Different mechanisms of the biochemical adaptation of mycelial fungi to temperature stress: Changes in the cytosol carbohydrate composition

The effect of temperature stress on the cytosol carbohydrate composition of fungi belonging to various systematic groups was investigated. InMucorales representatives (subkingdomEomycota, phylumArchetnycota, classZygomycetes), adaptation to hypo- and hyperthermia occurs via the regulation of trehalose synthesis, although inositol is also involved in these processes inBlakeslea trispora. InAscomycota (subkingdomNeomycota), oversynthesis of mannitol and glycerol occurs under hypothermia, whereas oversynthesis of trehalose and inositol takes place under hyperthermia.Basidiomycota (subkingdomNeomycota) use two pathways of biochemical adaptation, depending on the cytosol carbohydrate composition. In the absence of sucrose, glycerol and arabitol are involved in the adaptation to hyperthermia; trehalose accumulates under hypothermic conditions (type I of regulation). Type II regulation (revealed inPleurotus ostreatus) involves sucrose rather than glycerol or arabitol. The data obtained are discussed in terms of fungal systematics and phylogeny.