Roles of subcellular amino acid transporters in source and sink function

亚细胞氨基酸转运蛋白在源库功能中的作用

• 批准号: 1932661
• 负责人: Mechthild Tegeder
• 金额: $ 66.48万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1932661&HistoricalAwards=false
• 关键词: Roles; subcellular; amino; acid; transporters

Plants require large amounts of nitrogen for growth and development. The nitrogen is generally taken up from the soil and then used to produce amino acids. These amino acids play highly diverse and essential roles in plants. They are the basic units of proteins and enzymes, and thereby fundamental to cellular structure and metabolism. Moreover, they are crucial for the synthesis of a large variety of compounds, such as chlorophyll, vitamins and other products needed for plant function as well as for human nutrition. In addition, amino acids serve as signaling molecules triggering physiological processes including plant responses to environmental stresses, and they present the main long-distance nitrogen forms transported to seeds for growth. This project intends to provide pioneering insights on the mechanisms of amino acid partitioning within the cell and their importance for leaf and seed development, and plant survival. It is expected to discover strategies on how amino acid movement can be manipulated to alter nitrogen supply into specific metabolic and transport pathways, with consequences for plant growth, productivity and responses to environmental stresses. The activities will further promote student teaching and training, and foster effective integration of plant biology education and research.A fundamental process in plants is the selective partitioning of amino acids among different organelles, cells, tissues and organs. Various transport mechanisms must exist within the cell to accommodate their directional transport, and these mechanisms must be coordinated and regulated at different levels to achieve normal physiological functions. In Arabidopsis, more than 100 putative amino acid transporters have been identified but physiological functions in nitrogen transport have only been demonstrated for relatively few transporters, and these are mainly plasma membrane-localized. This project intends to identify novel subcellular amino acid transporters and resolve their substrate specificity and mechanisms of transport. Plants, in which the transporters are knocked-out, knocked-down or overexpressed will be analyzed using molecular, cell-biological and biochemical approaches to unravel the physiological functions of the membrane proteins and their importance for plant growth and development. Finally, amino acids have been shown to play important roles in plant performance under environmental stress conditions. The transporter mutants or overexpressors will be exposed to abiotic stresses and their responses will be examined. Together, this project will help to resolve the function of intracellular membrane transporters and their role in nitrogen partitioning between cellular compartments to promote source leaf function, and in long distance amino acid transport in support of seed development. Evidence will be found on how specific amino acid transporters interconnect nitrogen and carbon metabolism, and other biochemical pathways, and if and how they influence plant responses to abiotic stress.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.

植物的生长发育需要大量的氮。氮通常从土壤中吸收，然后用来生产氨基酸。这些氨基酸在植物中发挥着高度多样化和重要的作用。它们是蛋白质和酶的基本单位，因此是细胞结构和代谢的基础。此外，它们对多种化合物的合成至关重要，如叶绿素、维生素和其他植物功能和人体营养所需的产品。此外，氨基酸是触发包括植物对环境胁迫反应在内的生理过程的信号分子，它们是向种子输送生长所需的长距离氮的主要形式。该项目旨在为细胞内氨基酸分配机制及其对叶片和种子发育和植物存活的重要性提供开创性的见解。该研究有望发现如何操纵氨基酸运动以改变氮供应进入特定代谢和运输途径的策略，从而影响植物的生长、生产力和对环境胁迫的反应。这些活动将进一步促进学生的教学和培训，促进植物生物学教育与研究的有效结合。植物的一个基本过程是氨基酸在不同细胞器、细胞、组织和器官之间的选择性分配。细胞内必须存在多种运输机制以适应其定向运输，这些机制必须在不同水平上进行协调和调节，才能实现正常的生理功能。在拟南芥中，已经确定了100多种假定的氨基酸转运蛋白，但仅证明了相对较少的转运蛋白在氮转运中的生理功能，这些转运蛋白主要是质膜定位的。本项目旨在鉴定新的亚细胞氨基酸转运蛋白，并确定其底物特异性和转运机制。在转运蛋白被敲除、敲低或过表达的植物中，将使用分子、细胞生物学和生化方法来分析膜蛋白的生理功能及其对植物生长发育的重要性。最后，氨基酸已被证明在环境胁迫条件下对植物的生产性能起重要作用。转运体突变体或过表达体将暴露于非生物胁迫下，并检测其反应。总之，该项目将有助于解决细胞膜内转运蛋白的功能及其在细胞间氮分配中促进源叶功能的作用，以及在支持种子发育的长距离氨基酸运输中的作用。证据将发现特定的氨基酸转运体如何连接氮和碳代谢，以及其他生化途径，以及它们是否以及如何影响植物对非生物胁迫的反应。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

A Research Road Map for Responsible Use of Agricultural Nitrogen

• DOI: 10.3389/fsufs.2021.660155
• 发表时间: 2021-05
• 作者: M. Udvardi;F. Below;M. Castellano;Alison J Eagle;K. Giller;J. Ladha;Xuejun Liu;T. Maaz;Bárbara Nova-Franco;N. Raghuram;G. Robertson;Sonali Roy;M. Saha;S. Schmidt;M. Tegeder;L. York;J. W. Peters