Changes in the cytosol carbohydrate composition during the cytodifferentiation process in fungi of the order Agaricales

It was established that the disaccharide trehalose and the polyols mannitol and arabitol are the main cytosol carbohydrates of Basidiomycetes, whereas inositol is a minor component. Fungal cell differentiation is accompanied by qualitative and quantitative changes in the cytosol carbohydrate composi tion, which are species-specific and largely dependent on the cultivation t emperature dynamics. It was shown for the first time that a cold shock, whi ch triggers fruiting body formation in Lentinus edodes, causes intense arab itol synthesis, a decrease in the mannitol level, and the appearance of gly cerol. Based on these results, in conjunction with the data on the temperat ure dependence of fruiting body formation in fungi under natural conditions , we suggest that fungi contain temperature-dependent protective carbohydra tes. These include arabitol, mannitol, and glycerol under conditions of hyp othermia and trehalose, inositol, and possibly sucrose under conditions of hyperthermia. Pleurotus ostreatus basidiospores and fruiting bodies were es tablished to contain sucrose and an unidentified disaccharide. The data obt ained are discussed in terms of the Basidiomycetes taxonomy and the relatio nship between Basidiomycetes and the kingdom Planta.