Changes in the Physical State of Membrane Lipids during Senescence of Rose Petals 1
AUTOR(ES)
Faragher, John D.
RESUMO
Changes in the physical state of microsomal membrane lipids during senescence of rose flower petals (Rosa hyb. L. cv Mercedes) were measured by x-ray diffraction analysis. During senescence of cut flowers held at 22°C, lipid in the ordered, gel phase appeared in the otherwise disordered, liquid-crystalline phase lipids of the membranes. This was due to an increase in the phase transition temperature of the lipids. The proportion of gel phase in the membrane lipids of 2-day-old flowers was estimated as about 20% at 22°C. Ethylene may be responsible, at least in part, for the increase in lipid transition temperature during senescence since aminooxyacetic acid and silver thiosulfate inhibited the rise in transition temperature. When flowers were stored at 3°C for 10 to 17 days and then transferrd to 22°C, gel phase lipid appeared in membranes earlier than in freshly cut flowers. This advanced senescence was the result of aging at 3°C, indicated by increases in membrane lipid transition temperature and ethylene production rate during the time at 3°C. It is concluded that changes in the physical state of membrane lipids are an integral part of senescence of rose petals, that they are caused, at least in part, by ethylene action and that they are responsible, at least in part, for the increase in membrane permeability which precedes flower death.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1056497Documentos Relacionados
- Deuterium Magnetic Resonance Studies of Senescence-Related Changes in the Physical Properties of Rose Petal Membrane Lipids.
- Cytokinin Activity in Rose Petals and Its Relation to Senescence 1
- Respiration of Developing Rose Petals. 1
- Changes in composition, biosynthesis, and physical state of membrane lipids occurring upon aging of Mycoplasma hominis cultures.
- Senescence-Related Changes in ATP-Dependent Uptake of Calcium into Microsomal Vesicles from Carnation Petals 1