RoL: RUI: Collaborative Research: Understanding the Ecological and Genomic Bases of Local Adaptation in an Obligate Pollination Mutualism

所有生物都必须管理来自环境的压力以及与其他生物的相互作用。生物学家长期以来一直认为，与捕食者、竞争者和互助者的相互作用是生命史上的一股强大力量，有助于刺激新物种的形成。然而，很难测试生物之间的相互作用是否比物理环境的影响更重要，如热，冷冻或干旱。这个项目利用了生活在莫哈韦沙漠极端环境中的物种之间独特的相互作用来进行比较。约书亚树，这种长满尖刺、扭曲的树在莫哈韦随处可见，没有丝兰蛾的帮助，它就不能结出果实。约书亚树的花朵似乎适应了飞蛾，但树木也经历了极端的高温和干旱，似乎这些物理的影响，非生命环境也影响了它们的生存。“约书亚树基因组计划”将利用基因测序和对约书亚树苗的实验来研究树木如何科普沙漠不同地区的不同气候。然后，项目合作者可以将气候对约书亚树种群的影响与它们与丝兰蛾相互作用的影响进行比较。该团队还将邀请莫哈韦地区的志愿者和科学教师在他们自己的后院测量和监测约书亚树的数量。通过第一次详细研究约书亚树对气候的适应，这个项目将有助于回答地球生命史上一个长期存在的问题--生物之间的相互作用还是物理环境之间的相互作用更重要--并开发科学工具和社区合作伙伴关系，以帮助保护约书亚树在不断变化的未来气候。约书亚树基因组计划是一个合作，生态学家，遗传学家，生物信息学家，植物生理学家在威拉米特大学，加州州立大学北岭，亚拉巴马和夏威夷大学，以及美国地质调查局西部生态研究中心。合作者将在莫哈韦周围的普通花园地点种植约书亚树苗，监测它们的生长和生理表现，并使用RNA测序来识别在不同气候下差异表达的基因。该团队将完成一个约书亚树参考基因组，并将其与基因表达结果一起设计一个序列捕获阵列，用于数百棵树的靶向测序。靶向测序将使他们能够对有助于幼苗在普通花园中存活和表现的生理性状以及与丝兰蛾授粉相关的花性状进行全基因组关联研究（GWAS）。然后，该团队将使用景观基因组分析来识别基因，这些基因显示出当地适应气候和蛾类特征变化的特征。与此同时，该团队将与莫哈韦地区的保护非营利组织和K-12教育工作者合作，扩大参与性科学计划，培训志愿者调查约书亚树种群的人口统计，记录有多少树开花和结果，以及有多少小树更新种群。最后，该团队将利用他们的遗传分析结果来建立一个基因组预测协议，该协议可以仅从遗传数据中预测约书亚树种群的生理和授粉相关性状。该团队将使用该协议来预测志愿者调查所描述的地点的树木特征，并测试人口预测特征值与人口健康之间的关系。这将使他们能够确定影响约书亚树在当前条件下的适应性的具体特征，并将提供一种工具来评估约书亚树种群在未来气候中的适应性。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。

All living things must manage stress from their environment and interactions with other living things. Biologists have long believed that interactions with predators, competitors, and helpful mutualists are a powerful force in the history of life, helping to spur the formation of new species. However, it is difficult to test whether interactions between living things have been more important than the effects of the physical environment like heat, freezing, or drought. This project makes that comparison by taking advantage of a unique interaction between species that live in the extreme environments of the Mojave Desert. Joshua trees, the spikey, twisted-looking trees found across the Mojave, cannot produce fruit without the help of yucca moths. Joshua tree flowers appear to be adapted to the moths, but the trees also experience extreme heat and drought, and it seems likely that these effects of the physical, nonliving environment also impact their survival. The Joshua Tree Genome Project will use genetic sequencing and experiments with Joshua tree seedlings to study how the trees cope with different climates in different parts of the desert. The project collaborators can then compare the effects of climate on Joshua tree populations to the effects of their interaction with yucca moths. The team will also engage volunteers and science teachers across the Mojave region to measure and monitor Joshua tree populations in their own backyards. By examining the Joshua tree's adaptation to climate in detail for the first time, this project will help to answer a longstanding question in the history of life on Earth — whether interactions between living things or the physical environment have been more important — and develop scientific tools and community partnerships that can help protect Joshua trees under changing future climates.The Joshua Tree Genome Project is a collaboration of ecologists, geneticists, bioinformaticians, and plant physiologists at Willamette University, California State University Northridge, the Universities of Alabama and Hawaii, and the US Geological Survey Western Ecological Research Center. The collaborators will plant Joshua tree seedlings at common-garden sites around the Mojave, monitor their growth and physiological performance, and use RNA sequencing to identify genes that are differentially expressed in different climates. The team will complete a Joshua tree reference genome and use it with the gene expression results to design a sequence capture array for targeted sequencing of hundreds of trees. Targeted sequencing will allow them to perform genome-wide association study (GWAS) of physiological traits that contribute to seedlings’ survival and performance in the common gardens, and of floral traits related to pollination by yucca moths. The team will then use landscape genomic analyses to identify genes showing signatures of local adaptation to variation in climate and moth traits. Meanwhile, the team will expand a participatory science program working with Mojave-regional conservation nonprofits and K-12 educators to train volunteers to survey the demography of Joshua tree populations, recording how many trees flower and produce fruit, and how many young trees are present to renew the population. Finally, the team will use the results of their genetic analyses to build a genomic prediction protocol that can project the physiological and pollination-related traits of a Joshua tree population from genetic data alone. The team will use this protocol to predict the traits of trees at sites profiled by volunteer surveys, and test for relationships between populations’ predicted trait values and their demographic health. This will allow them to identify specific traits that influence the fitness of Joshua trees in current conditions, and would provide a tool to assess the resilience of Joshua tree populations in future climates.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.