Klebsome: Klebsormidiophyceaen genome diversity and adaptations to terrestrial environments

Klebsome：Klebsormidiophyceaen基因组多样性和对陆地环境的适应

• 批准号: 509535047
• 负责人: Professor Dr. Jan de Vries
• 金额: --
• 依托单位: Abteilung Angewandte Bioinformatik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/509535047?language=en
• 关键词: Klebsome; Klebsormidiophyceaen; genome; diversity; adaptations

Our planet is covered by land plants. All of this biodiversity evolved from algae in a singular event that set the conquest of land by plants in motion, forever changing the face of our planet. Major phylogenomic efforts have established a robust framework for understanding this singularity: The green lineage is deeply split into the chlorophytes and the streptophytes. The streptophytes encompass the land plants and the streptophyte algae. Among these streptophyte algae, the Zygnematophyceae followed by the Coleochaetophyceae were pinpointed as closest algal relatives to land plants. However, the arguably most resilient land colonizers among streptophyte algae are the Klebsormidiophyceae, which shared a common ancestor with land plants more than 700 million years ago. I hypothesize that, despite their phylogenetic distance, klebsormidiophyceaen resilience is built on a genetic chassis that is conserved between land plants and their algal relatives—across 700 million years of streptophyte evolution. Klebsormidium nitens was the first streptophyte alga to have its nuclear genome sequenced. It was found to bear a surprising number of land plant heritage genes—but at the time there were no other genomes of streptophyte algae to contextualize these results. Now, we have genome coverage of almost all major groups of streptophyte algae. Yet, Klebsormidium still stands out regarding the contiguity of pathways and signaling cascades classically ascribed to land plants—especially in light of its more than 700 million years divergence from land plants. The ubiquity of Klebsormidiophyceae in terrestrial environments is likely written in their genes—potentially those shared with land plants. In this project, we will build upon the experience my team and I have garnered in functional genomics on diverse streptophyte algae. We will test the hypothesis that a robust genetic backbone for response pathways to environmental factors, such as the phenylpropanoid biosynthesis genes, is shared by all Klebsormidiophyceae—and a potential synapomorphy of Klebsormidiophyceae and Phragmoplastophyta. We will: (1) establish a phylogenomic framework for Klebsormidiophyceae by performing the first systematic phylogenomic survey of the class Klebsormidiophyceae; (2) sequence four genomes of Klebsormidiophyceae to facilitate robust inference of trait evolution; (3) generate global gene expression data of diverse Klebsormidiophyceae challenged by terrestrial stressors to establish a fine-grained response profile that is common to all four Klebsormidiophyceae; (4) compare and redefine synapomorphies using the functional genomic data. By integrating the robust genomic backbone with gene expression profiles and analyses of important candidate gene families, we will define the stress responsive coding capacity salient to (a) the clade Klebsormidiophyceae and (b), contextualized with land plant data, reconstruct their common ancestor that existed more than 700 million years ago.

我们的星球被陆地植物覆盖。所有这些生物多样性都是由藻类进化而来的，这一单一事件推动了植物对土地的征服，永远地改变了我们星球的面貌。主要的系统基因组学研究已经为理解这一奇异性建立了一个强有力的框架：绿色谱系被深深分为绿藻和链藻。链生植物包括陆生植物和链生藻类。在这些链藻中，最接近陆生植物的是Zygnematophyceae，其次是Coleochaetophyceae。然而，在链藻中最具弹性的陆地殖民者是Klebsormidiophyceae，它们在7亿多年前与陆地植物有共同的祖先。我推测，尽管它们的系统发育距离遥远，但klebsormidiophyceen的恢复能力是建立在陆地植物和它们的藻类亲戚之间保守的遗传基础上的——在7亿年的链藻进化中。克雷伯索菌是第一个对其核基因组进行测序的链藻。人们发现它携带了数量惊人的陆地植物遗传基因，但当时没有其他的链藻基因组来支持这些结果。现在，我们有了几乎所有主要链藻群的基因组覆盖。然而，klebsordium在传统上归因于陆生植物的途径和信号级联的连续性方面仍然突出，特别是考虑到它与陆生植物的差异超过7亿年。Klebsormidiophyceae在陆地环境中的普遍存在可能是由它们的基因决定的——这些基因可能与陆地植物共享。在这个项目中，我们将以我和我的团队在各种链藻的功能基因组学方面积累的经验为基础。我们将验证一个假设，即所有Klebsormidiophyceae和phragmoplasophyta都有一个强大的遗传主干，用于对环境因素的反应途径，如苯丙类生物合成基因，以及Klebsormidiophyceae和phragmoplasophyta的潜在突触形态。我们将：(1)通过对Klebsormidiophyceae类进行首次系统的系统基因组调查，建立Klebsormidiophyceae的系统基因组框架；(2)对Klebsormidiophyceae的4个基因组进行测序，为性状进化提供可靠的推断；(3)生成各种Klebsormidiophyceae在陆地胁迫下的全局基因表达数据，建立四种Klebsormidiophyceae共同的细粒响应谱；(4)利用功能基因组数据对突触形态进行比较和重新定义。通过整合强大的基因组骨架与基因表达谱和重要候选基因家族的分析，我们将定义(a) Klebsormidiophyceae进化支的应激响应编码能力；(b)与陆地植物数据相结合，重建它们存在于7亿多年前的共同祖先。