Destroys radicals which are normally produced within the cells and which are toxic to biological systems. 2 H(+) + 2 superoxide = H2O2 + O2 Binds 1 copper ion per subunit. Binds 1 zinc ion per subunit. Homodimer. Interacts with DJ1A and CCS. Expressed in leaves (at protein level). The spatial localization is regulated by miR398-mediated silencing. Mostly present in flowers, old rosette leaves and inflorescence, and, to a lower extent, in cauline leaves, stems and roots. Upon photosynthetically active radiation (PAR) (e.g. light fluence) increase and UV-B treatment. Accumulates in response to ozone fumigation. Induced in response to oxidative stress, via a reduction of miR398-mediated silencing. Repressed by sucrose in a miR398-mediated silencing-dependent manner. Induced by salt stress. Belongs to the Cu-Zn superoxide dismutase family.