Removal of H(2)O(2), oxidation of toxic reductants, biosynthesis and degradation of lignin, suberization, auxin catabolism, response to environmental stresses such as wounding, pathogen attack and oxidative stress. These functions might be dependent on each isozyme/isoform in each plant tissue. Suggested to catalyze the deposition of the aromatic residues of suberin on the cell wall and thus play a role in cell-suberization. 2 a phenolic donor + H2O2 = 2 a phenolic radical donor + 2 H2O Binds 2 calcium ions per subunit. Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit. Belongs to the peroxidase family. Classical plant (class III) peroxidase subfamily.