Who is controlling whom within the ectomycorrhizal symbiosis : insights from genomic and functional analyses

Water cleansing, control of flooding, protection against soil erosion and desertification, maintenance of biodiversity, and carbon sequestration are amongst the main ecological services provided by forest ecosystems. Industrially, forests provide a renewable resource of wood for a wide variety of applications, from cabinetry to energy production. Given the long lifespan of forest trees, productivity in these environments is often limited by the amount of bioavailable phosphorus, nitrogen, and micronutrients. As an adaptation to this nutrient limitation, many forest trees have evolved mutualistic symbioses with soil ectomycorrhizal (ECM) fungi that contribute to their phosphorus and nitrogen nutrition (Smith and Read, 2008).