Identification, functional characterization and evolution of enzymes involved in secondary metabolism in the moss Physcomitrella patens

苔藓小立碗藓次生代谢酶的鉴定、功能表征和进化

• 批准号: 262038-2013
• 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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=547962
• 关键词: Identification; functional; characterization; evolution; enzymes

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. Once on land, early land plants faced numerous new challenges including desiccation, UV irradiation, and gravity. In order to cope with these challenges, early land plants developed, among others, extracellular matrices of sporopollenin, cutin and lignin. This research program seeks to learn more about how the biosynthetic pathways for these protective compounds evolved during early land plant evolution. 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, the moss Physcomitrella patens is rapidly emerging as a model bryophyte for research on plant evolution. In Physcomitrella patens, a target gene can efficiently be knocked out, allowing researchers to study function of the target gene. Our research has been focused on the biosynthesis of sporopollenin, a biopolymer found in spore and pollen walls, and on the evolution of plant type III polyketide synthases (PKS) that collectively produce a variety of secondary metabolites with different physiological roles. Using multi-faceted and interdisciplinary approaches, we will determine how ancient type III PKSs contributed to the early evolution of land plants, and will also elucidate the later stages of sporopollenin biosyntheses. One of the fundamental questions remain to be answered is how plants make cell walls. Our research should help answer this question. 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 and medicine. Knowledge gained in this research on the biosynthetic pathways of sporopollenin should be useful in manipulating sporopollenin biosynthesis for our benefit.

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。一旦登陆陆地，早期的陆地植物就面临着许多新的挑战，包括干燥、紫外线照射和重力。为了应对这些挑战，早期的陆地植物发育出了孢粉质、角质和木质素等细胞外基质。该研究项目旨在更多地了解这些保护性化合物的生物合成途径在早期陆地植物进化过程中是如何进化的。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，苔藓小立碗藓（Physcomitrella patens）正迅速成为植物进化研究的苔藓植物模型。在小立碗藓中，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。我们的研究重点是孢粉质（一种存在于孢子和花粉壁中的生物聚合物）的生物合成，以及植物 III 型聚酮合酶 (PKS) 的进化，这些酶共同产生多种具有不同生理作用的次生代谢产物。利用多方面和跨学科的方法，我们将确定古代 III 型 PKS 如何促进陆地植物的早期进化，并将阐明孢粉素生物合成的后期阶段。有待回答的基本问题之一是植物如何制造细胞壁。我们的研究应该有助于回答这个问题。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，孢粉素在生物技术和医学方面也有独特的应用。在这项关于孢粉素生物合成途径的研究中获得的知识应该有助于操纵孢粉素生物合成，以造福于我们。