Ecological and evolutionary consequences of climate warming for fungal pathogens

环境变化预计将影响世界各地植物和野生动物的疾病风险。预测这些影响需要了解气候在确定疾病可能发生的时间和地点方面的作用。了解气候如何影响病原体进化对于改进疾病预测和管理也是至关重要的。真菌病原体导致许多疾病，威胁到农业和环境保护的宿主。然而，环境变化对真菌病原体的影响知之甚少。这在很大程度上是因为真菌具有复杂的生命周期，在气候方面的研究具有挑战性。例如，许多真菌在不同的气候条件下以不同的方式繁殖。研究人员将通过数学模型、实地研究和实验来确定气候变暖对真菌病原体的影响。这些模型将模拟不同气候情景下几种病原体感染的传播。数据收集和分析将集中在常见植物及其真菌病原体上。这些将在广泛的气候条件下进行研究。本科生将通过杜鲁门州立大学的生物学入门课程为该项目做出贡献。在这门课中，学生们将分析世界各地的民间科学家收集的患病植物的图像。学生还将被招募参加圣路易斯华盛顿大学泰森本科生研究员项目的实地和实验室研究。该项目的中心目标是确定气候变暖如何改变真菌病原体的生态和进化。大多数真菌既能进行无性繁殖，又能进行有性繁殖，生命周期的每个阶段都可能与温度有关。在温带地区，许多真菌病原体从春季到初秋季节产生无性(克隆)孢子，然后在晚秋气温降温时经历越冬阶段的有性繁殖。气候变暖将改变克隆孢子的产生、存活和扩散，以及有性繁殖和基因重组的频率。在目标1中，研究人员将开发一个通用的集合种群模型，以评估温度对病原菌生活史特征的影响如何导致不同气候情景下病原菌患病率和基因多样性的变化。他们将解决模型结果如何取决于病原体热生物学、交配系统和其他参数。在目标2中，研究人员将对沿着气候梯度收集的真菌植物病原体的生活史特征的热性能曲线进行实验量化。他们将测试病原体对热环境和野生寄主植物种群的局部适应情况。在目标3中，研究人员将评估气候与局部病原体的发生和基因多样性之间的关系。这一目标将通过实地调查、基因分型和公民科学项目以及基于课程的本科生研究经验来实现。这些数据将与为重点研究系统参数化的集合人口模型的一个版本的预测进行比较。该项目将把以课程为基础的本科生研究体验课程中的学生培训与对本科生的数据管理和通信培训相结合。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Environmental change is expected to impact the risk of disease for plants and wildlife worldwide. Predicting those impacts requires understanding the role of climate in determining when and where diseases can occur. Understanding how climate affects pathogen evolution is also essential for improving disease prediction and management. Fungal pathogens cause many diseases that threaten hosts of agricultural and conservation concern. However, effects of environmental change on fungal pathogens are poorly understood. This is largely because fungi have complex life cycles that are challenging to study with respect to climate. For example, many fungi reproduce in different ways under different climate conditions. The researchers will determine effects of warming on fungal pathogens using mathematical models, field studies, and experiments. The models will simulate spread of infections by several types of pathogens under different climate scenarios. Data collection and analysis will focus on common plants and their fungal pathogens. These will be studied over a wide range of climate conditions. Undergraduates will contribute to the project through an introductory biology course at Truman State University. In that course, students will analyze images of diseased plants that were collected by citizen scientists around the world. Students will also be recruited to participate in field and laboratory research through the Tyson Undergraduate Fellows program at Washington University in St. Louis.The central goal of this project is to determine how climate warming changes the ecology and evolution of fungal pathogens. Most fungi are capable of both asexual and sexual reproduction, and each phase of the life cycle can be temperature dependent. In temperate regions, many fungal pathogens produce asexual (clonal) spores from spring through early fall seasons and then undergo sexual production of an overwintering stage when temperatures cool in later fall. Warming should alter the production, survival, and dispersal of clonal spores as well as the frequency of sexual reproduction and genetic recombination. In Aim 1, the researchers will develop a general metapopulation model to evaluate how effects of temperature on pathogen life-history traits lead to changes in pathogen prevalence and genotypic diversity under different climate scenarios. They will resolve how model outcomes depend on pathogen thermal biology, mating system, and other parameters. In Aim 2, the researchers will experimentally quantify thermal performance curves for life history traits of a fungal plant pathogen collected along a climatic gradient. They will test for pathogen local adaptation to thermal regimes and wild host plant populations. In Aim 3, the researchers will assess relationships between climate and the occurrence and genotypic diversity of the focal pathogen. This aim will be accomplished through field surveys, genotyping, and a citizen science project coupled with a course-based undergraduate research experience. Those data will be compared to predictions from a version of the metapopulation model parameterized for the focal study system. The project will integrate student training in a course-based undergraduate research experience class with data management and communication training to undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.