Ecophysiology and genetic analysis of plant adaptation to soil metal contamination

土壤中金属浓度过高对植物生态系统的可持续性构成严重威胁。对长期接触高水平金属对生理和遗传机制的影响缺乏了解。在过去的15年里，我们确定了对金属污染地区树木大小分布、功能、适应和恢复过程至关重要的土壤因素；我们评估了生长在金属污染地区的碎片化植物种群的等位基因变化和遗传变异性；我们已经建立了金属污染与丛生德香槟细胞学破坏之间的明确联系。植物对镍和铜的耐受性的遗传机制尚不清楚，镍和铜是加拿大几个矿区发现的主要污染物。近年来，我们发现丛生毛草和阔叶树种[(杨树)、红栎树、红枫枫]对铜、镍的耐性机制不同。这项拟议的研究的主要目标是了解与细胞中金属积累相关的金属和蛋白质的细胞隔间位置。这最终可以使我们找到与金龟子和金龟子中金属耐受性有关的基因。我们的研究将结合电子显微镜、荧光原位、细胞培养和蛋白质表征技术来确定细胞和细胞外金属的位置和影响以及涉及的运输蛋白。通过QTL定位和连锁分析，将利用一组独特的耐铜、耐镍的杂交种，确定与丛毛石竹耐铜、耐镍相关的基因。将在“组学”水平上对来自金属污染和未污染场地的微囊藻进行详细分析，以了解与铜和镍耐受性相关的代谢功能。使用微阵列的比较分析将允许识别在对过量的铜和镍的反应中受到不同调控的功能基因集。更重要的是，一名博士后，两名博士和两名硕士。预计学生将在研究计划的这一阶段接受培训，以填补加拿大生物技术和生物修复方面的空白。

Excessive concentrations of metals in soil represent serious threats to plant ecosystem sustainability. Knowledge of the effects of long term exposure to high levels of metals on physiological and genetic mechanisms is lacking. In the last 15 years, we have determined soil factors important to tree size distribution, function, adaptation and restoration process in metal contaminated regions; we have assessed the allelic changes and genetic variability of fragmented plant populations growing in metal areas; and we have established a clear linkage between metal contamination and cytological disruption in Deschampsia cespitosa. The genetic mechanisms of plant tolerant to nickel and copper, the main pollutants found in several mining areas in Canada are not well understood. Recently, we have established that the main physiological mechanism involved in D. cespitosa (tufted hair grass) and hardwood species [(Populus tremuloides (poplar), Quercus rubra (red oak), and Acer rubrum (red maple)] tolerance to Cu and Ni are different. The main objectives of this proposed research is to know cell compartment locations of metal and proteins associated with metal accumulation in cells. This can eventually lead us to identifying genes involved in metal tolerance in D. cespitosa and P. tremuloides. Our study will combine electron microscopy, fluorescence in situ, cell culture, and protein characterization techniques to determine cellular and extracellular location et effects of metals along with the transport proteins involved. Genes associated with Cu and Ni tolerance in D. cespitosa will be determined by QTL mapping and linkage analysis using a unique set of Cu and Ni tolerant progenies developed in a D. cespitosa breeding program. Detailed analysis of D. cespitosa from metal contaminated and uncontaminated sites at “omics” levels will be performed to understand metabolic functions associated with Cu and Ni tolerance. Comparative analysis using microarrays will allow the identification of functional gene sets that are differentially regulated during the response to excess Cu and Ni. More importantly, one post-Doctoral fellow, two Ph.D. and two M.Sc. students are expected to be trained during this phase of the research program to fill the void in biotechnology and bioremediation in Canada