Molecular Dissection of Autophagy in Maize and its Roles in Nutrient Recycling and Stress Protection

玉米自噬的分子解剖及其在养分循环和应激保护中的作用

• 批准号: 1339325
• 负责人: Marisa Otegui
• 金额: $ 96.9万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-12-15 至 2019-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1339325&HistoricalAwards=false
• 关键词: Molecular; Dissection; Autophagy; Maize; its

PI: Richard D. Vierstra (University of Wisconsin - Madison)CoPI: Marisa S. Otegui (University of Wisconsin - Madison)Plants employ sophisticated mechanisms to traffic and recycle intracellular constituents needed for growth and development, housekeeping, and survival under nutrient stress. One involves the sequestration of cytoplasmic material in autophagic vesicles and subsequent delivery of these vesicles to the vacuole for breakdown or storage. Prior work made substantial progress toward defining the mechanisms underpinning autophagy through molecular, genetic, and imaging analyses of a set of essential autophagy-related (ATG) components in both Arabidopsis and maize. Of relevance to agriculture were recent findings that autophagy is critical to nitrogen-use efficiency in maize and the discovery of a novel autophagic route that operates in maize seeds. The objectives of this project are to: (i) further define the maize ATG system at the biochemical and genetic levels; (ii) provide an integrated view of how autophagy impacts maize growth, development, and yield during nitrogen stress by combining atg mutants with phenotypic, cell biological, proteomic, metabolomic, and transcriptomic analyses; (iii) identify the cargo degraded by autophagy via proteomic characterizations of autophagic vesicles; and (iv) define the molecular mechanism underpinning ATG-independent autophagy during maize seed protein accumulation. Collectively, this research will provide the first systems view of autophagy in a crop plant and its role in nitrogen-use efficiency. More broadly, this research will also generate important reagents, techniques, mutants, transgenic lines, germplasm, and cargo catalogs that will provide a much needed foundation to appreciate autophagy in the important crop, maize. With such knowledge, it should be possible to re-engineer crops that more efficiently use nitrogen and other nutrients, that better remobilize these nutrients to areas of new growth and storage, that display improved leaf senescence and fruit ripening characteristics, and that provide better grain yields.As a broader impact, this project is designed to provide an interdisciplinary vehicle for training the next generation of plant scientists using state-of-the-art genetic, proteomic, transcriptomic, metabolomic, and cell biological approaches to study crop physiology. Participants include research scientists, graduate students, and several undergraduates at Wisconsin or attending the UW-summer REU experience hosted by the Integrated Biological Sciences Summer Research Program, as well as high school students sponsored by the Wisconsin Youth Apprenticeship Program (YAP) in Biotechnology. YAP-Biotechnology is designed to expand the workforce in biological sciences by providing practical training to high school juniors and seniors through formal technology classes combined with real-life research experiences. Additional educational impacts involve cell biology workshops developed by the CoPI, who serves as the supervisor of the NSF-sponsored Plant Imaging Center, related to the next generation tomographic imaging techniques that will be refined during this project. Some of these refinements will be developed through an Introduction to Engineering Design course project organized by the UW-School of Engineering that will create devices optimized for imaging maize endosperms. Free and unencumbered public access to the RNA-seq, metabolomic, and proteomic datasets generated by this project will be facilitated by deposition of the data at MaizeGDB (http://www.maizegdb.org/) and the NCBI Gene Expression Omnibus (GEO; http://www.ncbi.nlm.nih.gov/geo/) public repositories. Mutant germplasm and stable transgenic lines will be made available through the Maize Genetics Cooperative Stock Center (http://maizecoop.cropsci.uiuc.edu).

PI: Richard D. Vierstra（威斯康星大学麦迪逊分校）CoPI: Marisa S. Otegui（威斯康星大学麦迪逊分校）植物利用复杂的机制来运输和循环细胞内成分，这些成分是生长发育、内务管理和在营养胁迫下生存所必需的。一种是将细胞质物质隔离在自噬小泡中，随后将这些小泡运送到液泡中进行分解或储存。先前的工作通过对拟南芥和玉米中一系列基本自噬相关（ATG）成分的分子、遗传和成像分析，在定义自噬机制方面取得了实质性进展。与农业相关的最新研究发现，自噬对玉米的氮利用效率至关重要，并发现了一种在玉米种子中起作用的新型自噬途径。该项目的目标是：(i)在生化和遗传水平上进一步确定玉米ATG系统；（ii）通过将突变体与表型、细胞生物学、蛋白质组学、代谢组学和转录组学分析相结合，提供氮胁迫下自噬如何影响玉米生长、发育和产量的综合观点；（iii）通过自噬囊泡的蛋白质组学特征识别自噬降解的货物；（iv）确定玉米种子蛋白质积累过程中不依赖atg的自噬的分子机制。总的来说，这项研究将提供作物植物自噬及其在氮利用效率中的作用的第一个系统观点。更广泛地说，这项研究还将产生重要的试剂、技术、突变体、转基因品系、种质和货物目录，这些将为了解重要作物玉米的自噬提供急需的基础。有了这些知识，就有可能重新设计作物，更有效地利用氮和其他营养物质，更好地将这些营养物质重新调动到新的生长和储存区域，表现出更好的叶片衰老和果实成熟特征，并提供更好的粮食产量。作为一个更广泛的影响，该项目旨在提供一个跨学科的工具，培训下一代植物科学家使用最先进的遗传，蛋白质组学，转录组学，代谢组学和细胞生物学方法来研究作物生理学。参与者包括研究科学家、研究生和威斯康星大学的几名本科生，或参加由综合生物科学夏季研究计划主办的威斯康星大学夏季REU体验，以及由威斯康星青年学徒计划（YAP）赞助的高中学生。YAP-Biotechnology旨在通过正式的技术课程结合实际研究经验，为高中三年级和四年级学生提供实践培训，从而扩大生物科学领域的劳动力。额外的教育影响包括由美国国家科学基金会（nsf）赞助的植物成像中心的主管CoPI开发的细胞生物学研讨会，涉及将在该项目中改进的下一代层析成像技术。其中一些改进将通过由威斯康星大学工程学院组织的工程设计导论课程项目来开发，该课程将创建用于玉米胚乳成像的优化设备。通过将数据存储在MaizeGDB （http://www.maizegdb.org/）和NCBI Gene Expression Omnibus （GEO; http://www.ncbi.nlm.nih.gov/geo/）公共存储库，可以方便公众免费、无阻碍地访问该项目生成的RNA-seq、代谢组学和蛋白质组学数据集。突变种质和稳定的转基因品系将通过玉米遗传合作库存中心（http://maizecoop.cropsci.uiuc.edu）提供。