Metabolism and regulation of ancient protective biopolymers in the moss, Physcomitrella

苔藓、立碗藓中古代保护性生物聚合物的代谢和调节

• 批准号: RGPIN-2018-04286
• 负责人: Suh, DaeYeon
• 金额: $ 2.11万
• 依托单位: University of Regina
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=666153
• 关键词: Metabolism; regulation; ancient; protective; biopolymers

The transition of plants from aquatic to terrestrial environments about 500 million years ago is one of the most important events in the evolution of life on earth. On land, early land plants encountered new challenges, which included surviving exposure to UV irradiation, desiccation and gravity. In order to cope with these challenges, early land plants developed, among other attributes, protective extracellular matrices of sporopollenin, cuticle and lignin. Sporopollenin is the main polymeric constituent of the outer walls of spore and pollen grain and the cuticle is a lipidic outer layer of aerial plant tissues. Lignin, which evolved later, is a class of phenolic polymers that lend rigidity to vascular plant tissue. Bryophytes comprising liverworts, mosses, and hornworts are the simplest and earliest-diverging lineages of land plants, and offer unique windows into the early evolution of land plants. With a complete genome sequence and other research resources, the moss Physcomitrella patens has emerged as a model bryophyte for research on plant evolution. In Physcomitrella, a target gene can efficiently be knocked out, allowing researchers to study the function of the target gene. This research program seeks to understand how the metabolic pathways for the protective materials evolved during early land plant evolution, which is one of the fundamental outstanding questions in plant science. Using multi-faceted, interdisciplinary and hypothesis-based approaches, we will determine how sporopollenin is polymerized during spore maturation and depolymerized during spore germination. We will also study the biosynthesis, metabolism and regulation of the cuticle and lignin-like phenolic compounds that provide the plant with desiccation tolerance and mechanical strength. This research will lead to novel discoveries that are applicable to other plant species, and provide new insights into how the earliest plants successfully adapted on land. Sporopollenin biosynthetic genes are good targets to generate plant male sterility for hybrid seed production and forest/crop control. Being the most robust biopolymer, sporopollenin also has unique applications in biotechnology (biodegradable polymer), medicine (oral vaccination and drug carrier) and wastewater treatment (metal sorbents). Our research may also lead to a new strategy for improving desiccation tolerance in other plants of agricultural importance. This program utilizes diverse research tools and thereby offers training opportunities in different areas of plant science ranging from molecular biology to phytochemistry. HQPs trained in multiple core areas in plant science will contribute to the advancement of science and technology in Canada.

大约5亿年前，植物从水生环境向陆地环境的转变是地球生命进化中最重要的事件之一。在陆地上，早期的陆地植物遇到了新的挑战，包括在紫外线照射、干燥和重力下生存。为了应对这些挑战，早期的陆地植物除了其他属性外，还发展出了孢粉质、角质层和木质素的保护性细胞外基质。孢粉质是孢子和花粉粒外壁的主要聚合成分，角质层是气生植物组织的脂质外层。后来进化出来的木质素是一类酚类聚合物，可以赋予维管束植物组织刚性。由地钱、苔藓和金鱼藻组成的苔藓植物是陆地植物中最简单、最早分化的谱系，为了解陆地植物的早期进化提供了独特的窗口。凭借完整的基因组序列和其他研究资源，苔藓小立碗藓已成为植物进化研究的模式苔藓植物。在立碗藓中，目标基因可以被有效地敲除，从而使研究人员能够研究目标基因的功能。该研究项目旨在了解早期陆地植物进化过程中保护材料的代谢途径是如何进化的，这是植物科学中的基本悬而未决的问题之一。使用多方面、跨学科和基于假设的方法，我们将确定孢粉质在孢子成熟过程中如何聚合以及在孢子萌发过程中如何解聚。我们还将研究角质层和类木质素酚类化合物的生物合成、代谢和调节，这些化合物为植物提供了耐干燥性和机械强度。这项研究将带来适用于其他植物物种的新发现，并为最早的植物如何成功适应陆地提供新的见解。孢粉质生物合成基因是产生植物雄性不育性以用于杂交种子生产和森林/作物控制的良好靶标。作为最坚固的生物聚合物，孢粉素在生物技术（可生物降解聚合物）、医学（口服疫苗和药物载体）和废水处理（金属吸附剂）方面也有独特的应用。我们的研究还可能带来一种提高其他具有农业重要性的植物的耐旱性的新策略。该计划利用多种研究工具，从而提供从分子生物学到植物化学等植物科学不同领域的培训机会。在植物科学多个核心领域接受培训的总部人员将为加拿大科学技术的进步做出贡献。