MCA: Using phylogenetic comparative methods to link plant-soil interactions, including with pathogens and mutualists, with physiological mechanisms across Rhododendron

植物与土壤微生物的相互作用，包括病原体和互助体，对植物的健康、多样性、分布和丰度至关重要。这项研究的很大一部分缺失了进化史和生理机制之间的联系。这项工作探索了这样一种假设，即疾病耐受性在一定程度上是由对水的生理适应形成的，这种适应平衡了水分保持和碳获取之间的基本权衡。由于根腐病等疾病限制了人们获得水的途径，因此对水分胁迫的生理适应可能是理解疾病耐受性的关键。同样，地下互助体的存在也可能通过生理机制调节疾病耐受性。为了探索这些问题，研究人员将整合不同杜鹃花分类群的生理学和微生物方法。杜鹃为这项研究提供了一个理想的系统，因为不同物种对一种入侵的植物病原体(肉桂疫霉)的疾病敏感性存在差异。肉桂疫霉可引起根腐病，可侵染5000多种植物。了解这种相互作用的机制可以改进抗逆性和抗病作物的选择。确定菌根真菌互助者的有益影响也将提高园艺成果，包括为苗圃行业培育更健康的植物。该项目将使职业生涯中期的科学家有机会学习新的生理学和微生物学工具，应用于本项目和未来的项目。这项工作将加强PI的职业目标，即开发一个生理和机械研究计划，加深对植物-土壤相互作用的了解，晋升为教授，并培训一个多样化的生态学和生理学实验室。PI和合作者将为不同的研究生和本科生研究人员提供培训。招募工作将利用现有的项目，如麦克奈尔学者和凯斯西储大学的北极星联盟。这名研究人员将进行常见的花园和温室实验，以探索疾病易感性的生理和系统发育决定因素。在实验水分梯度上种植20种杜鹃，将测试对水分胁迫的反应是否受到进化历史的影响。温室实验将测试生理机制如何影响病原菌的耐受性。另一项实验将探索菌根互助者如何改变生理特征和疾病易感性。这项职业发展中期奖还将培训PI的尖端植物生理技术，包括测量膨胀损失点，将培训研究生植物生理学和生态学，并将为本科生提供培训机会。这项工作还将包括开发一个开放获取的数据库RA-LEAFY，以利用相当多的杜鹃和杜鹃花爱好者社区，并为不同的学生和社区成员创造参与科学活动的机会。通过提供进入科学研究的入口，这项工作将促进科学工作者招募不同的人才。这一奖项反映了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。

Plant interactions with soil microbes, including pathogens and mutualists, are critical for plant health, diversity, distribution, and abundance. Missing from much of this research is the link between evolutionary history and physiological mechanisms. This work explores the hypothesis that disease tolerance has been shaped in part by physiological adaptations to water, which balance fundamental tradeoffs between water retention and carbon acquisition. Because diseases like root rot limit access to water, physiological adaptations to water stress may be essential to understanding disease tolerance. Similarly, the presence of belowground mutualists may also mediate disease tolerance through physiological mechanisms. To explore these issues, the investigator will integrate physiological and microbial approaches across diverse Rhododendron taxa. Rhododendron provide an ideal system to conduct this research because of the variation among species in disease susceptibility to an invasive plant pathogen (Phytophthora cinnamomi). Phytophthora cinnamomi causes root rot disease and can infect over 5000 plant species. Understanding the mechanisms governing this interaction can improve selection for stress and disease tolerant crops. Characterizing the beneficial effects of mycorrhizal fungal mutualists also will enhance horticultural outcomes, including leading to healthier plants for the nursery industry. The project will give a mid-career scientist the opportunity to learn new physiological and microbiological tools to be applied to this and future projects. This work will enhance the PI’s career goals of developing a physiological and mechanistic program of study, deepening the understanding of plant-soil interactions, progressing toward promotion to Professor, and training a diverse lab in ecology and physiology. The PI and collaborators will provide training for diverse graduate and undergraduate researchers. Recruitment efforts will leverage existing programs such as the McNair Scholars and the North Star Consortium at Case Western Reserve University.This investigator will conduct common garden and greenhouse experiments to explore the physiological and phylogenetic determinants of disease susceptibility. Growing 20 Rhododendron species across an experimental water gradient will provide a test of whether responses to water stress are shaped by evolutionary history. A greenhouse experiment will test how physiological mechanisms influence pathogen tolerance. Another experiment will explore how mycorrhizal mutualists modify physiological traits and disease susceptibility. This mid-career advancement award will also train the PI in cutting edge plant physiological techniques, including the measurement of turgor loss point, will train a graduate student in plant physiology and ecology, and will provide training opportunities for undergraduate researchers. This work will also include the development of an open access database, RA-LEAFY, to tap into the considerable community of enthusiastic Rhododendron and Azalea hobbyists and generate opportunities for scientific engagement for diverse students and community members. By providing an accessible entry point into scientific research, this work will enhance recruitment of diverse talent to the scientific workforce.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.