Mechanisms of plant-fungi symbiosis characterized by DOE Joint Genome...( WALNUT CREEK CA Plants gained their ...)

WALNUT CREEK, CA, Plants gained their ancestral toehold on dry land with considerable help from their fungal friends. Now, millennia later, that partnership is being exploited as a strategy to bolster biomass production for next generation biofuels. The genetic mechanism of this kind of symbiosis, which contributes to the delicate ecological balance in healthy forests, also provides insights into plant health that may enable more efficient carbon sequestration and enhanced phytoremediation, using plants to clean up environmental contaminants. These prospects stem from the genome analysis of the symbiotic fungus Laccaria bicolor, generated by the U.S. Department of Energy Joint Genome Institute (DOE JGI) and collaborators from INRA, the National Institute for Agricultural Research in Nancy, France, and published March 6 in the journal Nature. This international team effort also involved contributions from 16 institutions, including Oak Ridge National Laboratory; Ghent University, Belgium; Lund University, Sweden; Goettingen University, Germany; CNRS-Aix-Marseille University, France; Nancy University, France; and the University of Alabama, Huntsville.

Trees' ability to generate large amounts of biomass or store carbon is underpinned by their interactions with soil microbes known as mycorrhizal fungi, which excel at procuring necessary, but scarce, nutrients such as phosphate and nitrogen. Most of these nutrients are transferred to the growing tree. When Laccaria bicolor establishes a partnership with plant roots, a mycorrhizal root is created. The fungus within the root is protected from competition with other soil microbes and gains preferential access to carbohydrates within the plant. Thus, the mutualistic relationship is established.

"Forests around the world rely on the partnership between plant roots and soil fungi and the environment they create, the rhizosphere," said Eddy Rubin, DOE JGI Director. "The Laccaria genome represents a valu
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