NSF Postdoctoral Fellowship in Biology FY 2021: Spatially Resolving the Cellular Landscape of Arbuscular Mycorrhizal Symbiosis with M. truncatula and D. epigaea

本行动资助2021财年美国国家科学基金会植物基因组生物学博士后研究奖学金。该奖学金支持奖学金获得者在主办实验室的研究和培训计划，该奖学金获得者还提出了扩大生物学参与的计划。Trevor Tivey的研究和培训计划的标题是“使用空间RNA-Seq和内循环分析来空间解决与Medicago truncatula和diverspora epigaea的丛生菌根共生的细胞景观”。该奖学金的主办机构是博伊斯·汤普森研究所，赞助科学家是玛丽亚·哈里森博士。种类繁多的植物和数量有限的土壤真菌在一种称为丛枝菌根共生的关系中相互作用。植物和真菌之间的这种地下关系发生在植物的根细胞内，并帮助植物和真菌获得关键的营养物质。控制这种共生关系的关键植物基因已经被确定，但是在定植过程中植物和真菌基因表达的时间和调控是复杂的，需要进一步了解。为了描述这种相互作用，该项目将在精细的空间分辨率下测量共生过程中的植物和真菌转录本，并沿着真菌定植的梯度确定细胞之间的基因表达差异。该项目的结果将有助于开发研究根与微生物相互作用的资源，并使这些方法能够应用于主要作物中解决类似问题。在此过程中，该项目将促进在生物学领域代表性不足的本科生的研究参与，并通过外展和教学支持当地社区的学生。该项目将使用空间mRNA-Seq来绘制植物和真菌转录组图，并沿着定殖的时空梯度比较所有植物细胞类型中的基因表达，从而创建植物-真菌基因共表达网络，并将内倍体的转录组学和显微镜证据关联起来，以确定候选基因途径。为了解决对内倍性的控制，植物突变体、细胞周期标记和图像分析将用于破坏共生信号并检查对内倍性的影响。对AM共生中内倍体的重要性的进一步了解有可能为植物中共生和寄生生物营养定植的机制提供信息。空间转录组数据集将在NCBI基因表达综合数据库中公开提供。在未来的植物细胞周期和生物营养相互作用的实验研究中，将共享M. truncatula细胞周期标记系和内循环调节突变体。关键词：宿主微生物，菌根，空间转录组学，核内复制，定植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。

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2021. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Trevor Tivey is "Using Spatial RNA-Seq and endocycle analyses to spatially resolve the cellular landscape of arbuscular mycorrhizal symbiosis with Medicago truncatula and Diversispora epigaea". The host institution for the fellowship is the Boyce Thompson Institute and the sponsoring scientist is Dr. Maria Harrison.A broad diversity of plants and a limited group of soil fungi interact together in a type of association known as arbuscular mycorrhizal symbiosis. This underground relationship between plants and fungi takes place within plant root cells, and helps both plants and fungi acquire critical nutrients. Key plant genes governing this symbiosis have been identified, however the timing and regulation of plant and fungal gene expression during colonization is complex and requires further understanding. To characterize this interaction, this project will measure plant and fungal transcripts during symbiosis at a fine spatial resolution and identify gene expression differences between cells along a gradient of fungal colonization. Results from this project will help to develop resources for the study of root-microbe interactions and enable the application of these methods to address similar questions in major crops. In the process, this project will promote research participation of undergraduates who are underrepresented in biology and support students from the local community through outreach and teaching.This project will use spatial mRNA-Seq to map the plant and fungal transcriptomes and compare gene expression in all plant cell types along a spatiotemporal gradient of colonization, enable the creation of plant-fungal gene co-expression networks, and correlate transcriptomic and microscopical evidence of endoploidy to identify candidate gene pathways. To address the controls on endoploidy, plant mutants, cell cycle markers, and image analysis will be used to disrupt symbiosis signaling and to examine the effects on endoreduplication. An increased understanding of the significance of endoploidy in AM symbiosis has the potential to inform mechanisms of symbiotic and parasitic biotroph colonization in plants. Spatial transcriptome datasets will be made publicly available in the NCBI Gene Expression Omnibus. M. truncatula cell cycle marker lines and endocycle regulation mutants will be shared for future experimental studies of the plant cell cycle and biotrophic interactions.Keywords: host-microbe, mycorrhiza, spatial transcriptomics, endoreduplication, colonizationThis 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.