Molecular genetic of Plant hormone signaling

摘要：植物激素是一组结构不相关的小分子，对植物的生长发育有着深远的影响。在过去的十年里，在确定许多激素的核心信号通路方面取得了令人兴奋的进展。现在植物激素生物学正在进入一个具有挑战性的时期，以了解这些小分子传递的信息如何转化为细胞反应。此外，我们还进入了一个需要将实验模型的信息转化为重要作物的阶段。我的研究项目是研究两种植物激素，脱落酸（ABA）和独角酯内酯（SLs）在发芽和幼苗早期生长方面的基本机制。在这里，我建议使用系统和化学生物学的前沿工具，在基础水平和生物技术应用方面以新颖的方式将这些激素与植物生长和发育网络联系起来。******项目1:ABA是一种长期研究的激素，介导各种王国的各种发育反应。在植物中，ABA在萌发和叶片水分关系中起着关键作用。在转录水平上，ABA调节着超过三分之一的植物基因组。因此，阐明由ABA控制的转录因子（TFs）对于将这种激素与其控制的许多发育过程联系起来至关重要。在其他模型系统中，在没有任何先前的生物学知识的情况下，通过监测全局基因表达来控制tf的激活是在体内分配功能的一种富有成效的策略。在先前蛋白质网络研究的基础上，我们将在拟南芥模型中使用系统方法来开发第一个细胞类型特异性ABA调节的TF网络。该方法应该适用于其他具有复杂转录输出的植物激素系统。******项目2:SLs形成了一类相对较新的激素，被寄生植物Striga属用作发芽线索，以协调其生长与宿主的生命周期。一旦作物被种植，它们的根就会释放出SLs，这种SLs会刺激Striga种子发芽，从而使寄生虫感染并吸收宿主的营养。仅在非洲，联合国就将其列为非洲大陆赤贫的主要原因。因此，了解Striga如何将SLs视为发芽线索，对于开发对抗这种杂草的农业化学策略至关重要。我们将建立一个高通量的化学遗传学筛选系统，以鉴定新的SL激动剂和拮抗剂结合SL受体。这些化学物质将使我们能够在不需要复杂的遗传学或转基因技术的情况下探测Striga复杂的SL受体系统。此外，这些探针可以作为开发ag生物技术化合物的先导物，以减少Striga的侵袭

Summary: Plant hormones are a collection of small structurally unrelated molecules that have profound effects on plant growth and development. Over the past decade, exciting advances have been made to define core-signaling pathways for many hormones. Now plant hormone biology is entering a challenging period of understanding how the information conveyed by these small molecules is turned into cellular responses. Furthermore, we are also entering a stage where information from experimental models needs to be translated to important crops. My research program investigates the fundamental mechanisms of two plant hormones, abscisic acid (ABA) and strigolactones (SLs) with respect to germination and early seedling growth. Here, I propose to use the cutting edge tools of systems and chemical biology to link these hormones to plant growth and development networks in novel ways both at a fundamental level and for biotechnological application.******Project 1: ABA is a long studied hormone that mediates an assortment of developmental responses across a variety of kingdoms. In plants, ABA is a key player in germination and leaf water relations. At a transcriptional level, ABA regulates over a third of a plant's genome. Thus, the elucidation of the transcription factors (TFs) that are controlled by ABA is critical to linking this hormone to the numerous developmental processes that it controls. In other model systems, controlled activation of TFs followed by monitoring of global gene expression has been a fruitful strategy in assigning functionality in vivo without any prior biological knowledge. Building on previous protein network studies, we will use systems approaches in the model Arabidopsis to develop the first cell type specific ABA regulated TF network. The approach should be adaptable to other plant hormone systems, which have complicated transcriptional outputs.******Project 2: SLs form a relatively new class of hormones that are used as a germination cue by parasitic plants of the Striga genera to coordinate their growth with a host's life cycle. Once crops are planted, their roots exude SLs, which act to stimulate Striga seed germination thereby allowing the parasite to infect and withdraw host nutrients. In Africa alone, the UN classifies Striga hermonthica infestations as the major cause of abject poverty on the continent. Understanding how Striga perceives SLs as a germination cue is therefore essential to developing agro-chemical strategies to combating this weed. We will establish a high throughput chemical genetics screening system to identify novel SL agonists and antagonists that bind SL receptors in Striga hermonthica. These chemicals will allow us to probe the complex SL receptor system in Striga without the need of sophisticated genetics or transgenic technologies. Furthermore, these probes can be used as leads in the development of Ag-biotech compounds to decrease Striga infestations.**