Archive for August, 2011

Fair Trade Underground

August 21st, 2011

The findings by Kiers and Bücking’s groups, published this week in Science, point to a fair trade between plants and their associated arbuscular mycorrhizal fungi (AMF). It appears that the widely accepted view that the host plant controls the symbiosis is too simplistic. Both partners play a key role in the nutrient exchange so important in this mutualistic symbiosis: “plants can detect, discriminate, and reward the best fungal partners with more carbohydrates. In turn, their fungal partners enforce cooperation by increasing nutrient transfer only to those roots providing more carbohydrates.”

Kiers et al. (2011) Reciprocal rewards stabilize cooperation in the mycorrhizal symbiosis. Sciencedoi:10.1126/science.1208473.

Read more …

Selosse MA, Rousset F (2011) The Plant-Fungal Marketplace. Science 333, 828-829.

Fair Trade at Plant Roots: Plant and fungal symbionts swap more resources with partners that provide a greater return of nutrients. The Scientist

(A) Glomeromycete fungi produce structures called arbuscules within root cells to exchange nutrients. Inset photo shows roots of Allium porrum colonized by Glomus mosseae. (B) The symbiotic benefits include reciprocal nutrient exchange and protection against abiotic and biotic stress in the soil environment. Credit: B. Strauch (Science).

1st Mycorrhizal Genomics Workshop

August 21st, 2011

We are organizing the 1st Mycorrhizal Genomics Workshop at the INRA center in Champenoux (France), on September 28-29, 2011. The aim of the workshop is (1) to establish the current status of the JGI CSP  ‘25 Mycorrhizal Genomes‘ project, (2) to train people to use the JGI annotation tools, and (3) to bring together future annotators for discussing the data sets which will be generated by machine annotations and manual curations. The format of the workshop will be roughly equally split between informal presentations (summarizing the current findings), what we hope will be spirited discussion and brainstorming about how to take advantage of the genome sequences to inform our understanding of symbiosis and fungal biology.

A group of six mycorrhizal species have been selected for the first analyses. These include:

  • the unpublished Laccaria bicolor v2.0,
  • the annotated unpublished Paxillus involutus (Boletales) (thanks to Anders Tunlid),
  • Oidiodendron maius (Leotiomycetes): assembly and automated annotation done, RNA-Seq ESTs are available,
  • Hebeloma cylindrosporum (Agaricales, Cortinariaceae): assembly done, annotation on-going, RNA-Seq ESTs are available,
  • Pisolithus microcarpus (Boletales): assembly done, RNA-Seq ESTs are available,
  • Piloderma croceum (Atheliales): assembly on-going, RNA-Seq on-going.

Thanks to David Hibbett, these genomes will be compared to the current set of yet unpublished genomes of >15 saprotrophic agaricomycotina.

Seven additional mycorrhizal species are in the scope of work for 2011 from JGI: Cenococcum geophilum, Sebacina vermifera, Suillus luteus, Scleroderma citrinum, Terfezia boudieri, Tulasnella calospora, and Tricholoma matsutake. gDNA preps have either been shipped to JGI or are on-going in our lab.

The rest of the Tier 1 and Tier 2 species are on hold until we are able to extract enough DNA of the requested quality (Amanita muscaria, Boletus edulis, Lactarius quietus, Meliniomyces spp., Paxillus rubicundulus, Rhizoscyphus ericeae, Tomentella sublilacina) or find the culture for growing the mycelium (Cantharellus cibarius, Coltricia cinnamomea, Gymnomyces xanthosporus, Ramaria formosa).

Photo: The Aspen/Fly Agaric ectomycorrhizal symbiosis.  The fruiting body of the symbiotic Amanita muscaria is produced by the underground mycelium associated to its host-plant, a small aspen seedling. MSA Mushroom Forey, Large Animal Research Station, University of Fairbanks, AK (© F Martin).


myTree of the Month

August 21st, 2011

Western hemlocks (Tsuga heterophylla) colonizing a rocky islet of the Chiswell Islands in the Alaska Maritime National Wildlife Refuge (Kenai Peninsula, Alaska). Western hemlock is native to the west coast of North America, with its northwestern limit on the Kenai Peninsula. Cruising between the Chiswell Islands is an once-in-a-lifetime experience.

Photo: © F Martin

Alaskan Rainforest

August 21st, 2011

‘Tout est vert, en haut, en bas, partout. Même la lumière tamisée par les hautes frondaisons participe à ce camaïeu qui va de l’émeraude au céladon. Arbres, pierres, souches, sentier sont recouverts d’une mousse épaisse et gorgée de pluie. L’endroit est saturée d’eau, qui sourd et goutte de partout ; le moindre trou se remplit en quelques secondes. Pas un chant d’oiseau, la forêt est muette, le silence ouaté.” Stéphane Jarno (Télérama,3212-3213).

Photos: Alaska rainforest at Tonsina Point, Seward, Kenai Peninsula, Alaska (© F Martin).