Iron Deficiency Promotes the Lack of Photosynthetic Cytochrome and Affects the Binding of the Luminal Extrinsic Subunits to Photosystem II in the Diatom .

In the diatom , iron limitation promotes a decrease in the content of photosystem II, as determined by measurements of oxygen-evolving activity, thermoluminescence, chlorophyll fluorescence analyses and protein quantification methods. Thermoluminescence experiments also indicate that iron limitation induces subtle changes in the energetics of the recombination reaction between reduced Q and the S/S states of the water-splitting machinery. However, electron transfer from Q to Q, involving non-heme iron, seems not to be significantly inhibited.

Characterization of TrxC, an Atypical Thioredoxin Exclusively Present in Cyanobacteria.

Cyanobacteria form a diverse group of oxygenic photosynthetic prokaryotes considered to be the antecessor of plant chloroplast. They contain four different thioredoxins isoforms, three of them corresponding to , and type present in plant chloroplast, while the fourth one (named TrxC) is exclusively found in cyanobacteria. TrxC has a modified active site (WCGLC) instead of the canonical (WCGPC) present in most thioredoxins.

Chloroplast Damage Induced by the Inhibition of Fatty Acid Synthesis Triggers Autophagy in Chlamydomonas.

Fatty acids are synthesized in the stroma of plant and algal chloroplasts by the fatty acid synthase complex. Newly synthesized fatty acids are then used to generate plastidial lipids that are essential for chloroplast structure and function. Here, we show that inhibition of fatty acid synthesis in the model alga activates autophagy, a highly conserved catabolic process by which cells degrade intracellular material under adverse conditions to maintain cell homeostasis.

Monitoring Autophagy in the Model Green Microalga Chlamydomonas reinhardtii.

Autophagy is an intracellular catabolic system that delivers cytoplasmic constituents and organelles in the vacuole. This degradative process is mediated by a group of proteins coded by autophagy-related () genes that are widely conserved from yeasts to plants and mammals. Homologs of genes have been also identified in algal genomes including the unicellular model green alga .