Cell-wall composition and polysaccharide synthase activity changes following photoinduction in Trichoderma viride.
The differentiation and metabolism in the soil-borne saprophytic deuteromycete Trichoderma viride are subject to control by light. We have investigated the effect of illumination of mycelia on the activities of cell-wall synthesizing enzymes beta-1,3-glucan synthase and chitin synthase and on the composition of cell alls. After 10 min illumination of dark-grown mycelia with white fluorescent light at 600 1x, a gradual rise in specific activity of membrane-bound enzymes beta-1,3-glucan synthase by about 130% and a decrease in specific activity of chitin synthase by about 50% in relation to the dark control were observed. The changes in enzyme activities were caused by de novo synthesis of corresponding polysaccharide synthases(s) and/or their regulatory components since they were not observed when protein synthesis was blocked with 50 microg/ml cycloheximide. The content of beta-1,3-glucan in the cell walls of illuminated mycelia has increased by 35-50% in comparison to the dark control while the content of chitin remained practically unchanged.
Nemcovie
M
M
Institute of Chemistry, Slovak Academy of Sciences, Bratislava.
Farkas
V
V
D002473:Cell Wall / Q000737:chemistry*; D002686:Chitin / Q000032:analysis; D002687:Chitin Synthase / Q000378:metabolism; D005936:Glucans / Q000032:analysis; D005964:Glucosyltransferases / Q000378:metabolism*; D008565:Membrane Proteins; D009024:Morphogenesis; D029702:Schizosaccharomyces pombe Proteins; D014242:Trichoderma / Q000378:metabolism / Q000528:radiation effects*
D005936:Glucans; D008565:Membrane Proteins; D029702:Schizosaccharomyces pombe Proteins; D002686:Chitin; D005964:Glucosyltransferases; D002687:Chitin Synthase; C020570:1,3-beta-glucan synthase