Plant molecular strategies in response to soil contaminants

过去和目前的工业活动，如采矿和石化精炼，对环境产生了重大有害影响，在加拿大各地留下了大片退化和受污染的土地。大多数受污染的场地既受到有机化合物的影响，也受到无机化合物的影响。主要的有机污染物包括石油副产品、挥发性有机化合物、芳香烃和杀虫剂。常见的无机污染物是金属和类金属，称为痕量元素。植物修复是一种环境技术，旨在利用植物中的这些自然机制及其与土壤污染物积累或降解相关的特性。对于生长在这种污染土壤中的植物来说，潜在的有毒污染物会引起生理和分子变化，这是非生物胁迫的特征。尽管它们的共同出现是众所周知的，但它们各自的作用和顺序(前置因素、机制和产出)仍然描述得很少。*我的研究计划的长期目标是了解植物如何在受污染的土壤上生长。该计划的一般假设是，植物诱导代谢途径，从而改变生理过程，使它们能够耐受、提取或降解污染物，以响应土壤污染物诱导的非生物胁迫，并且这些途径可以是特定的，也可以在物种之间共享。*利用下一代测序的最新进展，我将使用一种基于田间实验和受控环境的策略来探索在受污染土壤中生长的植物的转录本和生理学。该项目的具体目标是：1)描述在受污染的土壤环境中建立快速生长的先锋植物的转录效应；2)评估根基因表达的变化是否反映在渗透调节、次生代谢产物和根际生物学等改变的生理机制中。这种结合的方法应该能够利用在受控温室试验中获得的结果来分离田间条件所固有的环境变量。该计划的每个目标都将在我的监督下分配给一名实习生。*这项研究计划将有助于我们理解植物对非生物胁迫，特别是对土壤污染的反应。这一研究计划的潜在应用是开发可用作土壤污染指示的分子生物标记物，并为植物选择提供依据，这些知识可以促进植物修复的发展，使其成为适合生态系统修复的有吸引力的选择。

Past and current industrial activities, such as mining and petrochemical refinement, have had major deleterious effects on the environment, leaving large areas of degraded and contaminated lands throughout Canada. The majority of contaminated sites is affected by both organic and inorganic compounds. The predominant organic contaminants include petroleum by-products, volatile organic compounds, aromatic hydrocarbons and pesticides. Common inorganic contaminants are metals and metalloids, referred to as trace elements. Phytoremediation is the environmental technique that aims to take advantage of these natural mechanisms in plants and of their associated properties of accumulation or degradation of soil contaminants. For plants growing in such polluted soils the potentially toxic contaminants induce physiological and molecular changes that are characteristic of abiotic stress. Although their co-occurrence is well known, their respective role and sequence (antecedent, mechanism and output) remain poorly described. ******The long-term goal of my research program is to understand how plants grow on contaminated soils. The general hypothesis of this program is that plants induce metabolic pathways that alter physiological processes allowing them to tolerate, extract or degrade contaminants in response to the abiotic stress induced by soil pollutants, and that these pathways can be specific or shared between species. ******Taking advantage of recent advances in next generation sequencing, I will use a strategy based on both field experiments and controlled environments to explore the transcriptomes and physiology of plants growing in contaminated soils. The specific objectives of this project are to: 1) Describe the transcriptomic effects of establishing fast-growing pioneer plant species in contaminated soil environments and, 2) evaluate if the changes in root gene expression are reflected in altered physiological mechanisms such as osmotic regulation, secondary metabolites and rhizosphere biology. This combined approach should allow the separation the environmental variables inherent to field conditions by taking advantage of the results obtained in controlled greenhouse experiments. Each of the objectives of the program will be assigned to a trainee under my supervision. ******This research program will contribute to our understanding of the plant responses to abiotic stresses and to soil contamination in particular. The potential applications of this research program are to develop molecular biomarkers that can be used as indicators of soil contamination as well as provide a basis for plant selection, knowledge which can advance the development of phytoremediation in order to make it a suitable attractive option for ecosystem rehabilitation.