Fungal development of Verticillium resting structures and plant infection

土传植物病原性大丽轮枝菌真菌形成黑化微菌核，可以在土壤中休息和存活十多年。这种休眠真菌生存结构的发育通常与特定次级代谢物的生物合成有关。微菌核的萌发是由适当的宿主植物的根分泌物触发的，这导致真菌菌丝朝向植物根的定向生长。大丽轮枝菌定殖于根皮层并侵入血管系统。分生孢子在木质部中开始，以利用树液流将真菌分布在植物内。真菌在宿主体内的定殖可导致疾病症状，如褪绿、坏死、生长受阻或枯萎。植物病原性大丽轮枝菌感染多达400种植物，包括重要的农业作物，并在全球范围内造成日益严重的经济损失。该研究项目旨在阐明Verticillium Vta-Som 1-Velvet与未折叠蛋白反应Hac 1转录因子之间的复杂相互作用。这些调控因子协调连续和相互关联的遗传网络，用于大丽轮枝菌通过根部发育和感染到植物木质部系统中。这些网络，我们已经确定在第一个资助期，控制微菌核的形成，作为土壤中的休息和生存结构。它们发芽，真菌定殖植物，最后在季节结束时再次开始微菌核形成。详细的分子理解的控制机制，减少V. dahliae微菌核形成在宿主植物或土壤中的真菌定殖将是非常有帮助的。VTA-SOM 1-VELVET网络响应外部生物（例如根际微生物组，植物）和非生物环境以及内部信号传导途径。VTA-SOM 1-VELVET网络控制和调整基因表达，以适应生长，防御，发育或分泌中的适当真菌应答。我们将分析（i）不同的大丽轮枝菌VTA-SOM 1-VELVET基因网络如何协调和连接，以及哪些基因直接受特定转录因子控制。我们将（ii）确定翻译后修饰，包括磷酸化和泛素化/去泛素化，并研究VTA-SOM 1-VELVET遗传网络的转录因子的蛋白质稳定性控制机制及其对真菌发育和毒力的影响。我们将使用遗传学，细胞生物学，蛋白质组学，代谢组学以及致病性实验的组合，包括例如缺失菌株，GFP-下拉，ChIPSeq，根和植物感染的产生和研究。我们的目标是详细了解生长季节结束时微菌核形成所需的分子控制步骤，土壤中萌发微菌核产生的菌丝，真菌根系附着和植物宿主的定殖以及疾病症状诱导。

Soil-borne plant-pathogenic Verticillium dahliae fungi form melanised microsclerotia, which can rest and survive for more than a decade in the soil. Development of such dormant fungal survival structures is often linked to the biosynthesis of specific secondary metabolites. Germination of microsclerotia is triggered by root exudates of appropriate host plants, which results in directed fungal hyphal growth towards plant roots. V. dahliae colonises the root cortex and invades the vascular system. Conidiation is started in the xylem to use the sap stream for distribution of the fungus within the plant. Fungal colonisation within the host can result in disease symptoms, such as chlorosis, necrosis, stunted growth or wilting. Plant-pathogenic V. dahliae infects up to 400 plants including agriculturally important crops and causes increasing economical damage worldwide. This research project aims to characterise the complex interplay between Verticillium Vta-Som1-Velvet and unfolded protein response Hac1 transcription factors. These regulators orchestrate sequential and interconnected genetic networks for development and infection of V. dahliae through the roots into the plant xylem system. These networks, which we have identified in the first funding period, control the formation of microsclerotia as resting and survival structures in the soil. They germinate, the fungus colonises the plant and finally microsclerotia formation is initiated again at the end of the season. A detailed molecular understanding of control mechanisms, which reduce V. dahliae microsclerotia formation during fungal colonisation of host plants or in soil would be very helpful. VTA-SOM1-VELVET networks respond to the external biotic (e.g. microbiomes in rhizosphere, plant) and abiotic environment as well as to internal signalling pathways. The VTA-SOM1-VELVET networks control and adapt gene expression for the appropriate fungal reply in growth, defense, development or secretion. We will analyse (i) how the different V. dahliae VTA-SOM1-VELVET gene networks are coordinated and connected and which genes are directly controlled by specific transcription factors. We will (ii) determine posttranslational modifications including phosphorylation and ubiquitination/deubiquitination and examine protein stability control mechanisms of transcription factors of the VTA-SOM1-VELVET genetic networks and their impact on fungal development and virulence. We will use a combination of genetic, cell biological, proteomic, metabolomic as well as pathogenicity experiments including for example the generation and investigation of deletion strains, GFP-pulldown, ChIPSeq, root and plant infection. Our goal is the detailed understanding of molecular control steps required for microsclerotia formation at the end of the growing season, for the hyphae derived from germinating microsclerotia in the soil, to fungal root attachment and colonisation of the plant host and disease symptom induction.