Interactions of plants with the environment: impacts of contaminants on plants and phytoremediation of contaminants

植物暴露于许多环境压力源，包括污染物，如多环芳烃（PAH），石油烃（PHCs），金属，盐和农药。这些污染物中的大多数在环境相关浓度下对植物是有毒的，并且许多通过活性氧（ROS）起作用。当了解毒性机制时，可以建立缓解压力的策略，提高植物用于土壤修复（植物修复）的机会。我的研究项目中有两个正在进行的项目涉及植物如何与污染物相互作用。1)植物毒性的机制：我们已经表明，多环芳烃，氧化多环芳烃，PHCs，金属和盐是植物毒性。这些化合物通常通过ROS机制影响光合作用。为了更好地了解植物毒性的机制，我们将研究多环芳烃和金属对芸苔属，浮萍和拟南芥光合作用的影响。我们还发现，多环芳烃，金属和UVB激活许多相同的驯化过程通过活性氧和氧化还原信号通路。因此，我们将通过ROS清除酶和类黄酮的积累，以及ROS和氧化还原诱导的基因表达来研究驯化。2)优化植物修复：修复工业场地的持久性污染物（例如，在污染（如棕地和威尔斯油井）的情况下，开发有效和对环境负责的补救技术，如植物补救，至关重要。虽然植物的根可以清除土壤中的污染物，但这些污染物通常会导致植物胁迫，阻碍生长。基于我们以上的毒理学工作，我们可以完善现有的植物修复策略，以提高受影响土壤的植物耐受性。我们正在开发的系统的关键是用促进植物生长的根际细菌减轻植物胁迫。为了使这些系统更有效，我们需要更好地了解植物修复过程中的植物胁迫和驯化机制。要做到这一点，我们将研究植物修复过程中的性能的草种和谷物的PHC和盐利用光合作用，类黄酮成分，ROS清除能力和基因表达的驯化和应力的措施。

Plants are exposed to numerous environmental stressors including contaminants such as polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), metals, salt and pesticides. Most of these contaminants are toxic to plants at environmentally relevant concentrations, and many act through reactive oxygen species (ROS). When the mechanisms of toxicity are understood, a strategy to alleviate stress can be established, improving the chances that plants can be used for soil remediation (phytoremediation). Two ongoing projects in my research program pertain to how plants interact with contaminants. 1) Mechanisms of Phytotoxicity: We have shown that PAHs, oxyPAHs, PHCs, metals and salt are phytotoxic. These compounds impact on photosynthesis, often via ROS mechanisms. To better understand mechanisms of phytotoxicity, we will examine the effects of PAHs and metals on photosynthesis in Brassica, Lemna and Arabidopsis. We also found that PAHs, metals and UVB activate many of the same acclimation processes via ROS and redox signaling pathways. Thus, we will examine acclimation via accumulation of ROS scavenging enzymes and flavonoids, as well as ROS and redox induced gene expression. 2) Optimization of Phytoremediation: To remediate persistent contaminants from industrial sites (e.g., brownfields and oil wells), development of effective and environmentally responsible remediation technologies such as phytoremediation are crucial. Although plant roots can remove contaminants from soil, these contaminants often cause plant stress, impeding growth. Based on our toxicology work above, we can refine existing phytoremediation strategies to improve plant tolerance in impacted soils. The key to the systems we are developing is the alleviation of plant stress with plant growth promoting rhizobacteria. To make these systems more effective we need to better understand the mechanisms of plant stress and acclimation during phytoremediation. To do this we will study the performance of grass species and cereals during phytoremediation of PHC and salt using photosynthesis, flavonoid composition, ROS scavenging capacity and gene expression as measures of acclimation and stress.