CAREER:Novel interactions in novel conditions: consequences of disrupting historical plant-fungal interactions for tree responses to environmental variation

当一个植物物种受到一个地区气候变暖或干燥的压力时，它有三种选择：迁移到一个气候适宜的新地方，通过进化或适应发展对新气候的耐受性，或者在该地区灭绝。然而，我们现在知道，所有植物都与高度多样化的微生物群落（即真菌）相关联，这些微生物群落可以帮助植物获取土壤中的水分和养分。本研究将调查树种是否可以利用与其根区相关的真菌来增加其对干燥条件的耐受性。这项研究还将测试，破坏植物和与其根相关的真菌之间的历史关系，对在新地区生长的树苗是有利还是有害。此外，这个项目将建立一个公民科学家网络，他们将帮助收集美国东部几种树种的根系样本。这些样本将被用于一门新的本科课程，在这门课程中，学生将使用新兴的分子生物学和计算工具来识别和绘制森林土壤中真菌物种的当前分布。总之，这些新知识可能有助于预测温带森林将如何应对不断变化的环境，并有可能通过保护或操纵土壤微生物来促进森林健康的新工具。对植物来说，根内和根周的微生物群落可以调节对土壤水分和养分的获取。这些群落的改变可能为植物对环境变化的耐受性表型变异提供了另一种来源。随着植物和微生物种群分布的转移，植物种群、微生物类群和非生物条件之间的历史关系将被破坏。该项目将研究新的植物-微生物相互作用如何影响当前范围内外的树木建立。为了实现这一目标，研究者将结合现场实验和控制环境，操纵树苗源种群和土壤微生物群落，以及根际真菌群落的分子特征。具体而言，该项目将1)确定树木种群是否适应当地微生物群落，以及将其与对气候和土壤梯度的适应进行比较；2)测试与根相关的微生物群落是否在面对变化的环境时调节范围的扩张和收缩；3)记录根际微生物类群目前在宿主范围内的分布情况，以及这些分布如何在快速的环境变化下发生变化。

When a plant species is stressed by warming or drying climates in an area it has three options: move to a new location that has a suitable climate, develop tolerance to the new climate through evolution or acclimation, or go extinct in the area. However, we now know that all plants exist in association with a highly diverse community of microorganisms (i.e. fungi), which can help plants access water and nutrients in soil. This research will investigate whether tree species can utilize the fungi associated with their root zones to increase their tolerance to drying conditions. The study will also test whether disrupting the historical relationships between plants and the fungi associated with their roots, will benefit or harm tree seedlings as they establish in new areas. Additionally, this project will establish a network of citizen scientists who will aid in collecting root samples from several tree species across the eastern United States. These samples will then be used in a new undergraduate course in which the students use emerging molecular biology and computational tools to identify and map the current distribution of fungal species in forest soils. Together, this new knowledge may help predict how temperate forests will respond to changing environments, and potentially lead to new tools to promote forest health by conserving or manipulating soil microbes. For plants, microbial communities in and around roots can mediate access to soil moisture and nutrients. Alterations of these communities may provide an alternative source of phenotypic variation in plant tolerance to environmental changes. As both plant and microbial populations shift their distributions, historical relationships between plant populations, microbial taxa, and abiotic conditions will be disrupted. This project will investigate how novel plant-microbial interactions may affect tree establishment within and beyond current ranges. To accomplish this, the investigator will use a combination of experiments in the field and controlled settings which manipulate tree seedling source population and soil microbial communities, along with and molecular characterization of rhizosphere fungal communities. Specifically, the project will 1) determine whether tree populations are adapted to local microbial communities, and how this compares with adaptation to climatic and edaphic gradients, 2) test whether root-associated microbial communities mediate range expansion and contraction in the face of changing environments, and 3) document how rhizosphere microbial taxa are currently distributed across host ranges, and how these distributions may shift under rapid environmental changes.