[Influence of cultivation temperature on the development of functionally active photoregulatory systems in cells of Neurospora crassa and Physarum polycephalum].

Illumination with a visible light is known to induce accumulation of colored carotenoid pigments in mycelial cells on Neurospora crassa and sporulation of starved macroplasmodia of Physarum polycephalum. In both microorganisms, the temperature, at which they are cultivated in the dark, controls manifestation of the photoregulation processes in the cells subsequently exposed to light. The maximal rate of photoinduced accumulation of carotenoids in N. crassa is observed, when the cells are grown in the dark at 25-28 degrees C; the highest photoinduction of P. polycephalum sporulation takes place, if microplasmodia are grown in the dark at 21-23 degrees C and macroplasmodia are starved at no more than 23 degrees C. Both a 5 degree C rise and fall of the temperature of dark cultivation from the optimum dramatically inhibits the cell ability for photoresponse. This inhibition is not associated with suppression of cell growth processes: temperature rise at the dark period up to 32 degrees C for N. crassa and 25-27 degrees C for P. polycephalum brings the subsequent photoresponse to a minimum but does not produce any negative effect on the growth rate. It is concluded that temperature affects specifically processes of formation of functionally active photoregulatory systems.