CharKeyS: Charophyte key genome sequencing

陆地植物的起源是单系的，很可能起源于大约5亿年前一种淡水轮藻对陆地栖息地的一次成功殖民。最近的研究表明，与绿藻不同的是，陆地植物的轮藻祖先携带着使它们能够适应陆地上遇到的极端环境的基因。为了加深我们对进化的理解，并应对维持和提高粮食产量的挑战，了解哪些性状使轮藻(链藻)能够进化为陆地植物，以适应可想象到的最剧烈的生境变化之一，这是至关重要的。轮藻的一个主要原因是，到目前为止，人们很少关注轮藻具有环境弹性的特征，这是缺乏成熟的模式生物。在我们运行的DFG资助的合作项目CharMod中，我们因此建立了两个模式生物，分别来自Charophyceae和Zygnematophyceae，代表了与陆地植物关系最密切的两个纲。CharMod的目标是识别具有相对较小基因组的快速生长生物，这些生物能够在无菌条件下进行体外生命周期。在目前的CharKeyS提案中，我们要求提供资金，为这两个物种中的每个物种生成高质量的基因组组装和注释。预计通过提供这些新兴模式生物的基因组和转录组数据，该项目将帮助越来越多的科学界对导致现有轮藻祖先殖民土地的分子适应进行研究。特别是，这些数据将极大地帮助最近资助的优先方案马德兰。

Land plants are monophyletic in origin, most probably deriving from a single successful colonization of the terrestrial habitat by a freshwater charophyte alga ca. 500 million years ago. It could recently be shown that charophyte ancestors of land plants, in contrast to the green algae, carried the genetic repertoire enabling them to adapt to the environmental extremes encountered on land. To deepen our evolutionary understanding, and to meet the challenge of maintaining and improving food production, it is essential to learn which traits enabled charophyte (streptophyte) algae to evolve to land plants, adapting to one of the most drastic habitat changes conceivable.One main reason that - so far - only little attention has been paid to traits enabling environmental resilience in charophyte algae is the lack of well established model organisms. In our running DFG funded collaborative project CharMod we are thus establishing two model organisms from the Charophyceae and Zygnematophyceae, representing two of the classes most closely related to land plants. CharMod aims to identify fast growing organisms with relatively small genomes, capable to perform their life cycle in vitro under axenic conditions. In the present proposal CharKeyS we ask for funding to generate high quality genome assemblies and annotations for each of these two species.It is expected that by providing genomic and transcriptomic data for these emerging model organisms the project will help a growing scientific community to perform research on the molecular adaptations having led to the colonization of land by the ancestors of extant charophyte algae. In particular, these data will much aid the recently funded Priority Programme MAdLand.