The Radiation Sensitivity of Phycomyces: Interaction of Visible Light and Ionizing Radiation

Abstract

The radiation response of Phycomyces in regard to growth rate and biochemical changes was anslyzed. An interaction between visible light and ionizing raya occurs. Cultures grown under illumination differ from those grown in darkness in respect to some biochemical reactions (lactic acid concentration changes). Since the effect of ionizing radiation on the growth rate was found to be independent of whether light (dark) cultures were used, some resctions on the bioehemical level do not seem to be directly connected with the influence on the growth-rate meclumism. The lactic acid changes were used as an indication of the general radiation sensitivity of all parts of the oragnism in regard at least to this biochemical property. Analyses of cultures grown on P/sup 32/ did not support the notion that ionizing nediation causes permeability chsnges or diffusion effects within the organism. (auth)