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

当一种植物在一个地区受到气候变暖或干燥的压力时，它有三个选择：搬到一个气候适宜的新地点，通过进化或驯化培养对新气候的耐受性，或者在该地区灭绝。然而，我们现在知道，所有的植物都伴随着高度多样化的微生物群落(即真菌)，这可以帮助植物获得土壤中的水分和养分。这项研究将调查树种是否可以利用与其根区相关的真菌来提高它们对干燥条件的耐受性。这项研究还将测试破坏植物与与其根部相关的真菌之间的历史关系，当树苗在新的地区建立时，是有利于还是损害树苗。此外，该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个树种的根样本。然后，这些样本将用于一门新的本科课程，在该课程中，学生们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。总而言之，这一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，并可能导致通过保护或操纵土壤微生物来促进森林健康的新工具。对于植物来说，根部及其周围的微生物群落可以调节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提供了另一种表型变异的来源。随着植物和微生物种群分布的改变，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。这个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和之外的树木建立。为了实现这一目标，研究人员将使用田间实验和控制环境相结合的方法来操纵树苗来源种群和土壤微生物群落，以及根际真菌群落的分子特征。具体地说，该项目将1)确定树木种群是否适应当地微生物群落，以及这与适应气候和土壤梯度相比如何；2)测试与根相关的微生物群落是否在不断变化的环境中调节范围的扩大和收缩；3)记录根际微生物类群目前如何在宿主范围内分布，以及这些分布在快速环境变化下可能如何变化。

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.