mn, P, S, Se, Na, Pb, As, etc.) in leaves and seeds of 1600 homozygous disruption lines isolated in genes of unknown function, and thousands of additional lines made available by the Arabidopsis community.o Conduct saturation mutagenesis, using 100,000 fast neutron (FN) mutagenized lines to identify genes that regulate mineral nutrient accumulation. o Identify the mutant genes in more than 50 ion profile mutants obtained from FN mutagenesis. o Conduct expression profiling experiments on 10 lines with altered ion profiles. The goal is to correlate ionome and transcriptome profiling results to understand the networks controlling ion homeostasis.Broader Impacts: There are four key contributions to the Broader Impacts of the proposed research. 1) Educational outreach will include training of undergraduate and graduate students. 2) Information on the contribution of science to human health, agriculture, and bioremediation will be disseminated through museum exhibits and interactions with the PIs' local communities. 3) Research tools will be provided to the public through web sites and seed line deposits at stock centers. 4) Fundamental knowledge will be provided to facilitate future engineering of increased yields and of more nutritious agricultural crops. For most of the world, plants are the major source of essential minerals. Food-based solutions to "hidden hunger" offer sustainable solutions to problems of malnutrition. Therefore, this project will contribute to increasing bio-available minerals in plants and to solving important problems in human health. Furthermore, understanding the pathways by which toxic metals accumulate in plants will enable the engineering of crops to exclude toxic metals and create healthier food sources, or to extract toxic metals from the soil as a strategy to clean up polluted lands and water.