OMICs based analysis of cytochalasans in fungal-bacteria-insect interactions

该提案的主要目标是使用基于OMIC的方法（代谢组学，基因组学，转录组学）研究真菌-细菌-昆虫相互作用中细胞松弛素的结构多样性和功能。该建议基于三个具体的工作假设：1）真菌中细胞松弛素本身和协同次级代谢产物的产生是由细菌信号和昆虫衍生组分触发的，并且使病原体能够在昆虫上茁壮成长; 2）功能化的细胞松弛素可以用于鉴定非肌动蛋白样细胞/细菌靶标; 3）可以利用细胞松弛素生物合成的天然混杂性来创建用于生物测试的底物文库。这三个假设将在四个互补和定义的工作包中进行研究，其目的是真菌-细菌和真菌-昆虫相互作用测定的详细代谢组学和转录组学分析（WP 1），天然细胞松弛素组合的协同活性测定（WP 2），双功能细胞松弛素在鉴定细菌靶标中的应用（WP 3），以及通过利用编码细胞松弛素的生物合成途径（WP 4）的天然混杂性来扩增细胞松弛素文库。在资助期内，该项目旨在建立一个更通用和标准化的实验装置，用于在代谢组学和转录组学水平上研究跨王国的相互作用，这将长期作为在更广泛的背景下分析重要的真菌-细菌相互作用的工具。该项目的结果将提供详细的见解昆虫病原真菌或寄生真菌应用细胞松弛素杀死细菌防御共生体和昆虫宿主的机制。我们的总体研究结果将有助于合理开发新型抗菌细胞松弛素，确定其细菌靶标，并为细胞松弛素相关BGC的系统发育历史和调控提供有价值的见解。

The main objective of this proposal is to study the structural diversity and functions of cytochalasans in fungus-bacteria-insect interactions using an OMICs-based approach (metabolomics, genomics, transcriptomics). The proposal is based on three specific workinghypotheses: 1) The production of cytochalasans per se and synergizing secondary metabolites in fungi is triggered by bacterial signals and insect-derived components and enables the pathogen to thrive on insects; 2) functionalized cytochalasans can be applied to identify non-actin like cellular/bacterial targets; 3) natural promiscuity of cytochalasan biosynthesis can be exploited to create a substrate library for biological testing. These three hypotheses will be investigated in four complementary and defined work packages, which aim for the detailed metabolomic and transcriptomic analysis of fungus-bacteria and fungus-insect interactions assays (WP1), thedetermination of synergistic activities of natural cytochalasans combinations (WP2), the application of bifunctional cytochalasans to identify bacterial targets (Wp3), and the expansion of the cytochalasan library by exploiting the natural promiscuity of cytochalasan-encoding biosynthetic pathways (WP4). Within the funding period, this project aims to establish a more general and standardized experimental set-up for studying cross-kingdom interactions on a metabolomic and transcriptomic level, which will serve in long-term as tool to analyse important fungus-bacteria interactions in a broader context. Results of this project will provide detailed insights into the mechanisms by which entomopathogenic or parasitic fungi apply cytochalasans to kill bacterial defensive symbionts and the insect host. Our overall findings will help to rationally develop novel antimicrobial cytochalasans, identify their bacterial targets and to provide valuable insights into the phylogenetic history and regulation of cytochalasan-related BGCs.