Molecular mechanisms of oxidative stress tolerance in plants

植物抗氧化胁迫的分子机制

• 批准号: 138557-2012
• 负责人: Houde, Mario
• 金额: $ 1.89万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569362
• 关键词: Molecular; mechanisms; oxidative; stress; tolerance

Each year Canada loses hundreds of millions of dollars from loss in crop productivity caused by different environmental stresses. Oxidative stress is a common response to different stresses such as heat, cold, high-light, drought, osmotic shock, wounding, UV-B radiation, ozone, aluminum and pathogens. Our studies on aluminum stress and tolerance allowed us to identify several genes that could play an important role in regulating plant responses to oxidative stress. Improving tolerance to this stress will likely enhance plant fitness by increasing cross-tolerance to a variety of stresses. To achieve this goal, we will: I) Characterize the regulatory factors involved in oxidative stress responses and their potential function in improving tolerance to reactive oxygen species (ROS). We have recently identified two Zinc finger transcription factor family members which expression is significantly associated with Al tolerance in near-isogenic wheat lines. These transcription factors are also responsive to different sources of oxidative stress such as H2O2 and hydroxyl radicals. Characterization of these wheat transcription factors and their upstream factors will help to understand their mechanisms of regulation. Over-expression of these factors in transgenic lines will confirm whether they can improve tolerance to aluminum and other ROS in either roots or leaves. II) Determine the function of key energy pathway regulatory genes involved in ROS detoxification. Among these genes, some encode enzymes (e.g. fructose-1,6-bisphosphatase and glucose-6-phosphate dehydrogenase) involved in the regulation of key energy pathways involved in the regeneration of antioxidant molecules. The effect of regulating these genes will be studied using transgenic plant models to evaluate their ability to produce antioxidant molecules and to tolerate oxidative stress. Understanding the regulatory mechanisms involved in oxidative stress tolerance will lead to the development of appropriate strategies for crop improvement allowing plants to withstand a variety of stresses. This will result in improved plant fitness and productivity.

加拿大每年因不同的环境压力造成的作物生产力损失而损失数亿美元。氧化胁迫是植物对热、冷、强光、干旱、渗透压休克、创伤、UV-B辐射、臭氧、铝和病原体等不同胁迫的共同反应。我们对铝胁迫和耐受性的研究使我们能够确定几个基因，这些基因可能在调节植物对氧化胁迫的反应中发挥重要作用。提高对这种胁迫的耐受性将可能通过增加对各种胁迫的交叉耐受性来增强植物适应性。为了实现这一目标，我们将： I）表征参与氧化应激反应的调节因子及其在改善对活性氧（ROS）的耐受性中的潜在功能。我们最近鉴定了两个锌指转录因子家族成员，它们的表达与近等基因小麦耐铝性显著相关。这些转录因子也响应于不同来源的氧化应激，如H2 O2和羟基自由基。这些小麦转录因子及其上游因子的特性将有助于了解其调控机制。这些因子在转基因株系中的过表达将证实它们是否可以提高根或叶中对铝和其他ROS的耐受性。 II）确定参与ROS解毒的关键能量途径调控基因的功能。在这些基因中，一些编码酶（如果糖-1，6-二磷酸酶和葡萄糖-6-磷酸脱氢酶），这些酶参与调节抗氧化分子再生中的关键能量途径。调节这些基因的效果将使用转基因植物模型进行研究，以评估它们产生抗氧化分子和耐受氧化应激的能力。 了解参与氧化胁迫耐受性的调节机制将导致作物改良的适当策略的发展，使植物能够承受各种压力。这将提高植物的适应性和生产力。