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

检测和响应胁迫的能力是植物在一系列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给予各种非生物和生物挑战特定保护的途径，但最近发现了一种潜在的普遍保护机制，涉及到小泛素相关修饰物(SUMO)，这可能会改变目前对应激生物学的认识。具体地说，研究表明，拟南芥相扑多肽与许多核蛋白发生共价连接，并且在植物受到各种非生物胁迫后，这些结合物的水平迅速且可逆地上升。利用新的定量蛋白质组学方法，人们发现许多SUMO化靶标是已知的关键调控因子，它们的共同功能意味着相扑加成参与了一种保护性反应，从而广泛地改变了染色质的可及性、转录和mRNA的加工/输出。综上所述，这些结果表明，相扑运动可能提供了独特的机会，在全球范围内操纵压力反应，以获取农业利益。不幸的是，相扑系统的组织和功能在其他植物物种中很大程度上是未知的，包括所有重要的农作物，因此无法进行合理的重新设计来提高作物的生产力。此外，对玉米和水稻的初步基因组分析表明，谷物中相扑系统的组织可能与拟南芥中观察到的组织显著不同。这个迫切的项目建议以玉米(Zea Mays)为模型，定义作物在逆境期间SUMO化是如何发挥作用的。其具体目标是：(I)利用生物信息学和生化方法描述玉米的SUMO化系统，并从动力学上确定该系统如何响应逆境；(Ii)建立影响相扑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”，量化单个目标的SUMOylome状态在胁迫期间和恢复后的变化；以及(Iv)分析SUMO途径突变的表型，以确定胁迫诱导的SUMO化如何帮助玉米在不利环境中生存。总而言之，这个项目将产生急需的工具和种质，可以用来了解相扑如何在逆境中重组玉米染色质及其转录组，并确定涉及SUMO化的植物胁迫反应中的关键点，这些关键点可以被操纵以提高产量。目前对植物SUMO化的了解仍然很初级，几乎不存在于作物物种中，因为它的操纵可能会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。这项研究将包括由威斯康星州青年学徒计划(YAP)赞助的生物技术博士后、研究生和本科生以及高中生。在这个项目的过程中，将产生试剂、技术、突变体和转基因品系，这将为研究玉米的SUMO化提供急需的基础，并有望为合理改变相扑系统的农业和医药效益提供新的策略。植物资源将通过玉米遗传合作社库存中心(http://maizecoop.cropsci.uiuc.edu).)获得原始和处理的实验数据将存储在美国国家实验室的基因表达总览(GEO)和玉米GDB(http://www.maizegdb.org/).)中

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/).