DISSERTATION RESEARCH: The role of phyllosphere microbiomes in plant species coexistence and plant-pathogen interactions

微生物是很小的物种，你用肉眼看不到它们。微生物生活在地球上每一种较大的有机体的表面和内部，形成了被称为较大宿主的“微生物群”。这项研究将重点放在对植物健康和性能有深远影响的植物微生物群上。这项研究将集中在微生物如何影响宿主对另一种微生物的抵抗力：一种致病真菌。通过实验操作微生物群、寄主物种以及是否存在致病真菌，研究人员将能够找出微生物群如何影响不同植物物种相互竞争和抵御疾病的能力。通过培养天然微生物群中的微生物并使用最先进的DNA测序方法，他们将开始确定微生物参与者如何影响植物健康。该项目将对一名研究生进行尖端生物信息学技术方面的培训。由于这项工作的一个成果将是确定如何以及是否给植物接种合适的微生物群来预防疾病，这项工作的结果还将有助于开发新的方法来抗击农作物中昂贵的病原体，并帮助土地管理者促进自然系统中的生物多样性。在过去的三十年里，植物-土壤反馈框架被用来实现理论和经验上的突破。植物地上组织中或地上组织中的叶圈微生物群落也同样多样，但目前的研究无法将叶圈微生物的存在和身份与更大的生态问题联系起来。在这个项目中，研究人员将测试病原体感染如何改变复合和异种叶圈微生物群落的适合性和生长结果，重点是这些微生物群落的真菌成分。下一代测序技术将与依赖培养的方法相结合，以研究叶圈中真菌群落聚集的机制。功能特性数据将收集在选定的真菌培养物上，作为植物-真菌和病原体-真菌相互作用的指标。然后，这种基于特征的方法将被用来确定在实验室中测量的真菌的特定特征是否可以用来了解它们在植物上的丰度和作用。这项工作有可能扩大科学界对叶圈群落组装的理解，以及不同叶圈群落单独或与病原体一起抑制或促进植物-物种共存的机制。

Microorganisms are species that are so small that you cannot see them with the naked eye. Microorganisms live all over the surfaces and inside of every type of larger organism on the planet, forming what is known as the "microbiome" of the larger hosts. This research will focus on the microbiomes of plants, which have profound impacts on plant health and performance. This research will focus on how microbiomes affect resistance of a host to another microorganism: a disease-causing fungus. By experimentally manipulating combinations of microbiomes, host species, and whether or not the disease-causing fungus is present, the researchers will be able to find out how microbiomes affect the ability of different plant species to compete with one another and to resist disease. By growing microbes found in natural microbiomes and by using state-of-the-art DNA sequencing approaches, they will begin to identify how important microbial players affect plant health. This project will involve the training of a graduate student in cutting-edge bioinformatics techniques. Because one outcome of this work will be to identify how and whether inoculating plants with the right microbiome protects against disease, the results from this work will also contribute to the development of new approaches to fighting costly pathogens in crops, and to helping land managers promote biodiversity in natural systems. In the past three decades, the plant-soil feedback framework has been used to achieve theoretical and empirical breakthroughs. Phyllosphere microbial communities, which reside in or on aboveground plant tissues, are similarly diverse, but current research suffers from an inability to connect presence and identity of phyllosphere microbes to larger ecological questions. In this project, researchers will test how pathogen infection alters the fitness and growth outcomes of con- vs. heterospecific phyllosphere microbial communities, with a focus on the fungal constituents of these microbiomes. Next-generation sequencing technologies will be combined with culture-dependent approaches to study the mechanisms of fungal community assembly in the phyllosphere. Functional trait data will be collected on select fungal cultures as metrics of plant-fungal and pathogen-fungal interactions. This trait-based approach will then be used to determine whether specific traits of the fungi measured in the lab can be used to understand their abundance and role on plants. This body of work has the potential to expand the scientific community's understanding of phyllosphere community assembly, and the mechanisms by which different phyllosphere communities inhibit or facilitate plant-species coexistence on their own or in conjunction with pathogens.