A virus in a fungus in a plant: This three-way symbiosis was discovered in a tropical panic grass Dichanthelium lanuginosum. Marilyn J. Roossnick of the Samuel Roberts Noble Foundation in Ardmore, Okla., and collaborators were examining an endophytic fungus, Curvularia protuberata, which inhabits the roots of the grass, allowing it to grow in the high-temperature soils of Yellowstone National Park. They isolated a dsRNA virus in the fungus necessary to maintain the high-temperature tolerance.
In Faculty of 1000, Heitman writes: "Earlier studies have revealed that symbiosis between a fungus and a plant enabled the two to survive growth at temperature extremes as high as 65°C. This study reveals a third partner in this ménage à trois symbiosis, a fungal virus dubbed the Curvularia thermal tolerance virus (CThTV), [which] is necessary for the fungus to confer thermal tolerance.
"Isolates cured ...