Chlorophyll and carotenoid degradation mediated by thylakoid-associated peroxidative activity in olives (Olea europaea) cv. Hojiblanca

A peroxidative activity was found in solubilized thylakoid membranes of olives (Olea europaea) cv. hojiblanca that catalyses degradation of chloroplast pigments in the presence of H2O2 and 2,4-dichlorophenol (DCP). The intermediate products of this degradation were analyzed using HPLC with diode array detection and the results indicated that 132-OH-chlorophyll a and 132-OH-chlorophyll b were the primary catabolites. The peroxidative activity assosiated with the thylakoid membranes affected, not only chlorophyll a and chlorophyll b, but also other accessory pigments in the photosynthetic process, such as the carotenoids. Quantitatively, the progressive decrease of the ratios Chl a/b and total Chls a +b/carotenoids indicated a more rapid disappearance of Chl a than of Chl b and a faster degradation of Chls a +b than of carotenoids.