DISSERTATION RESEARCH: Diversity and Functions of Interactions between the Liverwort Marchantia polymorpha and its Fungal Endophytes

论文研究：地钱及其内生真菌相互作用的多样性和功能

• 批准号: 1501826
• 负责人: Arthur Shaw
• 金额: $ 2.07万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501826&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Diversity; Functions; Interactions

Plants are defining components of natural ecosystems where they provide habitats for other organisms and influence the composition of soils and the atmosphere. Fungi, though less conspicuous, significantly affect the success of living plants in addition to breaking down dead matter. Fungi that live inside healthy plants, called fungal endophytes (hereafter simply endophytes), can benefit plants in many ways, including promoting growth, enhancing disease resistance, and increasing resilience to extreme conditions such as drought. Therefore, understanding how endophytes interact with their host plants is critical for managing wild ecosystems as well as increasing productivity in forestry and agriculture as plants respond to extreme weather in a changing climate. Endophytes have been found in nearly all plants sampled to date but there are few direct studies of the mechanisms behind their functions. This project investigates the diversity and functions of endophytes in a liverwort. This project will sample the diversity of endophytes in a model liverwort, Marchantia polymorpha, and investigate what factors influence this diversity. M. polymorpha grows well in the laboratory, so this project will directly test the effects of individual endophytes. Using genetic methods, the researcher will identify possible mechanisms behind the observed interactions. In addition, the study system developed in this project will provide many future opportunities for plant-endophyte interaction research.The researchers will collect Marchantia polymorpha plants from ten populations across the USA and characterize the diversity of the liverworts and their endophytes. Liverwort genotypes will be assessed using Restriction-site Associated DNA sequencing (RAD-seq) to sample sites throughout the genome. Internal fungal diversity will be sampled by surface sterilizing whole M. polymorpha plants, extracting total DNA, then amplifying and sequencing a fungal barcoding gene region. The researchers will test for correlations between fungal community diversity and composition, host genotypes, and population locations. These data will provide an ecological context for previous experiments testing the effects of cultured endophytes on M. polymorpha in laboratory growth assays. To investigate the mechanisms behind the liverwort-endophyte interactions observed in the laboratory, the researchers will sequence the transcriptomes of the plant and selected fungi when grown alone and together. Four fungi will be used: a growth-enhancing fungus, a detrimental fungus, and close relatives of each which show a neutral interaction. Comparing the levels of gene expression between the treatments and controls will allow the researcher to form hypotheses about which cellular systems may be important in controlling the observed interactions.

植物是自然生态系统的重要组成部分，为其他生物提供栖息地，并影响土壤和大气的组成。真菌虽然不那么引人注目，但除了分解死物质之外，还显着影响活植物的成功。生活在健康植物体内的真菌，称为真菌内生菌（以下简称内生菌），可以通过多种方式使植物受益，包括促进生长、增强抗病性以及增强对干旱等极端条件的恢复能力。因此，了解内生菌如何与其寄主植物相互作用对于管理野生生态系统以及提高林业和农业生产力（因为植物应对气候变化中的极端天气）至关重要。迄今为止，在几乎所有采样的植物中都发现了内生菌，但对其功能背后的机制的直接研究很少。该项目研究地钱内生菌的多样性和功能。该项目将对模型地钱（地钱）内生菌的多样性进行采样，并研究影响这种多样性的因素。地钱在实验室中生长良好，因此本项目将直接测试单个内生菌的效果。使用遗传方法，研究人员将确定观察到的相互作用背后的可能机制。此外，该项目开发的研究系统将为植物与内生菌相互作用研究提供许多未来的机会。研究人员将从美国各地的十个种群收集地钱植物，并表征地钱及其内生菌的多样性。将使用限制性位点相关 DNA 测序 (RAD-seq) 对整个基因组中的位点进行评估，以评估地钱基因型。通过对整个多形植物进行表面灭菌，提取总 DNA，然后对真菌条形码基因区域进行扩增和测序，对内部真菌多样性进行取样。研究人员将测试真菌群落多样性和组成、宿主基因型和种群位置之间的相关性。 这些数据将为之前在实验室生长测定中测试培养的内生菌对多形菌的影响的实验提供生态背景。为了研究实验室观察到的地钱与内生菌相互作用背后的机制，研究人员将对单独和一起生长的植物和选定真菌的转录组进行测序。将使用四种真菌：一种促进生长的真菌、一种有害的真菌以及每种真菌的近亲，它们表现出中性的相互作用。比较处理组和对照组之间的基因表达水平将使研究人员能够形成关于哪些细胞系统可能对控制观察到的相互作用很重要的假设。