RUI: Mitochondrial Ferropotin and Iron Homeostasis in Plants

铁是几乎所有生命形式所必需的矿物质营养素。然而，当细胞中存在过量的铁时，或者当铁没有在细胞内的适当位置时，铁是潜在的有毒物质。因此，铁必须受到微妙的分子机制的严格控制。研究铁是如何在植物中调节的，不仅将提供基本的科学见解，还将提供潜在的战略，以提高植物的营养质量，以改善农业和人类营养。虽然卡路里营养不良已显著减少，但必需矿物质营养不良仍很普遍。特别是，铁缺乏影响着世界上近一半的人口。植物是世界范围内铁的主要饮食来源，但它们并不富含铁。生物强化，即提高作物营养价值的过程，是一种很有希望的战略，可以为营养不良提供可持续的解决方案。铁是植物必需的营养物质。然而，由于土壤中的铁不容易被植物吸收，它是植物生长的第三大限制养分。因此，这项拟议的工作具有广泛的影响，因为了解铁在植物中的运输是改善植物生长、作物产量和人类营养的关键。该项目将为阿默斯特学院的本科生提供研究经验。此外，该项目还将支持一项正在进行的推广活动，为当地一所公立小学的五年级学生开发动手分子生物学模块。细胞铁稳态的一项关键任务是安全地将铁分配到特定的细胞器中使用或储存。线粒体对铁的营养特别重要。必要的代谢过程，如呼吸，需要铁，但线粒体非常容易受到铁诱导的氧化损伤。尽管线粒体中铁的重要性，但线粒体铁在植物中的运输还不是很清楚。这项拟议的工作旨在通过研究线粒体铁孔蛋白(FPN)在拟南芥中的作用来了解铁的动态平衡。FPN在脊椎动物中得到了很好的研究，但在植物中几乎没有特征。此外，线粒体FPN是独一无二的，因为还没有发现其他线粒体FPN。在这项研究中，将调查铁运输的方向性，以验证FPN3是线粒体铁输出器的假设。最终，这项研究的目的是了解FPN3的生物学作用。因此，这项研究建议通过分析fpn3功能丧失的拟南芥突变体来测试fpn3是否释放线粒体铁用于细胞质和/或用于保护免受氧化胁迫。这项拟议的工作将揭开线粒体FPN3的细胞和生理作用，并有助于更全面地了解植物铁的自我调节。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Iron is an essential mineral nutrient required for virtually all forms of life. However, iron is potentially toxic when an excess amount of iron is present in the cell, or when iron is not in the proper location within the cell. Therefore, iron must be tightly controlled by delicate molecular mechanisms. Studying how iron is regulated in plants will not only provide fundamental scientific insights, but also provide potential strategies to enhance the nutritional quality of plants to improve agriculture and human nutrition. While caloric malnutrition has significantly decreased, malnutrition of essential mineral nutrients is still prevalent. In particular, iron deficiency affects nearly half of the world's population. Plants are the primary dietary source of iron worldwide, but they are not rich in iron. Biofortification, the process of enhancing the nutritional value of crops is a promising strategy that could provide a sustainable solution to malnutrition. Iron is a required nutrient for plants. However, because iron in the soil cannot readily be absorbed by plants, it is the third most limiting nutrient for plant growth. Therefore, the proposed work is of broad impact, as understanding iron transport in plants is key to improving plant growth, crop yields, and human nutrition. The project will provide research experiences for undergraduate students at Amherst College. In addition, an ongoing outreach activity to develop hands-on molecular biology modules for 5th graders at a local public elementary school will be supported by the project.A key task in cellular iron homeostasis is to safely allocate iron to specific organelles for usage or storage. Mitochondria are of particular interest for iron nutrition. Essential metabolic processes, such as respiration, require iron, but mitochondria are highly susceptible to iron-induced oxidative damage. Despite the significance of iron in mitochondria, mitochondrial iron transport is not well understood in plants. The proposed work aims to understand iron homeostasis by investigating the role of a mitochondrial ferroportin (FPN) in Arabidopsis thaliana. FPNs are well-studied in vertebrates, yet hardly characterized in plants. Moreover, mitochondrial FPN is unique, as no other mitochondrial FPN has been identified. In this study, the directionality of iron transport will be investigated to test the hypothesis that FPN3 is a mitochondrial iron exporter. Ultimately, this study aims to understand the biological role of FPN3. Therefore, this study proposes to test if FPN3 release mitochondrial iron for use in the cytoplasm and/or for protection against oxidative stress, by analyzing fpn3 loss-of-function Arabidopsis mutants. The proposed work will unravel the cellular and physiological role of a mitochondrial FPN3 and contribute to a more comprehensive understanding of plant iron homeostasis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.