Search results for "Plasmolysis"
showing 3 items of 3 documents
Vesicle formation in the membrane of onion cells (Allium cepa) during rapid osmotic dehydration
2009
BACKGROUND AND AIMS Optimization of osmotic dehydration in different plant cells has been investigated through the variation of parameters such as the nature of the sugar used, the concentration of osmotic solutions and the processing time. In micro-organisms such as the yeast, Saccharomyces cerevisiae, the exposure of a cell to a slow increase in osmotic pressure preserves cell viability after rehydration, while sudden dehydration involves a lower rate of cell viability, which could be due to membrane vesiculation. The aim of this work is to study cytoplasmic vesicle formation in onion epidermal cells (Allium cepa) as a function of the kinetics of osmotic pressure variation in the external…
Ultrastructural changes of sparkling wine lees during long-term aging in real enological conditions.
2012
Ultrastructural changes of lees of three series of sparkling wines produced using the traditional method during long-term aging (4 years) were assessed by high-pressure freezing in combination with transmission electron microscopy. The stratified structure of the cell wall disappeared throughout aging. After 18 months, the microfibrous material of the cell wall appeared more diffuse and the amorphous midzone of the inner wall layer was progressively degraded. From 30 months onward, the cell wall consisted of a tangled structure of fibers. In spite of these changes, the cell wall of yeasts remained unbroken at 48 months of wine aging. Cell membrane breakage was observed for the first time in…
Desiccation and osmotic stress increase the abundance of mRNA of the tonoplast aquaporin BobTIP26-1 in cauliflower cells.
1999
Changes in vacuolar structure and the expression at the RNA level of a tonoplast aquaporin (BobTIP26-1) were examined in cauliflower (Brassicaoleracea L. var. botrytis) under water-stress conditions. Gradual drying out of slices of cauliflower floret tissue caused its collapse, with a shrinkage in tissue and cell volumes and an apparent vesiculation of the central vacuole, whereas osmotic stress resulted in plasmolysis with a collapse of the cytoplasm and the central vacuole within. Osmotic stress caused a rapid and substantial increase in BobTIP26 mRNA in slices of floret tissue. Exposure of tissue slices to a regime of desiccation showed a slower but equally large rise in BobTIP26 mRNA fo…