Ecological and evolutionary consequences of climate warming for fungal pathogens

预计环境变化将影响全球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决定疾病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善疾病预测和管理也至关重要。真菌病原体引起许多疾病，威胁到农业和保护关注的宿主。然而，人们对环境变化对真菌病原体的影响知之甚少。这主要是因为真菌具有复杂的生命周期，这对研究气候具有挑战性。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变暖对真菌病原体的影响。这些模型将模拟几种类型的病原体在不同气候情景下的感染传播。数据收集和分析将侧重于常见植物及其真菌病原体。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。在这门课程中，学生将分析由世界各地的公民科学家收集的患病植物的图像。学生还将通过圣路易斯华盛顿大学的泰森本科生奖学金项目参加实地和实验室研究。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。大多数真菌能够无性繁殖和有性繁殖，并且生命周期的每个阶段都可以依赖于温度。在温带地区，许多真菌病原体从春季到初秋产生无性（克隆）孢子，然后在秋末温度下降时进行有性繁殖的越冬阶段。变暖会改变无性繁殖孢子的产生、存活和传播，以及有性繁殖和基因重组的频率。在Aim 1中，研究人员将建立一个通用的元种群模型，以评估温度对病原体生活史特征的影响如何导致不同气候情景下病原体流行率和基因型多样性的变化。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Aim 2中，研究人员将通过实验量化沿着气候梯度收集的真菌植物病原体生活史特征的热性能曲线。他们将测试病原体对当地热环境和野生寄主植物种群的适应性。在目标3中，研究人员将评估气候与局灶病原体的发生和基因型多样性之间的关系。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元种群模型的一个版本的预测进行比较。该项目将整合以课程为基础的本科生研究体验课对学生的培训，以及对本科生的数据管理和沟通培训。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.