Several fungal endophytes (C. protuberata, F. culmorum, and C. magna) confer stress tolerance to plants in the presence of certain pressures. This relationship is known as habitat-adapted symbiosis; its mechanism is currently unknown. Here, sFTIR, FTIR coupled to an FPA detector, and Raman spectromicroscopy are used to examine whether any biochemical differences exist between different isolates of the same species: one that can confer stress tolerance to plants and the other that cannot. No major differences have been observed in spectra that can differentiate between those endophytes that confer stress tolerance and those that do not. However, some hy-phae from both isolates of C. protuberata have been found to contain mannitol; its pres-ence may be more common in geothermal rather than non-geothermal isolates. Mannitol is a compound involved in providing stress tolerance to fungi. Any role that it may have in the mechanism of habitat-adapted symbiosis will need further investigation.

Several fungal endophytes (C. protuberata, F. culmorum, and C. magna) confer stress tolerance to plants in the presence of certain pressures. This relationship is known as habitat-adapted symbiosis; its mechanism is currently unknown. Here, sFTIR, FTIR coupled to an FPA detector, and Raman spectromicroscopy are used to examine whether any biochemical differences exist between different isolates of the same species: one that can confer stress tolerance to plants and the other that cannot. No major differences have been observed in spectra that can differentiate between those endophytes that confer stress tolerance and those that do not. However, some hy-phae from both isolates of C. protuberata have been found to contain mannitol; its pres-ence may be more common in geothermal rather than non-geothermal isolates. Mannitol is a compound involved in providing stress tolerance to fungi. Any role that it may have in the mechanism of habitat-adapted symbiosis will need further investigation.