Articles
CHANGES IN PHYSICAL PROPERTIES OF CELL MEMBRANES AND THEIR ROLE IN SENESCENCE OF ROSE FLOWER PETALS
Article number
181_49
Pages
371 – 376
Language
Abstract
The mechanisms which lead to, and regulate, senescence were studied in rose flower petals (Rosa hyb.
L.). The changes which occur in properties of cell membranes during senescence were measured and the role of ethylene in regulating these changes determined.
During initial aging of cut flowers there were marked changes in physical properties of microsomal membrane lipids: increased microviscosity, increase in the gel to liquid-crystalline phase-transition temperature, appearance of ordered gel phase lipid in the otherwise liquid-crystalline membrane lipids, and lipid phase separation.
Lipid phase separation leads to increased membrane permeability to ions, which leads in turn to overt signs of senescence, petal wilting and blueing.
The increase in membrane lipid microviscosity was the result of formation of certain neutral lipids in membranes during aging.
Ethylene regulated senescence, at least in part, by causing the rise in lipid phase-transition temperature.
Silver thiosulphate, an inhibitor of ethylene synthesis and action, inhibited the natural increase in both.
It is concluded that changes in physical properties of membrane lipids play a critical role in regulation of senescence in rose petals and that ethylene regulates senescence via these changes.
L.). The changes which occur in properties of cell membranes during senescence were measured and the role of ethylene in regulating these changes determined.
During initial aging of cut flowers there were marked changes in physical properties of microsomal membrane lipids: increased microviscosity, increase in the gel to liquid-crystalline phase-transition temperature, appearance of ordered gel phase lipid in the otherwise liquid-crystalline membrane lipids, and lipid phase separation.
Lipid phase separation leads to increased membrane permeability to ions, which leads in turn to overt signs of senescence, petal wilting and blueing.
The increase in membrane lipid microviscosity was the result of formation of certain neutral lipids in membranes during aging.
Ethylene regulated senescence, at least in part, by causing the rise in lipid phase-transition temperature.
Silver thiosulphate, an inhibitor of ethylene synthesis and action, inhibited the natural increase in both.
It is concluded that changes in physical properties of membrane lipids play a critical role in regulation of senescence in rose petals and that ethylene regulates senescence via these changes.
Authors
John D. Faragher, S. Mayak, Ellen J. Wachtel
Keywords
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