Host and vector manipulation following multi-infection of aphid transmitted viruses in sugar beet (Beta vulgaris)

甜菜(Beta vallgaris subsp.)、病毒黄化病(Virus Yellowes，VY)是由不同种类的蚜传病毒组成的复合体引起的，其中桃蚜是最重要的媒介。在欧洲，甜菜黄化病毒(BYV)、甜菜轻度黄化病毒(BMYV)、甜菜黄化病毒(BChV)和甜菜花叶病毒(BtMV)是甜菜黄化病毒的主要病原菌。甜菜黄化病毒(BYV)、甜菜轻度黄化病毒(BMYV)、甜菜黄化病毒(BChV)和甜菜花叶病毒(BtMV)是甜菜黄化病毒的主要病原菌。甜菜黄化病毒(BYV)、甜菜轻度黄化病毒(BMYV)、甜菜黄化病毒(BChV)和甜菜花叶病毒(BtMV)是甜菜黄化病毒病的主要病原。共侵染病毒在许多植物物种中都是已知的，可以增强至少一种病毒的复制、组织传播、媒介传播率和其他适合性成分，并影响病毒的性质，如宿主范围、细胞嗜性和媒介偏好。此外，密切相关病毒的多重感染是RNA重组的起点，启动了新的、通常更强的毒株或病毒种类的形成。由于不能期望在Beta基因库中获得自然的多病毒抗药性，并且禁止通过杀虫剂治疗减少媒介种群的传统病毒控制，迫切需要控制该疾病的替代解决方案。考虑到这一点，我们的项目旨在了解宿主共生期间的病毒相互作用，以及因多重感染而改变的媒介相互作用，这些相互作用可能分别加剧对植物的影响和增加传播。在病毒-植物水平上，我们的目标是破译假定的协同相互作用，通过转录组学鉴定所涉及的植物蛋白，并表征黄化病毒在单一感染中操纵的代谢途径--与选定的联合/多重感染相比较。在病毒感染对媒介操纵的水平上，应确定和量化联合感染对蚜虫行为以及病毒传播偏好的影响。该项目的主要成果是更好地了解了在多重感染的情况下，病理系统的三个组成部分(植物-病毒-病媒)之间的紧密相互作用，这是一种生物学现实。最终，该项目可能会确定未来安全和环境友好的控制措施的目标。

In sugar beet (Beta vulgaris subsp. vulgaris), virus yellows (VY) disease is caused by a complex of different aphid-transmitted virus species, with Myzus persicae being the most important vector. In Europe, beet yellows virus (BYV), beet mild yellowing virus (BMYV), beet chlorosis virus (BChV) and beet mosaic virus (BtMV) are the main causatives and were shown to hamper sugar beet cultivation not only in single but also in co- and multi-infection. Co-infecting viruses are known in many plant species to enhance replication, tissue spread, vector transmission rate and other fitness components of at least one of the viruses involved and influence viral properties such as host range, cellular tropism and vector preference. Furthermore, multi-infection of closely related viruses is the starting point for RNA recombination initiating the formation of new, often more virulent strains or virus species. As natural multi-virus resistance cannot be expected to be available in the Beta genepool and conventional virus control by reducing vector populations through insecticide treatment was banned, alternative solutions controlling the disease are urgently required. Having this in mind, our project aims to understand viral interactions during host co-colonization as well as vector interactions that are altered by multi-infections and might acerbate impact on plants and increase transmission, respectively. On the virus-plant level, we aim to decipher putative synergistic interactions, identify by transcriptomics plant proteins involved and characterize metabolic pathways that are manipulated by the yellowing viruses in single- compared to selected co-/multi-infections. On the level of vector manipulation by the virus infection, effects on aphid behaviour as well as virus transmission preferences in co-infections shall be identified and quantified. The major outcome of this project is a better understanding of the tight interactions between the three components of the pathosystem (plant-virus-vector) in a multi-infection context, which is a biological reality. Ultimately, this project could potentially identify targets for future control measures that will be safe and environmentally friendly.