Collaborative Research:RUI: Invasion of land: Using model charophyte Penium margaritaceum to elucidate subcellular responses to stress that were key in the evolution of land plants

合作研究：RUI：入侵土地：利用轮藻模型阐明亚细胞对胁迫的反应，这是陆地植物进化的关键

• 批准号: 1517546
• 负责人: Jocelyn Rose
• 金额: $ 26.21万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517546&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Invasion; land

The colonization of land by green algae 450 to 500 million years ago and their evolution into land plants represent important events in the natural history of the planet. These terrestrial (land) plants have caused major changes to the Earth's biochemistry and biosphere. Land plants evolved from green algae called charophytes, a small but diverse group of freshwater and terrestrial organisms. Central to the success of the charophyte colonization of land was the extracellular matrix (ECM) that surrounds their cells. This ECM is made up of a wall that covers the outside of the cell and the gel-like substances that are secreted from these organisms. This project will provide a comprehensive understanding of the formation and function of the ECM of the charophyte being tested, Penium. This organism will be grown under various environmental conditions, including water stress and extreme dryness. The ECM and its related biosynthetic processes will be studied using cutting edge technologies that were previously funded by the National Science Foundation. This research will provide insight into the mechanisms that were important to initiate survival on land by ancient charophytes, as well as mechanisms that are still used by many land plants today. This information will be used to devise models of how plants adapt to life on land and how they tolerate non-biological stresses such as drought. This project will also provide opportunities for post-doctoral training and summer undergraduate research, initiate external summer programs for local high school students, and serve as a basis for future course development.The goal of this project is to provide a comprehensive understanding of the extracellular matrix (ECM) and its biosynthesis dynamics in the model charophyte, Penium. It will examine the changes that occur in ECM processing when cells are placed under desiccation stress. The ECM and its biosynthetic machinery will be studied using molecular, biochemical, and high resolution microscopy technologies previously funded by the National Science Foundation. This will provide insight into mechanisms that were important to survival on land by ancient charophytes and continue to be used by many land plants, including those exposed to drought. Specific areas to be studied include: (A) polar cell growth in Penium, with an emphasis on pectin and cellulose production during wall expansion; (B) the secretion of ECM components involving two distinct pathways, the cell wall polysaccharides delivered to specific expansion zones along with extracellular polymeric substances extracellular (EPS) targeted to transitory secretion sites; (C) changes in cell wall architecture; and (D) EPS targeted production and delivery that are critical for tolerating abiotic stresses. The results of this project will be of significance to the fields of plant evolutionary biology, cell biology, molecular biology, and developmental biology. This project will also provide significant opportunities for outreach and student training.

450 至 5 亿年前绿藻在陆地上的殖民及其进化为陆地植物代表了地球自然历史上的重要事件。这些陆生植物给地球的生物化学和生物圈带来了重大变化。陆地植物是由称为轮藻类的绿藻进化而来的，轮藻类是一种规模虽小但多样化的淡水和陆地生物。轮藻植物在陆地上成功定居的关键是围绕其细胞的细胞外基质（ECM）。这种 ECM 由覆盖细胞外部的细胞壁和这些生物体分泌的凝胶状物质组成。该项目将全面了解正在测试的轮藻植物 Penium 的 ECM 的形成和功能。这种生物体将在各种环境条件下生长，包括水分胁迫和极端干燥。 ECM 及其相关的生物合成过程将使用先前由国家科学基金会资助的尖端技术进行研究。这项研究将深入了解古代轮藻类在陆地上生存的重要机制，以及当今许多陆地植物仍在使用的机制。这些信息将用于设计植物如何适应陆地生活以及如何耐受干旱等非生物胁迫的模型。该项目还将提供博士后培训和暑期本科生研究的机会，为当地高中生启动外部暑期项目，并作为未来课程开发的基础。该项目的目标是提供对细胞外细胞的全面了解轮藻模型中的基质（ECM）及其生物合成动力学。它将检查当细胞处于干燥压力下时 ECM 处理中发生的变化。 ECM 及其生物合成机制将使用先前由国家科学基金会资助的分子、生化和高分辨率显微镜技术进行研究。这将有助于深入了解对古代轮藻类在陆地上生存至关重要的机制，并继续被许多陆地植物（包括那些遭受干旱的植物）所利用。需要研究的具体领域包括：(A) Penium 的极性细胞生长，重点是细胞壁扩张过程中果胶和纤维素的产生； (B) ECM成分的分泌涉及两个不同的途径，细胞壁多糖与靶向短暂分泌位点的胞外聚合物质(EPS)一起递送到特定的扩展区域； (C) 细胞壁结构的变化； (D) EPS 有针对性的生产和交付，这对于耐受非生物胁迫至关重要。该项目的成果将对植物进化生物学、细胞生物学、分子生物学和发育生物学等领域具有重要意义。该项目还将为外展和学生培训提供重要机会。