FURTHER CHARACTERIZATION OF THE ENZYME-SYSTEM PRODUCING ALDEHYDES-C-6 FROM UNSATURATED-C-18 FATTY-ACID IN TEA CHLOROPLASTS

When C8-aldehydes (cis-3-hexenal, trans-2-hexenal and n-hexanal) were produced from C18-unsaturated fatty acids by the chloroplast lamellae as an enzyme source, oxygen which may act in singlet state is required. Light illumination, CCCP and DCMU gave no effect on the enzyme activity, though the enzyme system was localized in chloroplasts: It was likely that galactolipids and/or phospholipids played an important role in exhibiting a stable and maximal enzyme activity because of the significant decrease in the activity after the treatment of tea chloroplasts with potato lipolytic acyl hydrolase. The activity of the enzyme system was also inhibited by DCIP, MB, PMS, NTB, SKF 525-A and cytochrome c. These results suggest that the enzyme system in chloroplasts is different from the lipoxygenase-hydroperoxide lyase system in etiolated seedlings and fruits. © 1979 Taylor & Francis Group, LLC.