How Nutritional Interactions in Multi-Partner Symbioses are Structured

许多昆虫，包括重要的农业和医疗害虫，携带共生细菌，为它们的昆虫宿主提供必需的营养，但在伙伴之间转移的营养成分和数量在很大程度上是未知的。该项目将研究以植物木质部汁液为食的昆虫的昆虫-细菌营养交换。利用基因组学和代谢模型的最新进展，研究人员将量化昆虫和细菌合成关键营养物质的能力，然后将这些结果以代谢模型的形式整合起来，描述每种营养物质在合作伙伴之间转移的数量。这些模型可以检验两个基本预测：一个伙伴产生的过量营养物质被其他伙伴所需要，从而实现昆虫在木质部汁液中生存所需的营养效率；昆虫从它们的细菌伙伴那里获得的营养成分是由整个代谢网络决定的，而不仅仅是细菌的基因含量。本研究对昆虫和细菌之间营养相互作用的综合分子理解将为新的害虫防治策略确定特定的靶点，这些害虫以木质部为食，传播影响柑橘、葡萄、咖啡和其他作物的植物病原体。该项目将为博士后研究员、研究生和本科生提供最先进的基因组学和建模方法方面的培训。为了解决序列分析和生物信息学研究基础设施与教育资源之间日益明显的差距，研究人员将为当地高等教育机构的学生提供基因组学实践经验，并为学校的基因组学/生物信息学教育制定课程计划。

Many insects, including pests of agricultural and medical importance, bear symbiotic bacteria that provide essential nutrients to their insect hosts, but the composition and amount of nutrients transferred between the partners are largely unknown. This project will investigate insect-bacterial nutrient exchange in insects that feed on the extremely nutrient-poor diet of plant xylem sap. Exploiting recent advances in genomics and metabolic modeling, the investigators will quantify the capacity of both insect and bacteria to synthesize key nutrients, and then integrate these results in the form of metabolic models that describe the amount of each nutrient transferred between the partners. These models enable testing of two fundamental predictions: that nutrients produced in excess by one partner are required by other partners, achieving the nutritional efficiency that is required for insects to survive on xylem sap; and that the profile of nutrients received by the insects from their bacterial partners is defined by the overall metabolic network, and not simply the gene content of the bacteria. The integrated molecular understanding of the nutritional interactions between the insects and bacteria generated by this research will identify specific targets for novel pest control strategies against important xylem-feeding insect pests which transmit plant pathogens affecting citrus, grape, coffee and other crops. The project will provide training in state-of-the-art genomic and modeling methods for a postdoctoral researcher and graduate and undergraduate students. To address the increasingly recognized gap between research infrastructure and educational resources in sequence analysis and bioinformatics, the investigators will provide hands-on experience in genomics to students from local higher education institutions with limited genomics educational resources, and also develop lesson plans for genomics/ bioinformatics education in schools.