2008 Annual Science Report
University of Colorado, Boulder Reporting | JUL 2007 – JUN 2008
Origin of Multicellularity and Complex Land-Based Ecosystem
Project Summary
80-90% of all land plants have mutualistic symbiotic associations with fungi where the fungal symbionts provide increased access to essential minerals and the fungal symbionts gain fixed carbon. We are characterizing the fungal symbionts in early lineages of land plants (over 300 million years old) that have a life cycle where one phase is above ground and photosynthetic and another phase is completely underground for as long as fifteen years. This subterranean phase in these poorly understood plants is completely dependant on a set of fungal symbionts to provide a source of fixed carbon. Establishing the identity of the fungal symbionts in these diverse underground plants is fundamental to understanding the broader co-evolutionary and ecological history of plant-fungal associations across the almost 500 million year history of land plants.
Project Progress
During the 2007-2008 year significant progress has been made characterizing the ecological and evolutionary history of fungal symbionts in early land plants. A paper was published and highlighted in the journal New Phytologist and the doctoral candidate Jennifer Winther defended her thesis on this research. To date, the fungal symbionts throughout the life cycle in early land plant lineages (Lycopodiaceae, Psilotales and Ophioglossales) have been identified using sequence data. In addition to studying the fungal symbionts within early land plants, we have identified the fungal symbionts in photosynthetic neighboring plants to place our data in a larger ecological and evolutionary framework. Based on our sequence data, subterranean phases of the life cycle in these early land plant lineages obtain fixed carbon through an extensive fungal network. Additionally, our analyses have identified five new clades of fungi that form associations with subterranean plants. Furthermore, based on the diversity of fungi that we have identified, it is apparent that multiple species of fungi and multiple species of plants have independently evolved the ability to form plant-fungal associations where the fungus provides the plant with fixed carbon. Our research suggests a new framework for studying the ecology and co-evolution of plant-fungal symbioses where carbon flow between separate plants in a community is potentially widespread through shared fungal networks.
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PROJECT INVESTIGATORS:
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PROJECT MEMBERS:
William Friedman
Unspecified Role
Jennifer Winther
Unspecified Role
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RELATED OBJECTIVES:
Objective 4.2
Foundations of complex life
Objective 5.2
Co-evolution of microbial communities