Isolation and characterization of subcellular organelles from young and mature leaves of olive tree.

Subcellular organelles from young and mature leaves of olive tree have been isolated by differential centrifugation of leaf homogenates, and further purified by sucrose gradient centrifugation. Chlorophyll content was used for detecting chloroplasts after both the differential and density gradient centrifugation; aricase and catalase activities for peroxisomal identification, and the antimycin A sensitive and the antimycin-insensitive NADH-cytochrome C reductase as enzyme markers for mitochondria and microsomes, respectively. Chloroplast and mitochondrial respiration were tested polarographically by measuring the oxygen evolved or consumed, respectively, in the noncyclic electron transport chain of photosynthesis with an electron acceptor, and in the respiratory chain when succinate was used as substrate. No remarkable differences were observed between organelles from young and mature leaves, suggesting that the former can be used as a suitable material to study the lipidic biosynthetic pathways of this plant.