EAGER: Defining the SUMOylation System in Maize and its Roles in Stress Protection

EAGER：定义玉米中的 SUMOylation 系统及其在应激保护中的作用

• 批准号: 1623467
• 负责人: Richard Vierstra
• 金额: $ 5.49万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1623467&HistoricalAwards=false
• 关键词: EAGER; Defining; SUMOylation; System; Maize

The ability to detect and respond to stress is central to a plant's survival in a host of unfavorable environments and a key determinant of agricultural productivity under sub-optimal field conditions. Although a number of pathways have been described that confer specific protection to various abiotic and biotic challenges, a recent discovery of a potentially universal protective mechanism involving the Small Ubiquitin-related MOdifier (SUMO) may transform the current appreciation of stress biology. Specifically, it has been shown that the Arabidopsis SUMO polypeptide becomes covalently attached to numerous nuclear proteins and that the levels of these conjugates rise rapidly and reversibly after exposing plants to various abiotic stresses. Using novel quantitative proteomic approaches, it has been discovered that many of the SUMOylation targets are known critical regulators with their collective functions implying that SUMO addition engages a protective response that broadly alters chromatin accessibility, transcription, and mRNA processing/export. Taken together, these results suggest that SUMO might offer unique opportunities to globally manipulate the stress response for agricultural benefit. Unfortunately, the organization and functions of the SUMO system are largely unknown in other plant species, including all important agricultural crops, thus precluding rational redesign to improve crop plant productivity. Moreover, preliminary genome analyses of maize and rice revealed that the organization of the SUMO system in cereals might differ significantly from that in observed in Arabidopsis. This EAGER project proposes to define how SUMOylation works during stress in crops using maize (Zea mays) as the model. The specific aims are to: (i) delineate the SUMOylation system in maize using bioinformatic and biochemical methods and define kinetically how the system responds to stress; (ii) generate a library of maize mutants and transgenic lines affecting key components required for SUMO addition and release; (iii) define the "SUMOylome" of maize, quantify how the SUMOylation status of individual targets changes during stress and after recovery; and (iv) analyze SUMO pathway mutants phenotypically to determine how stress-induced SUMOylation may help maize survive adverse environments. Collectively, this project will generate much-needed tools and germplasm that can be exploited to understand how SUMO might reorganize maize chromatin and its transcriptome during stress, and identify key points in plant stress responses involving SUMOylation that can be manipulated for improved yield.The current understanding of SUMOylation in plants is still rudimentary and almost nonexistent in crop species where its manipulation may have substantial agricultural impact. This project will provide interdisciplinary training of the next generation of plant scientists working on crops. This research will collectively incorporate postdocs, graduate students, and undergraduates as well as high school students sponsored by the Wisconsin Youth Apprenticeship Program (YAP) in Biotechnology. During the course of this project, reagents, techniques, mutants, and transgenic lines will be generated that will provide a much needed foundation to investigate SUMOylation in maize, and hopefully offer new strategies to rationally alter the SUMO system for agricultural and medicinal benefit. Plant resources will be available through the Maize Genetics Cooperative Stock Center (http://maizecoop.cropsci.uiuc.edu). Raw and processed experimental data will be deposited into NCBI's Gene Expression Omnibus (GEO) and at Maize GDB (http://www.maizegdb.org/).

检测和应对压力的能力是植物在许多不利环境中生存的核心，也是次优田间条件下农业生产力的关键决定因素。尽管已经描述了许多途径赋予对各种非生物和生物挑战的特定保护，但最近发现的一种涉及小泛素相关修饰因子（Small Ubiquitin-related MOdifier， SUMO）的潜在普遍保护机制可能会改变目前对应激生物学的认识。具体来说，已经证明拟南芥SUMO多肽与许多核蛋白共价结合，并且在植物暴露于各种非生物胁迫后，这些偶联物的水平迅速可逆地上升。使用新的定量蛋白质组学方法，已经发现许多SUMO化靶点是已知的关键调节因子，其集体功能意味着SUMO的添加参与了广泛改变染色质可及性、转录和mRNA加工/输出的保护性反应。综上所述，这些结果表明，SUMO可能提供了独特的机会，可以在全球范围内操纵胁迫反应，以实现农业效益。不幸的是，SUMO系统在其他植物物种（包括所有重要的农作物）中的组织和功能在很大程度上是未知的，因此无法进行合理的重新设计以提高作物的生产力。此外，玉米和水稻的初步基因组分析显示，谷物中SUMO系统的组织可能与在拟南芥中观察到的有显著差异。这个EAGER项目提出用玉米（Zea mays）作为模型来定义SUMOylation在作物胁迫下是如何工作的。具体目标是：(i)利用生物信息学和生化方法描述玉米中的SUMOylation系统，并从动力学角度定义该系统如何对胁迫作出反应；（ii）建立影响SUMO添加和释放所需关键成分的玉米突变体和转基因品系文库；（iii）定义玉米的“SUMOylome”，量化个体靶点的SUMOylome状态在胁迫和恢复后的变化；（iv）分析SUMO通路突变体的表型，以确定胁迫诱导的SUMO化如何帮助玉米在不利环境中生存。总的来说，该项目将产生急需的工具和种质，可以用来了解SUMO如何在胁迫下重组玉米染色质及其转录组，并确定植物胁迫反应中涉及SUMO化的关键点，这些关键点可以通过操纵SUMO化来提高产量。目前对植物中SUMOylation的了解仍处于初级阶段，在作物物种中几乎不存在，其操作可能对农业产生重大影响。该项目将为从事作物研究的下一代植物科学家提供跨学科培训。这项研究将由威斯康星青年学徒计划（YAP）资助的博士后、研究生、本科生以及高中生共同参与。在本项目的研究过程中，将产生相应的试剂、技术、突变体和转基因品系，为研究玉米SUMO修饰提供必要的基础，并有望为合理改变SUMO体系提供新的策略，以实现农业和药用效益。植物资源将通过玉米遗传合作库存中心（http://maizecoop.cropsci.uiuc.edu）获得。原始和处理过的实验数据将存入NCBI的基因表达综合数据库（GEO）和Maize GDB （http://www.maizegdb.org/）。