Metabolic and signaling interactions between plant mitochondria and chloroplasts

植物线粒体和叶绿体之间的代谢和信号相互作用

• 批准号: RGPIN-2019-04362
• 负责人: Vanlerberghe, Greg
• 金额: $ 3.42万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689527
• 关键词: Metabolic; signaling; interactions; between; plant

Crop growth and productivity depends on the capacity of plant metabolism to function effectively over the wide range of environmental conditions experienced in the field. A core theme of worldwide efforts to improve crop yield is the need to better understand how metabolism functions, particularly under the less favorable (stress) conditions that are expected to become more prevalent in the future. Hence, my research program investigates the impact of key abiotic and biotic stresses, as well as global change factors such as elevated atmospheric concentrations of CO2, on metabolism. The goal is to uncover the signature responses of carbon and energy metabolism to stress, to elucidate how these responses support acclimation to stress, and to generate the knowledge foundation required to improve metabolic function and plant performance under stress. Emphasis is on the two major energy-transducing organelles of the plant cell (the mitochondrion and the chloroplast) and on the interactions that occur between major metabolic hubs including respiration, photosynthesis and nutrient assimilation. In addition, the impact of the related reactive oxygen and reactive nitrogen metabolic networks is investigated. These reactive species can damage metabolism but are also key signaling molecules supporting growth, development and stress acclimation. To achieve our goals, an integrative approach is taken, whereby processes are studied at the whole plant, cell and organelle levels using a combination of physiological, biochemical and molecular biological approaches. The proposed research will provide mentorship and training to seven graduate students (4 Ph.D, 3 M.Sc.) and numerous undergraduate students. This will include a fostering of independence and multidisciplinary approaches, while working in a supportive and inclusive environment.******Alternative oxidase (AOX) is a metabolic component that reduces energy yield in plant respiration. Despite key advances in understanding the genetic and biochemical control of AOX, its role in metabolism and its overall impact on plant performance remains poorly understood. This represents a major gap in our understanding of primary metabolism. AOX gene expression is highly responsive to environmental cues and evidence indicates that it may be of particular importance under variable and stress conditions. Theoretically, AOX should negatively affect growth since it reduces energy yield. However, it may have key roles in metabolism and mitochondrial function that outweigh this energy cost. We hypothesize that, while AOX is a respiratory component, it interacts extensively with chloroplast photosynthesis. These interactions, in turn, improve photosynthetic performance. To test this hypothesis, plants with increased or decreased AOX amount can be compared to wild-type plants. Plant growth and metabolism can be characterized under a range of environmental and stress conditions, and in both controlled-environment and field settings. **

农作物的生长和生产率取决于植物代谢在该领域经历的各种环境条件下有效发挥作用的能力。全球提高农作物产量的核心主题是需要更好地了解新陈代谢的功能，尤其是在未来预计将变得更加普遍的较不利的（压力）条件下。因此，我的研究计划研究了关键的非生物和生物胁迫的影响，以及全球变化因素，例如二氧化碳的大气浓度升高对代谢。目的是发现碳和能量代谢对压力的签名反应，以阐明这些响应如何支持压力的适应，并产生在压力下改善新陈代谢功能和植物表现所需的知识基础。重点放在植物细胞的两个主要能量传递细胞器上（线粒体和叶绿体）以及主要代谢中心之间发生的相互作用，包括呼吸，光合作用和营养同化。此外，研究了相关的活性氧和反应性氮代谢网络的影响。这些反应性物种会损害新陈代谢，但也是支持生长，发育和压力适应的关键信号分子。为了实现我们的目标，采取了一种综合方法，在该方法中，通过生理，生化和分子生物学方法的结合在整个植物，细胞和细胞器水平上研究过程。拟议的研究将为七位研究生（4博士学位，3硕士）和众多本科生提供指导和培训。这将包括在支持性和包容性环境中工作时的独立性和多学科方法。******替代氧化酶（AOX）是一种代谢成分，可降低植物呼吸中的能量产量。尽管了解AOX的遗传和生化控制方面的关键进展，但其在代谢中的作用及其对植物性能的总体影响仍然很少了解。这代表了我们对主要代谢的理解的主要差距。 AOX基因表达对环境线索的反应很高，证据表明，在可变和应力条件下，它可能特别重要。从理论上讲，AOX应对生长产生负面影响，因为它会降低能量产量。但是，它可能在代谢和线粒体功能中具有关键作用，使能量成本超过了。我们假设，尽管AOX是一种呼吸系统，但它与叶绿体光合作用相互作用。这些相互作用反过来改善了光合作用的性能。为了检验这一假设，可以将具有增加或减少量的植物与野生型植物进行比较。植物生长和代谢可以在各种环境和应力条件下以及受控环境和现场设置中进行表征。 **