Molecular Mechanisms of Heavy Metal Detoxification

重金属解毒的分子机制

• 批准号: 6897647
• 负责人: JULIAN I SCHROEDER
• 金额: $ 21.62万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6897647
• 关键词: Arabidopsis; Cruciferae; bioaccumulation; biological signal transduction; biological transport; cadmium; detoxification; field study; genetically modified plants; hazardous substances; heavy metals; high throughput technology; leaf; metal poisoning; microarray technology; molecular cloning; plants; root; soil pollution; toxicant screening

DESCRIPTION (provided by applicant): Soils and waters with high levels of toxic heavy metals such as cadmium, arsenic, lead and mercury are detrimental to human and environmental health. These 4 metal(loid)s are among the Superfund's top 7 priority hazardous substances. Recent research and applications indicate that uptake of heavy metals into plants via the root system and accumulation of heavy metals in plant shoots could provide a cost effective approach for toxic metal removal and remediation of heavy metal-laden soils and waters. However many genes, mechanisms and pathways that function in heavy metal over-accumulation in plants remain to be identified and characterized. Phytochelatins are major heavy metal and metalloid chelating and detoxifying thiolate peptides in plants. In recent research we have made advances at understanding mechanisms that contribute to heavy metal detoxification and transport in plants, including isolation of phytochelatin synthase genes, characterization of mechanisms for root to shoot transfer of cadmium, isolation of heavy metal accumulation Arabidopsis mutants, development of a novel microarray-based rapid mutant cloning approach and microarray-based identification of putative transporter genes that may contribute to heavy metal transport. The investigators will test the hypotheses that, phytochelatins affect long distance root to leaf vascular transport of toxic metals; characterization of new toxic metal accumulation mutants will lead to identification of rate-limiting steps that function in plant heavy metal accumulation; and heavy metal sensing and signal transduction mechanisms in plants are important for plant heavy metal resistance and accumulation. To test these hypotheses, the proposed project will, in Specific Aims 1 and 2, characterize novel physiological and molecular mechanisms of root to shoot transport of heavy metals and phytochelatins using physiological, genomic, biochemical and membrane transport analyses. By pursuing a new high-throughput screening approach in collaborative research, the investigators have identified Arabidopsis mutants that affect the accumulation of toxic metals in leaves. In Specific Aim 3, a newly developed genomic microarray-based rapid mutant mapping and cloning approach will be used to isolate selected heavy metal accumulation mutant genes and characterize the underlying mechanisms. Specific Aim 4 will be to characterize heavy metal biosensing and transduction mechanisms in plants using a luciferase reporter screen. Trials with contaminated soils from Superfund sites will be pursued in collaboration with Edenspace Corp (in Specific Aim 5), to assess the feasibility of monitoring bioavailable heavy metals and of hyperaccumulating heavy metals and metalloids into plant roots and shoots using transgenic and mutant plants generated in this research.

描述（由申请人提供）：镉，砷，铅和汞等有毒重金属的土壤和水对人类和环境健康有害。这4个金属（Lie）S是超级基金的前7个优先级危险物质。 最近的研究和应用表明，通过根系，将重金属吸入植物，而重金属在植物芽中的积累可以为有效的金属去除和对重金属土壤和水的修复提供一种经济有效的方法。 然而，在重金属过度积累植物中起作用的许多基因，机制和途径仍有待鉴定和表征。 植物chelatins是主要的重金属和金属螯合，并在植物中排毒硫醇肽。 In recent research we have made advances at understanding mechanisms that contribute to heavy metal detoxification and transport in plants, including isolation of phytochelatin synthase genes, characterization of mechanisms for root to shoot transfer of cadmium, isolation of heavy metal accumulation Arabidopsis mutants, development of a novel microarray-based rapid mutant cloning approach and microarray-based identification of putative transporter genes that may contribute to heavy metal transport. 研究人员将测试植物毒素影响有毒金属叶血管转运的长距离根部的假设。新有毒金属积累的表征 突变体将导致识别限速步骤，这些步骤在植物重金属积累中起作用；植物中的重金属感应和信号转导机制对于植物重金属耐药性和积累至关重要。 为了检验这些假设，在特定的目标1和2中，拟议的项目将使用生理，基因组，生化和膜转运分析来射击重金属和植物毒素的新型生理和分子机制。 通过在协作研究中采用新的高通量筛选方法，研究人员确定了影响叶子中有毒金属积累的拟南芥突变体。在特定的目标3中，新开发的基于基因组微阵列的快速突变映射和克隆方法将用于隔离选定的重金属积累突变基因并表征基本机制。特定目标4将是表征重金属生物传感和转导 使用荧光素酶报告器屏幕的植物机制。 将与Edenspace Corp（在特定目标5中）合作进行与超级基金站点受污染的土壤的试验，以评估监测生物可用性重金属的可行性，并使用该研究中生成的转基因和突变植物，并将重金属和金属固醇过度累积到植物的根和植物中。