Effect of a Free Radical Generating System on Thylakoid Membranes

The use of the free radical generating system Fe-EDTA/ascorbate affected thylakoids of wheat (Triticum durum DESF. cv. Ofanto) causing a reduction in the lipid and antioxidant concentrations and a lower calcium-dependent ATPase activity. Although the treatment caused a damage to thylakoid membranes, a decreased rate of electron transport to oxygen was observed. A further superoxide production decrease was found following 3-(3,4-dichloro-phenyl)-1,1-dimethylurea (DCMU) addition. In contrast, a higher electron spin resonance (ESR) signal was recorded when ferredoxin was added to thylakoids, both in presence and absence of DCMU.