Arsenic Uptake, Transport and Storage in Plants

项目1：摘要 大米是世界上一半以上人口的主食，代表着重要的饮食来源 无机砷(As)，一种非临界值的1类人类致癌物。当务之急是制定减少 粮食AS被开发，并建立使As能够到达并在 米粒是这一努力的关键。该项目将阐明AS在植物体内的动态平衡的遗传控制 使那些不积累为的植物得以生长。第一个明确的目标是检验这样一个假设 水稻的遗传多样性可以通过定位已知水稻品种的基因来降低籽粒砷水平。 谷物含量不同。第二个目的更笼统地问，什么基因参与了转移 谷物和第三个目标测试基于信息限制AS向地上部/谷粒移动的策略 从水稻、拟南芥和积累砷的蕨类植物凤尾草的研究中获得。长期目标是 防止砷在稻谷的可食用部分积累，但这项工作也可能提供信息 砷等污染金属(Loid)向其他食用菌组织转运的基因研究 植物器官。除了确定病因外，同步加速器X射线荧光微量分析(SXRF) 将被用来像在植物中一样精确地进行本地化和种化，这是一种已经使用的创新方法 成功地检测了As的种子载量。

Project 1: Abstract Rice (Oryza sativa), a staple food for over half the world's population, represents a significant dietary source of inorganic arsenic (As), a non-threshold, class 1 human carcinogen. It is imperative that strategies to reduce grain As are developed, and establishing the mechanisms that enable As to reach and accumulate within the rice grain is key to this endeavor. This project will elucidate the genetic control of As homeostasis in plants to enable the development of plants that do not accumulate As. The first specific aim tests the hypothesis that genetic diversity in rice can be exploited to lower grain As levels by mapping genes in accessions known to vary in grain As content. The second aim asks more generally what genes are involved in transferring As to the grain and the third aim tests strategies to limit the movement of As to the shoot/grain based on information gained from study of rice, Arabidopsis and the As accumulating fern Pteris vittata. The long-term goal is to prevent As accumulation in the edible portion of rice grain, but the work will also potentially provide information on genes responsible for transporting As and other contaminant metal(loid)s into the tissues of other edible plant organs. In addition to identifying the causal loci, synchrotron X-ray fluorescence microanalysis (SXRF) will be used to precisely localize and speciate As in plants, an innovative approach that has been used successfully to examine seed loading of As.