DISSERTATION RESEARCH: Exploring convergence within pitcher plant microcosms

了解宿主或栖息地内驱动群落形成的因素对全球气候变化、人类健康和微生物生态具有重要意义。当寄主物种转移位置时，其他共生体是否可以替代原栖息地的共生体？猪笼草有改良过的叶子，可以收集水分和微生物，还可以捕捉昆虫，消化昆虫作为营养物质。这些猪笼草可以被认为是人类肠道的植物类似物，研究它们的微生物群落是如何形成的，如何相互作用，以及如何协助宿主消化，可以让我们了解我们自己的肠道居民。该项目将包括为美国和马来西亚学生提供培训机会，并将促进与马来西亚婆罗洲科学家的合作和交流。研究人员将合作为马来西亚研究中心创建教育展览，猪笼草的复杂生态将通过哈佛自然历史博物馆的家庭项目与儿童和成人分享。形式和功能的趋同在生命的所有领域都很常见，因为在地理上遥远的地方，类似的选择力量塑造了进化的变化。肉食性植物的猪笼草是趋同进化的精美例子：猪笼草的形态和功能在不同生物地理区域的三个遥远的植物谱系中分别进化。本研究调查了与投手有关的生物是否在其生态相互作用的性质中表现出类似的收敛模式。它将比较四个不同王国的群落模式和功能，在趋同宿主中。以北美的Sarracenia和东南亚的Nepenthes两属猪笼草为研究对象，通过真菌、细菌和原生生物的DNA测序，确定不同猪笼草种类和采集地点的微生物群落组成。猪笼草昆虫和微生物在聚合进化寄主上定居的能力将被研究，方法是将猪笼草植物放置在撒拉撒属植物的栖息地，并进行人工控制，以观察昆虫和微生物是否以及如何在不熟悉的寄主上定居。一项实验室实验将比较原生和趋同进化的微生物群落在促进营养有限的猪笼草从猎物中吸收氮方面的作用。最后，为了确定居民的群落模式是否相似，将使用宏基因组分析，通过统计和系统发育分析，并使用零模型，对Sarracenia和Nepenthes昆虫和微生物群落的类群，群落模式和结构因素的相似性进行测试，以检查会聚猪笼草宿主中的群落功能能力。

Understanding the factors driving community formation within a host or habitat has implications for global climate change, human health, and microbial ecology. As host species shift location, can other symbionts substitute for those from the original habitat? Pitcher plants have modified leaves that collect water and microbes, and trap insects that are digested for nutrients. These pitchers can be thought of as plant analogs to the human gut, and studying how their microbial communities form, interact with each other, and assist with host digestion could inform our understanding of our own gut inhabitants. The project will involve training opportunities for American and Malaysian students, and will foster cooperation and networking with scientists in Malaysian Borneo. The researchers will work collaboratively to create educational exhibits for the Malaysian research center, and the complex ecology of pitcher plants will be shared with children and adults through a Harvard Museum of Natural History family program.Convergence of form and function is common in all domains of life, because similar selective forces in geographically distant locations shape evolutionary change. Pitchers of carnivorous plants are exquisite examples of convergent evolution: pitcher plant morphology and function has evolved separately in three distant plant lineages in different biogeographic regions. This study investigates whether the organisms associated with pitchers show similar patterns of convergence in the nature of their ecological interactions. It will compare community pattern and function across four different kingdoms, within convergent hosts. With two genera of pitcher plants, Sarracenia in North America and Nepenthes in Southeast Asia, the microbial community composition across different pitcher plant species and collecting sites will be determined by DNA sequencing of the fungal, bacterial, and protist inhabitants. The ability of pitcher plant insects and microbes to colonize a convergently evolved host will be investigated by placing Nepenthes plants in a Sarracenia habitat, along with artificial controls, to see if and how insects and microbes colonize unfamiliar hosts. A laboratory experiment will compare native and convergently evolved microbial communities in facilitating the nutrient-limited pitcher plants in nitrogen uptake from prey. Finally, to determine if community patterns of inhabitants are similar across convergent hosts the similarity of taxa, community patterns, and factors structuring communities in Sarracenia and Nepenthes insect and microbial associates will be tested using metagenomic analyses to examine community functional capacity within convergent pitcher plant hosts by statistical and phylogenetic analyses, and with null models.