Towards understanding the diversity, evolutionary origins, and host spectrum of the overlooked oomycete genus Lagena

了解被忽视的卵菌属 Lagena 的多样性、进化起源和宿主谱

• 批准号: 523072614
• 负责人: Professor Dr. Marco Thines
• 金额: --
• 依托单位: Institut für Ökologie, Evolution und Diversität
• 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/523072614?language=en
• 关键词: Towards; understanding; diversity; evolutionary; origins

The genus Lagena, long thought to contain just a single species, has recently been revealed by environmental sequencing to encompass much more diversity. Gaining insights into the diversity of the group, the hosts they parasitise and the genomic features underlying pathogenicity is crucial for understanding the evolution of pythiaceeous oomycetes and the acquisition of obligate biotrophy in this group. In our previous work we could already show that the holocarpic genus Lagena not only contains parasites of plants, but also parasitoids of diatoms. It is the aim of this project to explore the diversity and evolution of Lagena and Lagena-like species still placed in other genera further, testing the hypotheses that 1) Lagena species have diversified in diatom hosts and the parasites of diatoms assigned to Lagenidium belong to Lagena instead, 2) Lagena is a widespread but overlooked root parasite, and there are lineages specialised to certain host groups, 3) There are hosts other than diatoms and angiosperms infected by the genus Lagena, e.g. filamentous cyanobacteria and oomycetes. 4) Holocarpic spore production in Lagena is a derived state, resulting from the reduction of a larger vegetative mycelium into a holocarpic thallus. 5) There are genomic features that correlate with the hosts infected and physiology (obligate vs. facultative biotrophy). The testing of these hypotheses will yield fundamental insights into an apparently widespread and diverse, yet mostly overlooked group of small holocarpic oomycetes closely related to Pythium. Overall, the knowledge gained with respect to the phylogeny, pathogenic versatility, genomic features, and evolutionary processes of these little-studied parasites will be a vital step towards understanding the evolution of pythiacaeous oomycetes. It will also constitute the basis for future studies, e.g. into the reduction of mycelia to holocarpic thalli and the parallel evolution of obligate biotrophy in different oomycete groups.

Lagena属，长期以来被认为只包含一个物种，最近通过环境测序发现包含更多的多样性。深入了解该群体的多样性、它们寄生的宿主以及致病性背后的基因组特征对于了解腐霉卵菌的进化和该群体中专性生物营养的获得至关重要。在我们以前的工作中，我们已经可以表明，全果的Lagena属不仅含有植物的寄生物，而且还含有硅藻的寄生物。本项目的目的是进一步探索Lagena和Lagena样物种的多样性和进化，进一步测试以下假设：1）Lagena物种在硅藻宿主中具有多样性，而分配给Lagenidium的硅藻的寄生虫属于Lagena，2）Lagena是一种广泛但被忽视的根寄生虫，并且存在专门针对某些宿主群体的谱系，（3）除硅藻和被子植物外，还有丝状蓝藻和卵菌等宿主感染Lagena属。4)在Lagena中，全果孢子的产生是一种衍生状态，是由较大的营养菌丝体退化成全果的叶状体而产生的。5)存在与被感染的宿主和生理学（专性与兼性生物营养）相关的基因组特征。这些假设的测试将产生一个明显的广泛和多样的，但大多数被忽视的小全果卵菌群密切相关的腐霉的基本见解。总的来说，获得的知识，这些很少研究的寄生虫的生殖，致病性的多功能性，基因组特征和进化过程将是一个重要的一步了解pythiacaeous卵菌的进化。这也将构成未来研究的基础，例如，到减少菌丝体全果性的菌体和专性生物营养在不同的卵菌群的平行进化。