Effect of hydrostatic pressure on the morphology and ultrastructure of wild-type and trehalose synthase mutant cells of Saccharomyces cerevisiae

Aims: Saccharomyces cerevisiae was used for studying the physiological effe cts of hydrostatic pressure. Methods and Results: The effects of hydrostatic pressure on the ultrastruct ure of wild-type and trehalose-6-phosphate synthase (tps1) mutant cells wer e investigated by transmission electron microscopy. Pressure induced severa l morphological changes in wild-type and tps1 cells, the latter showing gre ater structural alterations. When the cells were submitted to a preheat tre atment they both acquired resistance to the pressure treatment. Conclusions: As the tps1 mutant was 1000-fold more barosensitive than its p arental strain, it showed greater structural alterations compared with the wild-type. Microscopic images of the yeast cells suggested that hydrostatic pressure induced changes in the cytoskeleton and therefore, on the cell wa ll and in the dynamics of the organelles. Significance and Impact of the Study: This work presents the effects of hyd rostatic pressure on the morphology of yeast cells and confirms the importa nce of several different factors in the protection of cells against stress.