Investigating wetland plant mycobiomes to develop appropriate analogues for paleomycological inquiry

研究湿地植物真菌生物组以开发适合古真菌学研究的类似物

• 批准号: RGPIN-2022-04503
• 负责人: Klymiuk, Ashley
• 金额: $ 2.11万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744774
• 关键词: Investigating; wetland; plant; mycobiomes; develop

Although interactions between plants and fungi are ubiquitous in modern ecosystems and are thought to have been integral to the establishment of early terrestrial floras, the fossil record of plant-fungal interactions is sparse. Moreover, every fossil plant assemblage that contains root-associated fungi represents a wetland environment. As such, our understanding of the fossil record of plant-microbe interactions is biased towards plants living in, or near, inundated soils. The ecology of these interactions has, however, been consistently interpreted in accordance with models of plant-microbe interaction developed in subaerially exposed soil systems. Wetland soils are biogeochemically hostile environments primarily controlled by frequent anoxia with reduction-oxidation dynamics unparalleled in subaerial (fully terrestrial) soils; plant-fungal interactions in these settings have yet to be comprehensively addressed. The long-term goal of this research program is to utilize insights gained through study of contemporary plant-fungal interactions in wetland ecosystems, in order to better contextualize plant-fungal interactions in fossil wetland assemblages. The proposed research is focused on developing baseline data for root mycobiome community diversity and ecological drivers in contemporary wetlands. Studying biogeochemically-appropriate modern analogues for fossil assemblages will improve interpretation of plant-fungal interaction in the fossil record, and simultaneously establish a framework for future ecological investigations of contemporary wetlands. Short term objectives of this proposal are: 1) Evaluating host-specificity of rhizosphere mycobiome constituents across hydrologic, biogeochemical, and climatic gradients, using a combination of targeted amplicon (NL1/NL4, ITS) metagenomic sequencing and culturing (PhD 1). 2) Investigating congruence of wetland plant mycobiomes with rhizosphere spore banks, using metagenomic and visual assays (PhD 2). 3) Developing a culture library and database of host-fungal associations (conducted by MSc students, undergraduate researchers), as a line of evidence independent of sequencing, and for future investigation of plant physiologic response to individual constituents of root mycobiomes, fungal species discovery, and evaluating diversity of endohyphal bacteria. These investigations build foundational knowledge in as-yet understudied biological systems. From a paleobiology perspective, these studies will facilitate productive approaches to studying the fossil record of plant-fungal interactions, and more accurate interpretations of fossil floras during key intervals of plant evolution and global climatic change. In its initial 5 years, this research program will train 3 summer undergraduate researchers per year in field ecology and laboratory mycology methods, and 5 graduate researchers in metagenomic, culturing, and ecology data collection and analysis.

尽管植物和真菌之间的相互作用在现代生态系统中无处不在，并且被认为是早期陆生植物区系建立的组成部分，但植物-真菌相互作用的化石记录却很少。此外，每一个包含根相关真菌的化石植物组合都代表了一个湿地环境。因此，我们对植物-微生物相互作用的化石记录的理解偏向于生活在被淹没的土壤中或附近的植物。然而，这些相互作用的生态学一直被解释为与在地下暴露的土壤系统中开发的植物-微生物相互作用模型一致。湿地土壤是生物地球化学上不利的环境，主要由频繁的缺氧控制，其还原-氧化动力学在陆地土壤中是无与伦比的；植物与真菌在这些环境中的相互作用尚未得到全面解决。本研究计划的长期目标是利用通过研究湿地生态系统中当代植物-真菌相互作用获得的见解，以便更好地了解化石湿地组合中植物-真菌相互作用的背景。提出的研究重点是建立当代湿地根真菌群落多样性和生态驱动因素的基线数据。研究生物地球化学上合适的化石组合的现代类似物将改善化石记录中植物-真菌相互作用的解释，同时为当代湿地的未来生态调查建立一个框架。本建议的短期目标是：1)利用目标扩增子（NL1/NL4， ITS）宏基因组测序和培养，评估根际真菌群落成分在水文、生物地球化学和气候梯度上的宿主特异性（博士1）。2)利用宏基因组和视觉分析，研究湿地植物真菌群落与根际孢子库的一致性（博士2）。3)建立宿主-真菌关联的培养库和数据库（由硕士研究生和本科生研究）。作为独立于测序的证据线，并为未来研究植物对根真菌群落单个成分的生理反应，真菌物种发现和评估菌丝内细菌多样性提供了证据。这些调查在尚未充分研究的生物系统中建立了基础知识。从古生物学的角度来看，这些研究将有助于研究植物与真菌相互作用的化石记录，并更准确地解释植物进化和全球气候变化关键时期的化石区系。在最初的5年，该研究项目每年将培养3名野外生态学和实验室真菌学方法方面的暑期本科生研究人员，以及5名宏基因组学、培养和生态学数据收集和分析方面的研究生研究人员。