Comparative analysis of cross kingdom RNA transfer in smut/plant pathosystems

胞外小泡(EVS)是一种有效的RNA传递载体，例如，介导微生物与寄主植物之间的密集通讯。我们将从两种具有不同寄主特异性的黑粉菌的角度来研究这一新的RNA运输过程。玉米黑粉病是玉米黑粉病的致病原因，是细胞内RNA运输的可靠模型。拟南芥侵染十字花科植物，包括模式植物拟南芥，这有助于从植物方面深入研究相互作用。有趣的是，梅迪斯虫已经失去了它的RNAi机制，而它仍然存在于T.thlasPeos中。通过采用比较的方法，我们将受益于两个病理系统的相对优势。因此，我们处于一个独特的位置，可以详细分析来自相关真菌的EV传递的RNA，以确定共同的主题。差异将使人们对宿主专业化和RNAi机制在感染过程中的使用有更深入的了解。我们将检查真菌EV的sRNA和mRNAs，以确定它们的相对生物学意义。为了达到我们的目标，我们将(I)产生一份详细的SmUT EVS的RNA和蛋白质含量的清单，(Ii)研究EV介导的RNA转移的功能相关性以及(Iii)研究EVS中RNAs选择和装载的潜在机制。这一战略将澄清RNA如何促进Smut与宿主之间的通信的问题。对相关黑穗病与本研究单位研究的不同病原菌和共生体的比较分析将揭示高度保守的核心成分以及生活方式或寄主特有的适应。所获得的洞察力将指导通过RNA介导的防御策略来针对病原体的新方法。

Extracellular vesicles (EVs) are potent vehicles for RNA delivery mediating for example the intensive communication between microbes and their host plants. We will study this novel RNA trafficking process from the perspective of two smut fungi with distinct host specificities. Ustilago maydis causes smut disease in corn and serves as an established and amenable model for intracellular RNA transport. Thecaphora thlaspeos infects Brassicaceae species including the model plant Arabidopsis thaliana, which facilitates in-depth examination of the interaction from the plant side. Interestingly, U. maydis has lost its RNAi machinery, while it is still present in T. thlaspeos. By following a comparative approach, we will benefit from the relative strengths of both pathosystems. Thus, we are in a unique position for a detailed analysis of EV-delivered RNA from related fungi to identify common themes. Differences will give insights into host specialisation and the employment of the RNAi machinery in the infection process. We will examine both the sRNA and mRNA cargos of fungal EVs to determine their relative biological significance. In order to reach our goals, we will (i) generate a detailed inventory of the RNA and protein content of smut EVs, (ii) study the functional relevance of the EV-mediated RNA transfer as well as (iii) investigate the underlying mechanism of selection and loading of RNAs in EVs. This strategy will clarify the question of how RNA contributes to smut-host communication. The comparative analysis of related smuts with the diverse pathogens and symbionts studied in our research unit will uncover both highly conserved core components as well as life-style or host-specific adaptations. Gained insights will guide novel approaches to target pathogens by RNA-mediated defence strategies.