Regulatory Systems controlling Plant Cell Axis formation, Stem Cell Specification and Plant Pathogen Defense

控制植物细胞轴形成、干细胞规格和植物病原体防御的调控系统

• 批准号: RGPIN-2020-06508
• 负责人: Berleth, Thomas
• 金额: $ 2.04万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746515
• 关键词: Regulatory; Systems; controlling; Plant; Cell

Plant architecture is anchored in a polar shoot-root axis. This axis becomes extensively branched above and below ground through the reiterative generation of new organs. Despite their amazing morphological diversity, higher vascular plants share this basic architecture and the molecular mechanisms underlying the formation of a polar axis in the early plant embryo as well as many of the mechanism operating in the terminal stem cell populations, called apical meristems, as they generate new organs and allocate new stem cell niches (meristems) for continued growth. Plants are also well known for their impressive ability to generate new shoot-root axes from disorganized tissue or even single cells in a process called regeneration, which is of utmost importance for plant breeding and biotechnology. This proposal is built on early findings, which linked auxin perception and auxin transport to the embryonic formation of a body axis, the positioning of lateral organs and leave vascular patterns and the de novo generation of new stem cell niches for shoot formation in plant tissue culture. Starting from Arabidopsis embryo mutants, auxin transport interference and visualization experiments, and based on this, the isolation of the first functional Auxin Response Factor (ARF), we made contributions to the understanding of auxin driven patterning processes in various organs. More recently, we have complemented those contributions by supplying cohorts of ARF target genes, among them genes within the auxin singling network as well as genes in the specification of auxin flow paths. Strikingly, these analytical entries have led to the discovery of a versatile genetic tool, with which we can improve the de novo establishment of stem cell niches, most dramatically in the formation of shoots during plant tissue regeneration, using a modified ARF gene, MP?, as a genetic switch. At this point, three obvious target areas need to urgently be addressed. (1) The shoot promoting activity of MP? needs to better understood, optimized and applied to more plant species. (2) The molecular reasons why one ARF protein, MP, has properties, not found in other ARFs, needs to be determined, (3) the signaling pathway through which MP controls patterning processes during regeneration and other processes needs to be further elucidated. This will involve the conversion of already identified target genes, regulated by MP, into visualization tools as well as the use and development of other novel visualization markers in hormone signal transduction. Those will not only be limited to patterning processes, but in the context of other collaborative efforts, will also include hormone markers in pathogen responses.

植物的结构固定在极枝-根轴上。这条轴线通过反复产生新的器官，在地上和地下广泛地分支。尽管高等维管植物具有惊人的形态多样性，但它们共享这种基本结构和早期植物胚胎中极轴形成的分子机制，以及在末端干细胞群体（称为顶分生组织）中运作的许多机制，因为它们产生新的器官并分配新的干细胞龛（分生组织）以继续生长。植物还以其令人印象深刻的能力而闻名，即从无序的组织甚至单个细胞中产生新的茎根轴，这一过程被称为再生，这对植物育种和生物技术至关重要。这一建议是建立在早期发现的基础上的，这些发现将生长素感知和生长素运输与植物组织培养中体轴的胚胎形成、侧壁器官和叶片维管模式的定位以及用于芽形成的新干细胞壁龛的新生联系起来。从拟南芥胚突变体、生长素转运干扰和可视化实验出发，在此基础上分离出首个功能性生长素反应因子（auxin Response Factor， ARF），为了解生长素驱动的各器官模式化过程做出了贡献。最近，我们通过提供ARF靶基因的队列来补充这些贡献，其中包括生长素单链网络中的基因以及生长素流动路径中的基因。引人注目的是，这些分析条目导致了一种多功能遗传工具的发现，通过这种工具，我们可以改善干细胞生态位的从头建立，最显著的是在植物组织再生过程中，使用修饰的ARF基因MP？，作为一个基因开关。在这一点上，迫切需要解决三个明显的目标领域。(1) MP？需要更好地理解、优化和应用于更多的植物物种。(2)需要确定一种ARF蛋白MP具有其他ARF所没有的特性的分子原因；(3)MP在再生和其他过程中控制模式过程的信号通路需要进一步阐明。这将包括将已经确定的靶基因转化为可视化工具，由MP调节，以及在激素信号转导中使用和开发其他新的可视化标记。这些将不仅限于模式过程，而且在其他合作努力的背景下，还将包括病原体反应中的激素标记。