COLLABORATIVE RESEARCH: Parsing the effects of host specificity and geography on plant-fungal symbioses under climate change

气候模型预测更高的温度，更多的降水变化，以及未来更多的极端天气事件。在这种不断变化的环境下，基础植物物种，促进其他物种的稳定条件和支持基本的生态系统过程，可能会受益于微生物合作伙伴，提高植物在极端气候条件下的生存。然而，微生物伴侣是否可以帮助缓冲生态系统对气候变化的影响仍然是未知的。这项研究调查了一种广泛存在但鲜为人知的真菌，它们通常生长在主要牧草的根部。该项目确定了这些真菌的益处如何随着干旱和高温胁迫的沿着梯度变化，在草种之间存在差异，并在地理区域之间转移。这项工作对于鉴定帮助植物在恶劣气候下生存和生长的真菌具有很高的希望。该团队将把研究活动整合到一个新的高中教师培训计划中，该计划侧重于服务不足的社区和一套中学研讨会的实验室模块。研究结果将揭示微生物伴侣在维持草地和牧场生产力方面的功能，提高在未来气候条件下保护、管理和恢复这些重要区域的能力。深入了解根内生菌的生物学有可能改变对植物如何应对干旱和高温的理解，就像对菌根真菌的研究推翻了植物如何获得营养的范式一样。该项目测试根相关真菌是否有益于主要的草原植物物种，这可能会减轻干旱和热浪期间净初级生产力的损失。这项工作解决了以下问题：（1）什么是相对重要的宿主物种的身份与地理和气候梯度在解释共生体丰度和组成的变化？(2)宿主物种身份和地理来源如何强烈地影响共生体在高温和干旱胁迫梯度上的利益？(3)共生体介导的压力改善可以从实验室环境中推广到预测现场结果吗？活动包括沿着纬度梯度的实地调查，根真菌的下一代高通量测序，大型真菌培养物收集的开发，操纵干旱和高温的多因素温室试验，以及利用现有的大型跨站点降雨实验的实地测试。该项目的新方面包括表征根相关真菌的组成沿着纬度梯度，测试的假设，共生体变得更有益于植物在增加非生物胁迫下，并确定内生根真菌如何影响植物宿主在田间条件下。

Climate models project higher temperatures, more variability in precipitation, and more extreme weather events in the future. Under such changing environments, foundation plant species, which promote stable conditions for other species and support fundamental ecosystem processes, may benefit from microbial partners that enhance plant survival during climate extremes. However, whether microbial partners can help buffer ecosystems against climate change remains unknown. This research investigates a widespread, but poorly known, group of fungi that commonly grow in the roots of dominant forage grasses. The project determines how the benefits of these fungi vary along gradients of drought and heat stress, differ among grass species, and shift across geographic regions. This work has high promise for identifying fungi that help plants survive and grow in stressful climates. Together, this team will integrate research activities into a new high school teacher training program that focuses on underserved communities and a set of laboratory modules for middle school workshops. Results will shed new light on the functions of microbial partners in maintaining grassland and rangeland productivity, improving the ability to conserve, manage, and restore these important areas in future climates.Deeper insight into the biology of root endophytes has the potential to transform understanding of how plants respond to drought and heat in the same way that studies on mycorrhizal fungi overturned paradigms about how plants acquire nutrients. This project tests whether root-associated fungi benefit dominant grassland plant species, which may moderate the loss of net primary production during droughts and heat waves. The work addresses the following questions: (1) What is the relative importance of host species identity versus geographic and climatic gradients in explaining variation in symbiont abundance and composition? (2) How strongly do host species identity and geographic origin influence the magnitude of symbiont benefits across gradients of heat and drought stress? (3) Can symbiont-mediated amelioration of stress be generalized from laboratory settings to predict outcomes in the field? Activities include field surveys along latitudinal gradients, next-generation high-throughput sequencing of root fungi, development of a large fungal culture collection, multi-factor greenhouse trials that manipulate drought and heat, and field tests that leverage existing, large, cross-site rainfall experiments. Novel aspects of this project include characterizing root-associated fungal composition along latitudinal gradients, testing the hypothesis that symbioses become more beneficial to plants under increased abiotic stress, and determining how endophytic root fungi affect plant hosts under field conditions.