Molecular and ecological investigations into the infection process of Eurychasma dicksonii on brown algae

许多最具破坏性的农业和水产养殖病原体属于卵菌群。此外，许多卵菌严重影响自然种群的生态。在沿海海洋生态系统中，卵菌类Dicksonii被认为对褐藻种群的形成做出了贡献。它不仅是已报道的海洋病原体中最大的宿主范围-感染迄今测试的几乎所有褐藻物种，而且它也是天然褐藻种群中最普遍的真核病原体。值得注意的是，对狄克逊肠杆菌的致病性、生物学、流行病学和生态学的许多基本方面几乎一无所知。作为海洋2025核心战略计划的一部分，我们目前正在开发工具，以研究狄克逊肠杆菌疫情对藻类种群和沿海生态系统的影响。然而，许多悬而未决的生物学问题对这项工作至关重要。了解狄克逊棘球藻为什么有如此广泛的寄主范围，是什么使这种病原体如此成功，以及它使用什么致病决定因素和感染策略来感染宿主，将有助于揭示迪克森氏棘球藻流行暴发如何影响自然褐藻种群，以及这种病原体可能如何影响它们的遗传结构。本应用程序旨在更详细地解决这些问题。已确定的宿主特异性决定因素将进一步与来自世界各地的病原体的遗传和生物地理背景相关。在这项研究完成后，我们希望证明狄克逊肠杆菌正在分泌效应分子，这些分子可能被转移到宿主细胞中，并且处于多样化的选择之下。我们希望就它们在狄克逊棘球藻与宿主的生物营养相互作用中的作用以及它对自然褐藻种群的影响产生准确的假设。

Many of the most devastating agricultural and aquacultural pathogens belong to the group of oomycetes. In addition, many oomycetes seriously impact upon the ecology of natural populations. In coastal marine ecosystems, the oomycete Eurychasma dicksonii is thought to contribute to shaping populations of brown algae. It not only has the largest reported host range among marine pathogens - infecting virtually every brown algal species tested so far, but it is also the most prevalent eukaryotic pathogen in natural brown macroalgal populations. Remarkably, virtually nothing is known about many fundamental aspects of pathogenicity, biology, epidemiology, and ecology of E. dicksonii. As part of the Oceans 2025 core strategic program, we are currently developing tools to study the impact of E. dicksonii epidemics on algal populations and coastal ecosystems. However, many unresolved biological questions are of critical importance to underpin this undertaking. Understanding why E. dicksonii has such a wide host-range, what makes this pathogen so successful, and what pathogenicity determinants and infection strategies it uses to infect its hosts will shed light on how natural brown algal populations are affected by epidemic outbreaks of E. dicksonii, and how this pathogen might influence their genetic structure. This application aims to address these issues in more detail. Identified determinants of host specificity will further be correlated to the genetic and biogeographical background of the pathogen from sites around the world. At the completion of this study, we expect to demonstrate that E. dicksonii is secreting effector molecules that may be translocated into the host cells, and that are under diversifying selection. We hope to generate precise hypotheses on their role in the biotrophic interaction of E. dicksonii with its hosts, as well as its impact on natural brown algal populations.