Release of Fluorescent Peroxidized Lipids from Membranes in Senescing Tissue by Blebbing of Lipid-Protein Particles

摘要

Several lines of evidence indicate that peroxidation of membrane lipids is an inherent feature of ripening and senescence of plant tissues. Dhindsa and Dhindsa (1981), for example, demonstrated a correlation between lipid peroxidation and increased membrane permeability in senescing leaves. Levels of H_2O_2 and lipid hydroperoxides also increase in ripening fruit, and Frenkel (1978) has reported that ripening can be delayed by inhibiting the formation of H_2O_2. Pear (Pyrus cominunis L. var. Bartlett) and banana (Musa cavendishii L. var. Valery) fruit contain fluorescent products of lipid peroxidation that increase during natural or ethylene-induced ripening (Maguire and Haard, 1975). Senescing leaves and cotyledons also accumulate fluorescent peroxidation products (Wilhelm and Wilhelnova, 1981), and evidence shows that they are localized in membrane lipid bilayers (Pauls and Thompson, 1984).