Genetic Basis of Coleopteran Vectorial Capacity for Bean pod mottle virus Transmission

为什么有些食叶节肢动物会传播植物病原体，而另一些则不会？此外，为什么在一个病媒物种中通常只有一小部分个体精通传播特定病原体？相当数量的鞘翅目甲虫传播病毒，对经济上重要的蔬菜和作物造成疾病。然而，甲虫种类内部和不同种类之间在藏匿和传播病原体的能力方面的差异程度是显著的（即它们的媒介能力）。病媒的基因组成无疑对其对病原体感染和传播的易感性起着重要作用，但影响病媒能力的特定基因的表征却被证明是难以捉摸的。该研究的长期目标是了解昆虫传播病原体的遗传相互作用和机制。识别破坏媒介介导的病原体传播的基因将为疾病控制带来新的和有希望的途径。拟议的研究将利用大豆病理系统的独特属性，该系统由三种甲虫组成，它们在传播北美流行的大豆病毒——豆荚斑驳病毒（BPMV）的能力方面表现出个体和物种水平的差异。我之前的研究强烈表明，BPMV传播能力的遗传关键在于甲虫自身的反刍物，这些反刍物在进食时沉积在叶片损伤部位。考虑到昆虫效应基因在编码改变植物防御的蛋白质中的作用，我假设甲虫反刍中分泌的效应基因的补体也影响了寄主植物对虫媒病原体入侵的敏感性。为此，本研究将整合甲虫反流转录组与载体能力和基因组变异性数据的比较，以确定候选效应物，然后测试它们对载体能力的影响。目的1。表征效应基因反流组成的种间和种内差异。目标2。开发基于rnai的工具，从功能上表征目标1中确定的候选效应物的作用。目标3。确定自然种群中BPMV传播率和候选基因序列多态性的变异程度。我希望能够识别并从功能上暗示导致甲虫物种内部和物种之间BPMV载体能力差异的基因子集。此外，拟议的工作将导致更好地理解驱动昆虫媒介疾病传播的遗传、进化和环境因素。

Why do some leaffeeding arthropods transmit plant pathogens while others do not? Moreover, why typically are only a small minority of individuals within a vector species proficient at transmitting a particular pathogen? A considerable number of coleopteran beetles transmit viruses that cause disease to economically important vegetables and crops. However, the degree of variation within and among beetle species in their ability to harbor and transmit pathogens is remarkable (i.e. their vector competence). The genetic makeup of the vector undoubtedly contributes significantly to its susceptibility to pathogen infection and transmission, yet characterization of specific genes that influence vector competence has proven elusive. The longterm goal of the proposed research is to understand the genetic interactions and mechanisms of pathogen transmission by insects. Identifying genes that disrupt vector-mediated pathogen transmission will lead to novel and promising avenues for disease control. The proposed research will harness the unique attributes of a soybean pathosystem, consisting of three beetle species that exhibit individual and species level variation in their ability to vector a soybean virus that is prevalent in North America, Bean pod mottle virus (BPMV). My previous research strongly suggested that the genetic key' to BPMV transmission capability lies in the beetle's own regurgitant, which is deposited at leaf wounding sites during feeding. Given the role of insect effector genes in encoding proteins that alter plant defenses, I hypothesized that the complement of effectors secreted in the beetle's regurgitant also impacts host plant susceptibility to insectborne pathogen invasion. To explore this, the proposed research will integrate comparisons of beetle regurgitant transcriptomes and data on vector competence and genomic variability to identify, and then test candidate effectors for their influence on vector competence. Objective 1. Characterize interspecific and intraspecific differences in the regurgitant composition of effector genes. Objective 2. Develop RNAibased tools to functionally characterize the role of candidate effectors identified in Objective 1. Objective 3. Determine the extent of variation in BPMV transmission rates and candidate gene sequence polymorphism in natural populations.I expect to identify and functionally implicate a subset of genes that contribute to the differences in BPMV vectorial capacity within and among beetle species. Further, the proposed work will lead to a better understanding of the genetic, evolutionary and environmental factors that drive insect-vectored disease transmission.