Project 7: Molecular Mechanisms of Heavy Metal Detoxification and Accumulation

项目7：重金属解毒和积累的分子机制

基本信息

批准号：
9043082
负责人：
JULIAN I SCHROEDER
金额：
$ 25.32万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9043082
关键词：
Arabidopsis Arsenic Arsenites Biochemical Biological Biological Availability Bioremediations Burial Cadmium Cell membrane Complex Decontamination Detection Drug Metabolic Detoxication Engineering Environmental Health Environmental Pollution Excision Future Gene Expression Genes Genetic Genomics Glutathione Goals Hazardous Substances Health Heavy Metals Homologous Gene Human Hybrids Instruction Knock-out Lead Libraries Luciferases Mediating Membrane Transport Proteins Mercury Metals Modeling Molecular Molecular Genetics Pathway interactions Peptides Physiological Plant Leaves Plant Roots Plant Shoots Plants Play Regulation Reporter Reporting Repression Research Research Support Resistance Site Soil Source Sulfhydryl Compounds Superfund System Technology Testing Toxicant exposure Transcription Repressor/Corepressor Vacuole Water Work Yeasts base cost effective gene function genome-wide high throughput screening human disease insight malignant neurologic neoplasms metal complex mutant nervous system disorder novel phytochelatin plant fungi remediation response screening superfund site tool toxic metal transcription factor uptake

项目摘要

PROJECT SUMMARY (See instructions): Soils and waters with high levels of toxic heavy metal(loid)s such as arsenic, cadmium and mercury are detrimental to human and environmental health. These three metal(loid)s are among the Superfund's top 7 priority hazardous substances. 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 important genes and pathways that function in heavy metal over-accumulation in plants remain to be identified. In recent research we have made major advances at understanding key mechanisms that function in heavy metal detoxification, transport and accumulation in plants. We will combine powerful genomic, genetic, biochemical and physiological approaches to test new central hypotheses by pursuing the following Specific Aims: I Characterize newly identified vacuolar membrane transporters that function in uptake and accumulation of phytochelatin-heavy metal(loid) complexes into plant vacuoles and analyze their bioremediation potential. Il Understanding the control of heavy metal accumulation and distribution in roots and shoots is critical for engineering of plants for bioremediation. Determine the mechanisms by which a new peptide transporter mutant, opt3, causes hyper-accumulation in roots and under-accumulation of cadmium in plant leaves. IIl Our recent research has shown that heavy metal-chelating and detoxifying thiols undergo long distance transport in plants. However, the plasma membrane transporters for uptake of glutathione (GSH) and phytochelatins (PCs) remain unknown. Using a high-throughput screen we have now identified OPT4 as a putative GSH & PC-Cd transporter. We will characterize 0PT4 and additional transporters to determine their underlying GSH/PC-Cd/As transport mechanisms and their functions in heavy metal distribution in plants. IV. The mechanisms and transcription factors that mediate rapid heavy metal-induced gene expression in plants remain largely unknown, but are important for heavy metal resistance and accumulation. The genes of newly isolated mutants impaired in cadmium-induced gene expression will be identified and their functions characterized. Furthermore, a potent genome-wide approach has been developed and will be pursued to identify and characterize key transcription factors and repressors that control cadmium- and arsenic-induced gene expression. We will work closely with the RTC and CEC in sharing our advances and foremost in translational analyses of our findings for their potential in phytoremediation of contaminated soils and waters.

项目摘要（参见说明）：砷、镉和汞等有毒重金属含量高的土壤和水体对人类和环境健康有害。这三种金属（类金属）属于超级基金的七大优先危险物质之一。研究和应用表明，植物通过根系吸收重金属以及植物芽中重金属的积累可以为有毒金属去除和富含重金属的土壤和水体的修复提供一种经济有效的方法。然而，在植物重金属过度积累中起作用的重要基因和途径仍有待确定。在最近的研究中，我们在了解植物重金属解毒、运输和积累的关键机制方面取得了重大进展。我们将结合强大的基因组、遗传、生化和生理学方法，通过追求以下具体目标来测试新的中心假设：我表征了新发现的液泡膜转运蛋白，其在植物液泡中吸收和积累植物螯合素-重金属（类）复合物方面发挥作用，并分析了它们的生物修复潜力。 Il 了解根和芽中重金属积累和分布的控制对于生物修复植物工程至关重要。确定新的肽转运蛋白突变体 opt3 导致根部过度积累和植物叶子中镉积累不足的机制。我们最近的研究表明，重金属螯合和解毒硫醇在植物中进行长距离运输。然而，摄取谷胱甘肽（GSH）和植物螯合素（PC）的质膜转运蛋白仍然未知。使用高通量筛选，我们现在已将 OPT4 鉴定为推定的 GSH 和 PC-Cd 转运蛋白。我们将表征 0PT4 和其他转运蛋白，以确定其潜在的 GSH/PC-Cd/As 转运机制及其在植物中重金属分布中的功能。四．介导植物中重金属诱导的基因快速表达的机制和转录因子在很大程度上仍然未知，但对于重金属抗性和积累很重要。新分离的镉诱导基因表达受损的突变体的基因将被鉴定并表征其功能。此外，已经开发出一种有效的全基因组方法，并将用于识别和表征控制镉和砷诱导的基因表达的关键转录因子和阻遏物。我们将与 RTC 和 CEC 密切合作，分享我们的进展，最重要的是对我们的发现进行转化分析，以了解其在污染土壤和水体植物修复方面的潜力。