Identification of Zantedeschia aethiopica Cat1 and Cat2 catalase genes and their expression analysis during spathe senescence and regreening

Plants encode catalase (CAT; EC 1.11.1.6) as multigene families, which may reflect the multiple and diverse roles played by this enzyme. Catalases from higher plants can be subdivided into three distinct types, according to their phylogenetic relationship. However, there is not a specific correlation of phylogeny and function within these groups, as catalases from the same type can play different specific roles. We report on the characterization of two monocot catalase genes from Zantedeschia aethiopica (a C-3-tYpe Araceae) and its expression analysis during spathe senescence and regreening. Z. aethiopica CAT2 appears to play an exclusive role in scavenging photorespiratory H2O2, but is more phylogenctically related to the unspecific Zea mays CAT3 and Oryza sativa CATA than to the photorespiratory-related Zea mays CAT2 and Onyza sativa CATC. Z aethiopica CAT1 is more phylogenetically related to Zea mays CAT1 and Oryza sativa CATB and appears to have a dual role in scavenging glyoxysomal and peroxisomal H2O2. (C) 2004 Elsevier Ireland Ltd. All rights reserved.