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Effects of nanomolar heavy metal concentrations on plants - comparison of biochemical&biophysical mechanisms of deficiency and sublethal toxicity under environmentally relevant conditions

纳摩尔重金属浓度对植物的影响——生化比较

基本信息

批准号：
169833033
负责人：
Professor Dr. Hendrik Küpper
金额：
--
依托单位：
Deutsches Elektronen-Synchrotron (DESY)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/169833033?language=en
关键词：
Effects nanomolar heavy metal concentrations

项目摘要

In this project we are investigating mechanisms of heavy metal toxicity and deficiency. We started this in the water plant Ceratophyllum demersum as a model for shoots, and now also transfer the knowledge obtained from this model to crop plants. While many potential mechanisms of metal toxicity induced damage have been proposed, most of them were investigated only under rather artificial laboratory conditions. Therefore, we are evaluating the relevance of different proposed mechanisms of metal-induced inhibition under environmentally relevant conditions and are comparing these results with those obtained under conditions that were used in identifying the putative toxicity mechanisms. We have chosen copper, chromium and cadmium as model heavy metals, plus arsenic as a toxic metalloid, because they most frequently reach toxic concentrations in contaminated environments. We apply environmentally relevant conditions in terms of concentrations, biomass/water volume ratios, light and temperature cycles and incubation times. In the past 39 months of the project, the focus was at the beginning on the analysis of the toxicity of lake Ammelshain samples and the determination of reasons for their toxicity by systematic re-constitution of field conditions in the laboratory. Afterwards we systematically investigated mechanisms of deficiency of copper and chromium, as well as toxicity of arsenic, cadmium and copper. The deficiency & toxicity analysis was started with in vivo measurements of photosynthesis biophysics, formation of reactive oxygen species and oxygen exchange, combined with pigment, starch and metal analyses, and is currently being continued by analysis of cellular and subcellular metal distribution and speciation, as well as metalloproteomics. In the coming years, we want to transfer the knowledge obtained with the model plant to crop species (mainly soybean and barley), with special emphasis on cellular and subcellular metal distribution (via µXRF) and speciation (via µXANES), as well as metalloproteomics and metabolomics. Thus we want to investigate further how in plants metal deficiency and onset of metal toxicity lead to a change in metal distribution between different tissues, different cellular compartments and different metal-binding proteins, rather than a general concentration change in many tissues. Further, we want to clone the genes of novel metal-binding proteins to further characterise them and reveal their function by modifying their expression in the crop species and Arabidopsis thaliana. This particularly applies the proteins that bind Cr under optimal and Cr-deficient conditions, where we already have a preliminary identification of one of these proteins.

在本项目中，我们对重金属毒性和缺乏的机制进行了研究。我们首先在水生植物金鱼藻中建立了一个枝条模型，现在也将从这个模型中获得的知识转移到农作物中。虽然已经提出了许多潜在的金属毒性损伤机制，但大多数都是在相当人工的实验室条件下进行研究的。因此，我们正在评估不同建议的金属诱导抑制机制在环境相关条件下的相关性，并将这些结果与用于确定假定毒性机制的条件下的结果进行比较。我们选择铜、铬和镉作为模型重金属，再加上砷作为有毒的类金属，因为它们在受污染的环境中最常达到有毒浓度。我们在浓度、生物量/水体积比、光和温度循环以及孵化时间方面应用与环境相关的条件。在过去39个月的项目中，重点是开始分析Ammelshain湖样品的毒性，并通过实验室系统地重建现场条件来确定其毒性的原因。随后，我们系统地研究了铜、铬缺乏的机制，以及砷、镉、铜的毒性。缺陷和毒性分析始于体内光合作用生物物理、活性氧物种的形成和氧交换的测量，结合色素、淀粉和金属分析，目前正在继续进行细胞和亚细胞金属分布和形态的分析，以及金属蛋白质组学。在未来几年，我们希望将从模式植物获得的知识转移到作物物种(主要是大豆和大麦)，特别重视细胞和亚细胞金属分布(通过µXRF)和物种形成(通过µXANES)，以及金属蛋白质组学和代谢组学。因此，我们想要进一步研究在植物中，金属缺乏和金属毒害是如何导致金属在不同组织、不同细胞隔间和不同金属结合蛋白之间分布的变化，而不是在许多组织中普遍的浓度变化。此外，我们想要克隆新的金属结合蛋白的基因，以进一步表征它们，并通过改变它们在农作物和拟南芥中的表达来揭示它们的功能。这尤其适用于在最佳和缺铬条件下与铬结合的蛋白质，我们已经初步鉴定了其中一种蛋白质。