STRUCTURE AND CHEMICAL-COMPOSITION OF THE CELL-WALLS FROM THE HAPLOIDYEAST AND MYCELIAL FORMS OF USTILAGO-MAYDIS

Ruiz-Herrera, J., Leon, C. G., Carabez-Trejo, A., and Reyes-Salinas, E . 1996, Structure and chemical composition of the cell walls from the haploid yeast and mycelial forms of Ustilago maydis, Fungal Genetics a nd Biology 20, 133-142, Isolated or in vivo cell wails from the yeast and mycelial forms of haploid Ustilago maydis were not stained by the normal osmium procedure for electron microscopy. KMnO4 stained mycelia l walls, revealing a layered structure with a loose electron-dense lay er at the cell surface, but stained only the outer surface layer of ye ast walls, Walls were purified from extracts obtained by ballistic and ultrasonic disruption, Chemical analysis showed that composition of y east and mycelial walls was similar, Yeast walls contained higher amou nts of neutral sugars and protein, whereas mycelial walls contained mo re chitin and phosphate, No chitosan or uronic acids were detected. Hi gher proportions of xylose and mannose were present in yeast walls, wh ereas the amounts of glucose and galactose were higher in mycelial wal ls, Fucose, arabinose, and ribose were detected in yeast walls only, E lectrophoretic patterns of proteins extracted with SDS, beta 1,3-gluca nase, or chitinase were similar in walls of both morphologies, althoug h some differential bands were identified, Most antigenic proteins app eared in the covalently bound fraction of the wall, Some were common t o both morphologies, but others were stage specific. (C) 1996 Academic Press, Inc.