A Systems Biology-aided Investigation of Pathogen-mediated Manipulation of Sugar Metabolism in Arabidopsis

植物-微生物致病系统构成了一个非常复杂的生物网络，其中来自病原体和宿主的分子参与了一场争夺优势的战斗。专门的病原体已经进化出一套称为效应子的分子，它们调节宿主细胞的生理学并支持寄生。在过去的几十年里，大量的文献已经记录了诱导有效免疫应答和破坏效应子介导的宿主防御的分子机制。然而，一个尚未解决的关键问题是病原体如何改变细胞代谢，包括操纵源-库关系，以获得营养。这个跨学科项目通过整合生物学和快速发展的计算机科学领域，大大超越了湿实验室技术，以促进研究，教育和社区科学参与。机制的理解效应介导的扰动，以调动糖从中央液泡将追求。阐明病原体感染如何调节全球转录动力学和改变生物信息流是主要焦点。同样重要的是，将揭示代谢、激素、昼夜节律和免疫信号传导途径之间的相互作用，包括来自致病性和非致病性细菌菌株的信号。该项目位于亚拉巴马的中心，在一所国家认可的多样性大学，该项目的范围延伸到教育途径，因为高级基因组学课程的学生将获得相关生物信息学分析的经验，PI领导的BioTeach计划的城市高中教师将接触到当今的遗传创新，积极的招生工作将寻求吸引邻近的HBCU少数民族学生。这项建议的核心框架，了解植物病原体如何通过其效应器的毒力活动获得糖，提出了一个实质性的进步，超过了以前的限制尺寸的一个病原体：一个蛋白质的分析方法。具体来说，该项目的重点是病原体效应子HopD 1，其与一组宿主蛋白质物理相互作用，形成一个功能模块，称为“液泡转化酶（Vac-INV）模块”。HopD 1干扰Vac-INV模块以动员储存在中央液泡中的糖，同时减缓质外体糖再吸收到宿主细胞中的机制将被研究。还将研究HopD 1通过干扰保守的水通道蛋白介导的气孔调节机制来抑制免疫应答。基于Vac-INV？通过对转录通路的依赖，构建了植物-病原菌互作的高分辨率全局动态转录调控网络。该项目已经开发了一个用于启动子和生物信息学分析的基于网络的界面OOCEAN，将继续在快速发展的系统生物学世界中扩展其实用性。基于网络生物学的新分析将有助于广泛了解单个效应子如何同时针对植物免疫和代谢的不同分支，以获得病原体的优势。这项工作也将导致一个系统，可以应用于其他重要的问题，有关植物防御和代谢以及。总的来说，这个系统级项目将巩固效应器-宿主相互作用，效应器介导的扰动，以及随后的动态转录调控的全球理解。

The plant-microbe pathosystem constitutes a very complex biological network in which the molecular players from both the pathogen and the host engage in a battle for dominance. Specialized pathogens have evolved suites of molecules called effectors that modulate host cell physiology and support parasitism. Over the past decades, a plethora of literature has documented the molecular mechanisms that underlie the induction of effective immune responses and subversion of effector-mediated host defenses. However, a key unresolved question is how pathogens alter cellular metabolism, including manipulation of the source-sink relationships, to acquire nutrients. This interdisciplinary project extends significantly beyond wet-lab techniques by integrating both biology and the rapidly evolving field of computer science for the advancement of research, education, and community-based scientific engagement. Mechanistic understanding of effector-mediated perturbations to mobilize sugars from the central vacuole will be pursued. Elucidating how pathogen infection modulates the global transcriptional dynamics and alters the flow of biological information is of prime focus. Equally paramount, cross-talk between metabolic, hormonal, circadian and immune signaling pathways, involving signals from pathogenic and non-pathogenic bacterial strains, will be revealed. Situated in the heart of Alabama, at a nationally recognized university for diversity, this project's scope extends into educational avenues as students in advanced level genomics courses will gain experience with relevant bioinformatic analyses, urban high school teachers in the PI's-led BioTeach program will gain exposure to the genetic innovations of today, and zealous recruiting efforts will seek to engage neighboring HBCU-minority students.The central framework of this proposal, understanding how plant pathogens acquire sugars through the virulence activities of their effectors, presents a substantial advancement over the previously limiting dimensions of a one pathogen: one protein analysis approach. Specifically, this project is focused on a pathogen effector, HopD1, that physically interacts with a set of host proteins forming a functional module, termed 'vacuolar invertase (Vac-INV) module.' The mechanisms by which HopD1 perturbs the Vac-INV module to mobilize sugars stored in the central vacuole while slowing down the resorption of apoplastic sugars into the host cell will be investigated. HopD1's immune response suppression through interference of a conserved aquaporin-mediated stomatal regulation mechanism will also be investigated. Based on the in silico modeling of Vac-INV?dependent transcriptional circuits, a high resolution global dynamic transcriptional regulatory network in plant-pathogen interactions will also also constructed. Having already developed a web-based interface, OOCEAN, for promoter and bioinformatics analyses, this project will continue to extend its utility in the fast-evolving world of Systems Biology. Novel network biology-based analyses will help obtain a broad understanding of how single effectors simultaneously target different branches of plant immunity and metabolism for the pathogen's advantage. This work will also result in a system that can be applied to other important questions pertaining to plant defense and metabolism as well. Collectively, this systems-level project will solidify global understanding of effector-host interactions, effector-mediated perturbations, and subsequently, dynamic transcriptional regulation.