Type II peroxiredoxin C, a member of the peroxiredoxin family of Arabidopsis thaliana: its expression and activity in comparison with other peroxiredoxins

Plants express a set of peroxiredoxins (PRX) in a cell-, development- and stress-specific manner. In the genomic database of Arabidopsis thaliana, 10 putative prx genes were identified and could be ordered in the four subgroups: the 1-Cys prx, the 2-Cys prx, prx Q and type II prx. Based on sequence analysis, four PRX proteins appear to be targeted to the chloroplast, one PRX each to the nucleus and mitochondria, respectively. The other PRX proteins contain no apparent targeting address. The paper describes the features of the Arabidopsis PRX proteins and their putative function in plant cellular antioxidant metabolism. The expression of seven prx genes was compared with RT-PCR in dependence of leaf age and salinity stress. Emphasis is placed on the type II PRX C, which is shown to be highly active in decomposing H2O2 when investigated as heterologously expressed protein.