NSF Postdoctoral Fellowship in Biology FY 2020

这项行动资助了2020财年的NSF生物学博士后研究奖学金，综合研究调查了基因组，环境和表型之间的生命相互作用的规则。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。许多生物相互受益，这些关系往往涉及多个物种。为什么这些互动不专门针对一个单一的“最佳”合作伙伴？这项研究提出了一个新的生活规则来解释这个悖论：投资组合效应，预测存在不同的合作伙伴，因为没有一个合作伙伴在所有条件下都是“最好的”。像投资者一样，生物体可能需要广泛的关系组合，以防环境发生变化。本项目研究组合的影响外生菌根互惠，需要约60%的树木。外生菌根植物在根部为几十种真菌提供糖分，以换取养分和水分。由于树木寿命长达数十年，它们必须承受从冬季风暴到干旱的环境变化。它们的真菌可能在这些环境中提供不同的共生效益。因此，树木可能需要随着时间的推移保持真菌多样性。这项研究测试了幼苗补充的组合效应，以改善对森林如何应对环境变化的预测。该研究还将培养生态学领域的本科生研究人员，并将支持面向中学生的公开讲座和科学研讨会。该项目结合温室实验、基因表达分析和数学建模来研究组合效应。该研究员将使用道格拉斯冷杉和真菌文化，以了解共生真菌的功能如何在压力下变化。测试的压力因素-干旱和氮污染-代表了许多森林未来可能的环境条件。研究员将测量树苗在与每种真菌相关时耐受压力的程度，并将测量环境中真菌基因的表达，将基因组与表型联系起来。然后，一个统计模型将模拟与所测试的真菌相关的幼苗种群在压力生长季节的承受能力。组合效应预测，具有更多样化共生体的幼苗群体将更稳定地生长和生存。最后，一个生态进化模型将研究植物谱系将如何专门化，这取决于环境变化的频率。投资组合效应预测，可变的环境应该选择不同的（而不是专门的）协会。该研究员将与她的导师一起学习数学建模，并将与法国的专家合作，以提高她的元转录分析技能。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2020, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Many living things benefit each other, and these relationships often involve multiple species. Why are these interactions not specialized on a single “best” partner? This research proposes a new Rule of Life to explain this paradox: Portfolio effects, predicting that diverse partners exist because no single partner is the “best” under all conditions. Like investors, organisms may need a broad portfolio of relationships, in case the environment changes. This project examines portfolio effects in the ectomycorrhizal mutualism, required by roughly 60% of trees. Ectomycorrhizal plants feed sugars to dozens of fungi on their roots in exchange for nutrients and water. Since trees live for decades, they must withstand environmental variation, from winter storms to droughts. Their fungi may offer different symbiotic benefits in these environments. Thus, trees may need to maintain fungal diversity over time. This research tests for portfolio effects in seedling recruitment, to improve predictions for how forests will respond to environmental variation. This research will also train undergraduate researchers underrepresented in ecology, and will support public lectures and a science workshop for middle school students.This project combines greenhouse experiments, gene expression analysis, and mathematical modeling to investigate portfolio effects. The Fellow will use Douglas fir and fungal cultures to understand how symbiotic fungal function varies under stress. The stressors tested – drought and nitrogen pollution – represent likely future environmental conditions in many forests. The Fellow will measure how well tree seedlings tolerate stress when associated with each fungus, and will measure fungal gene expression across environments, connecting genomes to phenotypes. Then, a statistical model will simulate how well a population of seedlings associated with the tested fungi would withstand a stressful growing season. Portfolio effects predict that populations of seedlings with more diverse symbionts will grow and survive more consistently. Finally, an eco-evolutionary model will examine how specialized a plant lineage will become, depending upon how frequently the environment shifts. Portfolio effects predict that variable environments should select for diverse (not specialized) associations. The Fellow will learn mathematical modeling with her mentor, and will collaborate with experts in France to enhance her metatranscriptomic analysis skills.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.