Integrating Signals in Iron Homeostasis

将信号整合到铁稳态中

• 批准号: 2343917
• 负责人: Mary Lou Guerinot
• 金额: $ 80.92万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343917&HistoricalAwards=false
• 关键词: Integrating; Signals; Iron; Homeostasis

Iron often limits plant growth and agricultural yield. Furthermore, more than 2 billion people are iron deficient because their plant-based diets are not a rich source of iron, making iron deficiency the most prevalent nutritional problem in the world today. Clearly, understanding iron metabolism in plants is crucial, both from the point of view of improving plant growth and crop yields, as well as improving human nutrition. Despite progress in tracing how iron moves throughout the plant, scientists still do not understand how plants integrate information about iron supply and light conditions. This project will help to explain how a protein called URI receives and then conveys information about both the iron status of a cell and light quality. In partnership with the New Hampshire Academy of Science, students in grades 6-12 will be offered research experiences that will raise their appreciation for all that plants do and teach them how to leverage the power of plants to ensure long term sustainability and health. NHAS runs summer and after school discovery-based scientific research programs for students from a wide geographic section of NH and VT. Their outreach covers rural areas where students generally have few opportunities to experience authentic scientific research. Broader impacts will also include training the next generation of scientists. Undergraduates from several different mentoring programs will participate in the proposed work.Iron is an essential nutrient for plants, yet too much iron can be toxic. Therefore, plants only take up iron when needed. The essential bHLH transcription factor, URI/bHLH121, is required for mounting the iron deficiency response. A phosphorylated form of URI accumulates under iron deficiency, forms heterodimers with subgroup bHLH IVc transcription factors and induces transcription of another class of transcription factors, the sub-group Ib bHLH. These Ib bHLH in turn heterodimerize with FIT/bHLH29, and drive the transcription of the genes encoding the iron transporter IRT1 and the ferric chelate reductase FRO2, to increase iron uptake. Although the mechanisms controlling iron uptake from the soil are now relatively well understood, little is known about how URI may integrate information about iron supply and light conditions. Light is required for URI phosphorylation, suggesting that a light-regulated kinase is involved. Genetic experiments were designed to determine whether URI phosphorylation is a red light or blue light response, and whether members of the photoregulatory kinase (PPK) family are involved. Experiments will also address a second point in the iron deficiency pathway where light information is required, namely the induction of the FIT transcription factor. The long-term goal is to understand the entire network of genes responsible for orchestrating a coordinated response to iron deficiency at the whole plant level. Such an understanding will transform efforts towards sustainable improvements of crop yields, in terms of plant productivity and nutrient content.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.

铁通常会限制植物的生长和农业产量。 此外，超过20亿人是铁缺乏的，因为他们的植物性饮食不是铁的丰富来源，这使铁缺乏成为当今世界上最普遍的营养问题。显然，从改善植物生长和作物产量的角度来看，了解植物中的铁代谢至关重要，以及改善人类营养。 尽管在追踪铁如何在整个植物中移动方面取得了进展，但科学家仍然不了解植物如何整合有关铁供应和光条件的信息。该项目将有助于解释称为URI的蛋白质如何接收的蛋白质，然后传达有关细胞的铁状态和光质量的信息。 与新罕布什尔州科学院合作，将为6 - 12年级的学生提供研究经验，这将提高对所有植物所做的事情的赞赏，并教他们如何利用植物的力量来确保长期的可持续性和健康。 NHAS夏季和校后，基于发现的科学研究计划，适用于NH和VT的广泛地理区域。他们的外展涵盖了农村地区，学生通常几乎没有机会体验真实的科学研究。 更广泛的影响还将包括培训下一代科学家。来自几个不同指导计划的本科生将参加拟议的工作。铁是植物的重要营养素，但铁太多可能是有毒的。 因此，植物只需要在需要时取铁。安装铁缺乏响应所需的必需BHLH转录因子URI/BHLH121是必需的。 URI的磷酸化形式在铁缺乏症下积累，形成了与亚组BHLH IVC转录因子的异二聚体，并诱导另一种转录因子的转录，亚组IB BHLH。这些IB BHLH又与FIT/BHLH29异二聚二聚体，并驱动编码铁转运蛋白IRT1和螯合螯合物还原酶FRO2的基因的转录，以增加铁的摄取。尽管现在已经相对充分地了解了从土壤中控制铁吸收的机制，但对于URI如何整合有关铁供应和光条件的信息知之甚少。 URI磷酸化需要光，表明涉及光激酶。 设计了遗传实验以确定URI磷酸化是红光还是蓝光反应，以及是否涉及光心理激酶（PPK）家族的成员。 实验还将解决需要光信息的铁缺乏途径中的第二点，即诱导拟合转录因子。长期的目标是了解负责在整个工厂水平上协调对铁缺乏症的协调反应的整个基因网络。这种理解将在植物生产力和养分含量方面将努力转化为可持续提高作物产量的努力。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估的评估来支持的。