Dissertation Research: Characterization of Foliar Fungal Endophyte Communities of Sequoia sempervirens and Investigation of their Symbiotic Relationship

论文研究：红杉叶内生真菌群落的特征及其共生关系的调查

• 批准号: 1011230
• 负责人: Chelsea Specht
• 金额: $ 1.44万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1011230&HistoricalAwards=false
• 关键词: Dissertation; Research; Characterization; Foliar; Fungal

Sequoia sempervirens (California's coastal redwood) is well known as the tallest tree in the world, with some individuals reaching 115 meters tall. Recent research has uncovered a unique physiological adaptation that allows these trees to deal with the stress of transporting water from the root system to upper branches of the canopy. When ground water stores are depleted during the long, dry summers, S. sempervirens is able to absorb water that condenses on its leaf surfaces during seasonal fog events. It is hypothesized that a community of fungi living on and within the leaves of S. sempervirens aid in the foliar absorption of water. The proposed research will first sample and characterize the foliar fungal community present in different parts of the redwood trees and from different areas of the coastal forests using molecular 'barcoding'. Stable isotope-labeled fog in glasshouse experiments will be used to determine if the presence of foliar fungi increases the tree?s ability to absorb water through its foliage, and if so which fungal communities found in association with S. sempervirens are the most effective at aiding water absorption. Finally, C13-labeled carbon dioxide will be used to track the possible transfer of carbon (in the form of sugars) from the host to the fungi, suggesting a symbiotic relationship between the tree and the fungal community it harbors.This research will help to characterize the microbiome of the california coastal redwood, an economically and ecologically important keystone species. Understanding the role of the fungal community in sustaining redwood trees will have important consequences for sustainable forestry practices, especially as drier summers become more common and foliar uptake via fog may play an increasingly important role in forest health. This research additionally demonstrates the important positive role that fungi can play in ecosystem dynamics. This research will be incorporated into three hands-on lesson plans for K-12 students that illustrate the hidden, microscopic diversity and complex species interactions in the natural environment around them. These lesson plans will be incorporated into the NSF funded GK-12 program "Exploring California Biodiversity" and utilized in the "Teaching MadScience" after school program held at two Middle Schools in the Berkeley, CA Public School District. The support will also result in the completion of a doctoral dissertation by a female scientist and the training of two undergraduate research apprentices in laboratory and computational techniques for studying fungal diversity and community ecology.

Sequoia sempervirens（加利福尼亚州沿海红杉）被誉为世界上最高的树，有些个体高达 115 米。最近的研究发现了一种独特的生理适应，使这些树木能够应对将水分从根系输送到树冠上部树枝的压力。当地下水储量在漫长而干燥的夏季耗尽时，S. sempervirens 能够吸收季节性雾气期间凝结在叶子表面的水。 据推测，生活在 S. sempervirens 叶子上和叶子内的真菌群落有助于叶子吸收水分。拟议的研究将首先使用分子“条形码”对红杉树不同部分和沿海森林不同区域的叶面真菌群落进行采样和表征。温室实验中的稳定同位素标记的雾将用于确定叶面真菌的存在是否增加了树木通过叶子吸收水分的能力，如果是的话，与 S. sempervirens 相关的哪些真菌群落在吸收水分方面最有效。帮助水分吸收。最后，C13 标记的二氧化碳将用于追踪碳（以糖的形式）从宿主到真菌的可能转移，这表明树木与其所拥有的真菌群落之间存在共生关系。这项研究将有助于描述了加州沿海红杉的微生物组特征，加州沿海红杉是一种具有重要经济和生态意义的关键树种。 了解真菌群落在维持红杉树方面的作用将对可持续林业实践产生重要影响，特别是随着干燥的夏季变得更加普遍，而叶面通过雾的吸收可能在森林健康中发挥越来越重要的作用。这项研究还表明真菌在生态系统动态中可以发挥重要的积极作用。这项研究将被纳入 K-12 学生的三个实践课程计划中，这些计划说明了他们周围自然环境中隐藏的微观多样性和复杂的物种相互作用。这些课程计划将纳入 NSF 资助的 GK-12 计划“探索加州生物多样性”，并在加州伯克利公立学区两所中学举办的“疯狂科学教学”课后计划中使用。该支持还将帮助一名女科学家完成博士论文，并培训两名本科生研究学徒，进行实验室和计算技术方面的培训，以研究真菌多样性和群落生态学。