Project 9: Arsenic Uptake, Transport and Accumulation in Plants

本项目旨在研究植物体内砷(As)动态平衡的遗传控制。这将使 能选择性地从组织中排除砷，防止砷在食物中积累的植物的发育 农作物和减少人类饮食中砷的摄入量。砷是S关注的主要金属(固体)之一 超级基金地点和长期低剂量暴露与膀胱癌发病率增加有关。 人体摄入砷的饮食研究表明，在饮用水后，白米是最重要的 无机物的来源，如人类的。一项市场篮子调查发现，随着美国市场集中度的提高，市场集中度更高 在孟加拉三角洲受AS影响的地区种植的水稻比种植的大米要少。在美国大米中，人们认为 来自棉花生产中使用的砷杀虫剂，但作为对土壤的投入来自于各种 工业消息来源。我们的目标是以拟南芥、水稻和超积累的制动蕨类为模式植物。 系统。它们代表了两个拥有完整基因组序列的物种；最重要的主食之一 粮食作物植物和无机盐的重要膳食来源对人类来说，也是为数不多的植物之一 具有内在AS抗性的物种。我们建议使用一种跨学科的方法，结合离子学 调查技术、数量性状基因座(QTL)定位和空间分辨金属(Loid)分析 通过同步加速器X射线微探头(SXRM)进行物种形成。研究战略包括基因发现和 基因表征阶段。对于基因发现，方法包括挖掘现有的数据集 4,000份酵母菌和62,000份拟南芥样品的元素图谱 此外，还研究了阿拉伯薯属天然种质在砷积累方面的差异。我们将使用高吞吐量 元素分析和基于DMA微阵列的定位以识别调节AS的基因 在水稻中积累，筛选1790份美国农业部水稻核心种质 柠檬X特青作图群体中As的QTL我们将使用SXRM来调查 缺失导致的微米级金属(Loid)在植物组织中的分布、丰度和/或形态 或沉默选定的感兴趣的基因。这项技术成功地表征了基因 在最近的一项铁稳态研究中发挥的作用。基因表征阶段的一个重要产品将是 是向更广泛的科学工作者提供的拟南芥属元素地图集的在线出版物 这项拟议的研究将X射线技术的应用扩展到空间分辨的 将分析技术转变为对离子稳态基因进行功能表征以及保护的工具 人类的食物供应。

This project aims to study the genetic control of arsenic (As) homeostasis in plants. This will enable the development of plants that can selectively exclude As from their tissues, preventing As accumulation in food crops and reducing human dietary intake of As. Arsenic is one of the primary metal(loid)s of concern at Superfund Sites and chronic low-dose exposure is linked to an increased incidence of bladder cancer. Dietary studies of As intake in humans show that after drinking water, white rice is the most significant source of inorganic As for humans. A market basket survey found higher As concentrations in U.S. grown rice than rice grown in the As-affected regions of the Bengal Delta. In U.S. rice, As is thought to have come from arsenical pesticides used in the production of cotton, but As input to soil comes from a variety of industrial sources. We aim to use Arabidopsis, rice and the As-hyperaccumulating brake fern as model plant systems. They represent two species with a completed genomic sequence; one of the most important staple food crops plants and an important dietary source of inorganic As for humans, and one of the few plant species with intrinsic As resistance. We propose to use an interdisciplinary approach that combines ionomic survey techniques, quantitative trait loci (QTL) mapping and spatially resolved metal(loid) analysis and speciation via synchrotron x-ray microprobe (SXRM). The research strategy consists of gene discovery and gene characterization phases. For gene discovery, approaches include mining an existing dataset of elemental profiles of 4,000 yeast and 62,000 Arabidopsis samples for those with altered As phenotypes as well as examining natural accessions of Arabdiospis for differences in As accumulation. We will use highthroughput elemental analysis and DMA microarray-based mapping to identify genes that regulate As accumulation in rice, screening 1,790 rice accessions with the USDA's Rice Core Collection and examining QTLs for As in the Lemont X Teqing mapping population. We will use SXRM to investigate changes in the micron-scale metal(loid) distribution, abundance and/or speciation in plant tissue resulting from the deletion or silencing of selected genes of interest. This technique allowed successful characterization of gene function in a recent study of iron homeostasis. An important product of the gene characterization phase will be the online publication of an Elemental Atlas of Arabidopsis available to the wider scientific community.This proposed research expands the application of x-ray techniques beyond a spatially-resolved analytical technique into a tool for functionally characterizing ion homeostasis genes, as well as protecting human food supplies.