The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis

By Francis Martin, A. Aerts, D. Ahrén, A. Brun, Etienne G. J. Danchin, Martín, F. Aerts, A. Ahren, D. Brun, Antoine Danchin and 62 more. Nature, 2008

1,048 citations recorded by the source corpus.

Mycorrhizal symbioses—the union of roots and soil fungi—are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants. Boreal, temperate and montane forests all depend on ectomycorrhizae. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains ∼20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are fundamental to sustainable plant productivity.

Subfields: Pharmacology, Plant Science

View Paper: https://www.semanticscholar.org/paper/57edcd4927dd95c1626a3c0eab534376c9879894

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Pharmacology

In Plant Science

Citations in the corpus

Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi (2014, neutral): “Appl Environ Microbiol 62(4):1151–1158.”
Hidden fungi, emergent properties: endophytes and microbiomes. (2011, background): “It is providing new insights about the role of plant microbiomes in plant adaptation, evolution, and response to global climate change (81, 102).”
Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis (2010, background): “…of T. melanosporum might be a product of selection for specialization; this is because genome expansion, as observed in L. bicolor , is probably driven by selection on the symbiont to exploit a diversity of encountered substrates provided by multiple potential hosts and by their diverse soils 4,5 .”
The Paleozoic Origin of Enzymatic Lignin Decomposition Reconstructed from 31 Fungal Genomes (2012, background): “bicolor transcripts up-regulated in ectomycorrhizae (based on NimbleGen array profiling (37)), 884 have no homolog in the investigated brown- and white rots (Fig.”