Mechanisms underlying arsenic tolerance and hyperaccumulation in the fern Pteris vittata

蕨类植物 Pteris vittata 砷耐受和超积累的机制

• 批准号: 0844413
• 负责人: Jo Ann Banks
• 金额: $ 40万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-15 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0844413&HistoricalAwards=false
• 关键词: Mechanisms; underlying; arsenic; tolerance; hyperaccumulation

Arsenic is a naturally occurring, toxic metalloid that is known to cause cancers if consumed. Arsenic contamination of soils and water is an environmental problem in many regions of the world, including the US. This research focuses on the fern Pteris vittata, which is remarkable because it and its close relatives are the only known multicellular organisms that are able to tolerate and accumulate very high levels of arsenic. The goals of this research are to understand how this plant is able to take up and store this toxin without succumbing to its deadly effects. Two genes isolated from this plant are hypothesized to be involved in this process. One is an arsenate reductase, which reduces the arsenate, which is taken up from the soil by the root, to arsenite. The other is an arsenite effluxer that is hypothesized to move arsenite into the vacuole of the cell where it is safely sequestered. One goal of this research is to express these genes in another arsenic-sensitive plant (Arabidopsis thaliana) to see if they are able to confer arsenic tolerance to other plants. A second goal is to localize the proteins produced by these genes at the tissue, cellular and subcellular levels in P. vittata. The final goal is to develop basic genomic tools for P. vittata that ultimately will allow us to identify other genes that are involved in arsenic tolerance and hyperaccumulation in this plant. This research has broader impacts in that it will identify a mechanism of arsenic tolerance and accumulation that may be of practical value in the remediation of arsenic contaminated soils. This research also will provide undergraduate and graduate students, including underrepresented minorities, interdisciplinary training in biochemistry, microscopy, genetics and molecular biology.

砷是一种天然发生的，有毒的金属素，已知会引起癌症。 在包括美国在内的世界许多地区，土壤和水的砷污染是环境问题。 这项研究的重点是蕨类植物vittata，这是非常了不起的，因为它及其近亲是唯一能够耐受和积累高水平的砷的多细胞生物。 这项研究的目标是了解该植物如何能够在不屈服于其致命作用的情况下储存这种毒素。 假设从该植物中分离出的两个基因参与了这一过程。 一种是一种砷酸还原酶，它减少了从土壤中从土壤中占用的砷酸盐，从土壤中占据到砷。 另一种是一种砷排泄剂，假设将砷矿物移入其安全隔离的细胞的液泡中。 这项研究的目标是在另一个砷敏感植物（拟南芥）中表达这些基因，以查看它们是否能够赋予其他植物的砷耐受性。 第二个目标是将这些基因产生的蛋白质定位在维塔塔（P. vittata）的组织，细胞和亚细胞水平。 最终目标是为维塔塔（Vittata）开发基本的基因组工具，最终将使我们能够鉴定出参与该植物中砷耐受性和过度蓄积的其他基因。 这项研究具有更广泛的影响，因为它将确定一种砷耐受性和积累的机制，这对于修复砷污染的土壤可能具有实际价值。 这项研究还将提供本科生和研究生，包括代表性不足的少数民族，生物化学，显微镜，遗传学和分子生物学的跨学科培训。