Dissecting brassinosteroid signaling mediated regulation of root growth angle in wheat

剖析油菜素类固醇信号介导的小麦根生长角调节

• 批准号: 2746359
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2746359
• 关键词: Dissecting; brassinosteroid; signaling; mediated; regulation

RGA of different root-types (primary, seminal and crown) are often distinct to limit competition and are referred to as gravitropic setpoint angle (GSA). The vertical GSA of primary roots is maintained by the positive gravitropic mechanism, while non-vertical GSA in other root-types is determined by competing gravitropic and anti-gravitropic offset (AGO) mechanisms. Although past research in the model plant Arabidopsis unraveled gravitropic mechanisms, understanding of AGO mechanisms remains limited as crucial root-types (seminal and crown) do not exist in Arabidopsis. Moreover, these mechanisms remain largely unexplored in crops due to limited genetic resources. Wheat, an important crop for the UK and world, represents an ideal system for studying RGA as all root-types are easily distinguiishable and have available genetic and genomic resources. Recently, we screened various wheat phytohormone signaling mutants (auxin, ethylene, brassinosteroid and bibberellin) for RGA and observed that BR signaling mutants (prominently for tabri1) show significantly steeper seminal and crown roots compared to wildtype.Aim:In this project, we will determine the molecular mechanisms by which brassinosteroids control RGA in wheat.Work Plan:Do other Brassinosteroid pathway genes regulate RGA? (Year1) tabri1 (A-homeologue) showed >30% steeper seminal and crown RGA than the wildtype. We will phenotype remaining single tabri1 mutants (of B- and D-homeologues) and their combinatorial double and triple mutants and assess if the observed tabri1 pheotype is specific to A-homeolgoue or enhanced by stacking mutations in other TaBRI1 homeologues. Additionally, we will screen other available brassinosteroid signaling, biosynthetic and receptor mutants for RGA phenotype using vertical and 90 gravistmulus.Where does TaBR1-dependant RGA regulation takes place? (Year1-2)We will investigate where TaBRI1 is made in the wheat root and functions to control RGA by tagging the BRI1 protein with green fluorescent protein (GFP), then putting this transgene into tabri1 plants to test if it can rescue the mutant and reveal its location of expression.Explore the genetic diversity of BR signaling and RGA in Watkins collection (Year3)We are currently screening >800 lines from a wheat population for RGA phenotype. Using bioinformatics pipeline, we will investigate how much natural variation of RGA is explained by the polymorphism within the TaBR1. This analyss will help link the ancestory, habitat and environmental conditions from which these lines were collected and generate further testable hypothesis.What downstream components TaBR1 regulate to control RGA? (Year3-4)Extract RNA from root samples of WT and single or higher order Tabri1 mutants growing under vertical and gravistimulus conditions and perform RNAseq analysis to determine key differentially expressed genes and their enriched processes involved during BRI1 mediated RGA control. What is the relevane of TaBR1 mediated RGA? (Year4)Nutrient, water and heat stresses are known to influence RGA to optimise capture of soil resources. We will perform growth-room, glasshouse and field experiments on mutants and WT under control and stress coditions and assess the RGA, root and shoot biomass and grain yield. Output: Improved understanding of molecular mechanisms controlling RGA will guide selection of alleles that can be exploited through DFW breeders toolkit.

不同根类型的RGA（初级，精确和冠状）通常不同于限制竞争，被称为Gravitropic设定点角（GSA）。主要根部的垂直GSA由阳性重力机理维持，而其他根类型中的非垂直GSA由竞争的重力和抗极力偏移（AGO）机制确定。尽管模型植物拟南芥中的过去研究揭示了重力机制，但对AGO机制的理解仍然有限，因为拟南芥中不存在关键的根类型（精液和牙冠）。此外，由于遗传资源有限，这些机制在农作物中基本上仍未探索。小麦是英国和世界的重要农作物，是研究RGA的理想系统，因为所有根类型易于区分，并且具有可用的遗传和基因组资源。 Recently, we screened various wheat phytohormone signaling mutants (auxin, ethylene, brassinosteroid and bibberellin) for RGA and observed that BR signaling mutants (prominently for tabri1) show significantly steeper seminal and crown roots compared to wildtype.Aim:In this project, we will determine the molecular mechanisms by which brassinosteroids control RGA in wheat.Work Plan:Do other黄铜素途径基因调节RGA？ （Year1）Tabri1（A-Homeologue）比WildType显示出更陡峭的精液和冠状RGA。我们将剩余的单个tabri1突变体（b-和d-homeologues的）及其组合双重突变体和三重突变体，并评估观察到的tabri1 pheotype是否特定于a-homeolgoue或通过在其他tabri1同源物中堆叠突变而增强。此外，我们将使用垂直和90 GRAVERTMULUS筛选其他可用的黄铜固醇信号传导，生物合成和受体突变体，用于RGA表型。 (Year1-2)We will investigate where TaBRI1 is made in the wheat root and functions to control RGA by tagging the BRI1 protein with green fluorescent protein (GFP), then putting this transgene into tabri1 plants to test if it can rescue the mutant and reveal its location of expression.Explore the genetic diversity of BR signaling and RGA in Watkins collection (Year3)We are currently screening >800 lines from a wheat population for RGA表型。使用生物信息学管道，我们将研究TABR1中的多态性来解释RGA的自然变化。该分析将有助于将收集这些线的祖先，栖息地和环境条件联系起来，并产生进一步的可检验假设。哪种下游组件tabr1调节了控制RGA？ （3-4）从WT的根样本中提取RNA以及在垂直和急性条件下生长的单个或更高阶的TABRI1突变体，并进行RNASEQ分析，以确定在BRI1介导的RGA控制过程中及其在BRI1中涉及的关键差异表达基因及其富集过程。 TABR1介导的RGA的相关性是什么？ （4年）已知养分，水和热应力会影响RGA以优化土壤资源的捕获。我们将对在控制和压力代码下的突变体和WT进行生长室，温室和现场实验，并评估RGA，根和射击生物量和谷物产量。输出：对控制RGA的分子机制的了解得以提高，将指导可以通过DFW育种者工具包利用的等位基因的选择。