Lysozyme-Induced Sensitivity of Neurospora Ascospores to Furfural

Abstract

The precise nature of the permeability barriers of plant cells has eluded analysis although their physiological effects have been exhaustively studied. Contributing most to the difficulties encountered in these studies has been the complexity of their chemical constituents and or? ganization. However, an excellent approach to this problem exists in the use of enzymes as specific reagents in the analysis of cell wall and membrane constituents. Apart from their specificity, these substances act under mild (physiological) conditions and are large enough in size so that it may be assumed that their effect would be localized on the outside of the cell. Weibull (1953) has shown that the ability of a bacterial cell to retain certain cellular constituents is greatly altered by the use of lysozyme. In addition, Tomcsik (1954) reported that prolongations of bacterial cross walls may extend into the capsule on the basis of enzymatic digestion of antibody-treated cells. With these facts in mind, studies were undertaken on the effect of enzymatic treatment upon the ascospores of Neurospora tetrasperma. These cells exist in at least two different physiological conditions, the durations of which are under the control of the investigator. Thus, in the dormant state, the cell metabolizes at a low rate, is impermeable to some poisons, and is resistant to drying and other physical treatments. Two means exist for breaking dormancy and these include heat-treatment (Goddard, 1935) and treatment with furfural and related heterocyclic compounds (Emerson, 1948; Sussman, 1953). Upon such activation a twenty to thirty-fold increase in metabolic rate ensues, accompanied by other changes in permeability and resistance to chemical and physical treatments. Using these facts as a basis, the effect of lysozyme and other enzymes upon the activation and germination of ascospores of N. tetrasperma was investigated. By this means it was hoped to learn