Let us talk about three new things I didn't know till now. Hope it will be informative or useful for your entrance exams.
1. Dichanthelium lanuginosum is grass plant known as Panic grass* and was able to survive intermittent high temperatures in geothermal soils (up to 65 °C.) of Yellowstone National Park, USA.
2. In 2007 it was found that the heat tolerance is conferred to the grass due to its association with an endophytic fungus, Curvularia protuberata.
3. "Thermal Tolerance" trait conferred by the endophytic fungus is actually due to a specific RNA virus onboard. This dsRNA virus is aptly named "Curvularia thermal tolerance virus" (CThTV). Infected fungal mycelia contain two viral dsRNA molecules: a 2.2 kb dsRNA molecule that encodes two ORFs related to viral replication and a 1.8 kb dsRNA molecule with two ORFs with no similarity to any protein of known function.
As we all know virus is pathogenic. CThTV is Symbiotic.
This is an example of a tritrophic interaction, as three organisms are interacting.
Work is continuing to determine the mechanism by which the uncharacterized ORFs within the 1.8 dsRNA of CThTV confer the thermal tolerance in this fungal-plant mutualism.*Panic grass, incidentally, has nothing to do with botanical phobias; instead, the name derives from the Latin panicum, referring to foxtail millet.
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