DISSERTATION RESEARCH: Mechanisms of host preference in the ectomycorrhizal symbiosis

虽然互利互动在许多自然系统中很重要，但仍不清楚为什么有些系统涉及高度专业化的合作伙伴，而另一些则没有。这个项目研究了不同程度的特异性是如何进化的，以及在一种特殊类型的共生关系中的作用-真菌和许多温带森林植物之间的互利关系。本研究将联合收割机一种真菌与多个远亲寄主植物相结合，探讨真菌在与不同种类植物相互作用时，如何改变其共生行为。这项实验将深入了解这种重要的互惠共生中的共生植物-微生物通信，并将允许与病原体中的类似系统进行比较。在旧金山弗朗西斯科的城市青年科学丰富计划的推广也将发生。这项研究将使用RNA测序来确定外生菌根真菌Thelephora terrestris的多面手宿主偏好的遗传基础。来自四个科的六种植物将建立在微观世界中，并接种来自Thelephora terrestris的孢子。在共生成熟时，将用碳-13和氮-15标记微观世界，并收获植物，真菌和共生组织进行同位素分析和RNA测序。转录数据将与植物和真菌资源分配的稳定同位素富集测量相结合，并在不同的植物-真菌组合中进行比较。测量共生组织中的基因表达，同时跟踪资源分配将揭示哪些基因与改善的共生性能相关，从而在基因转录、生理功能和互利相互作用的稳定性之间提供强有力的联系。

Although mutually beneficial interactions are important in many natural systems, it remains unclear why some involve highly specialized partners, while others do not. This project investigates how different degrees of specificity have evolved and function in a particular type of symbiosis - a mutualistic relationship between a fungus and many temperate forest plants. This research will combine a fungus with multiple, distantly related host plants to investigate how the fungus alters its symbiotic behavior when interacting with different species of plants. This experiment will generate insight into symbiotic plant-microbe communication in this important mutualism, and will allow for comparison to similar systems in pathogens. Outreach to science enrichment programs for urban youth in San Francisco will also occur.This study will use RNA sequencing to determine the genetic basis of generalist host preference in the ectomycorrhizal fungus Thelephora terrestris. Six plant species from four families will be established in microcosms and inoculated with spores from Thelephora terrestris. At symbiotic maturity, microcosms will be labeled with carbon-13 and nitrogen-15 and plant, fungal, and symbiotic tissues will be harvested for isotope analysis and RNA sequencing. Transcriptional data will be combined with stable isotope enrichment measurements of plant and fungal resource allocation and compared across different plant-fungus combinations. Measuring gene expression in symbiotic tissues while simultaneously tracking resource allocation will reveal which genes are associated with improved symbiotic performance, providing a powerful link between gene transcription, physiological function, and the stability of mutualistic interactions.