Alterations in thylakoid membrane composition induced by iron starvation in sunflower plants

Previous analysis of photosynthetic electron transport of isolated thylakoi d membranes in iron-deficient sunflower plants showed a decrease in the who le chain and photosystem I (PSI) activities, whereas photosystem II (PSII) activity resulted to be unaffected (Tognini et al., 1996). On the basis of these results, the analysis of the molecular composition of thylakoid membr anes was carried out. By using immuno-blotting methods, a decrease in the p rotein content of PSI in iron-deficient plants was detected, while light-ha rvesting complex II (LHCII) increased and PSII core complex (CC) did not ch ange compared to the controls. In iron-deficient plants, the tetramethylben zidine staining of thylakoid protein gels showed a decrease in the content of cytochrome f and cytochrome b6, while cytochrome b559 remained unchanged in control and stressed plants.