Peroxidases are ubiquitous enzymes found in virtually all green plants, many fungi and aerobic bacteria. The isozymic heterogeneity of peroxidases appears to result from de novo synthesis, as well as an array of physiological/ecological determinants including hormones, light, gravity, and infection. Homologies among isoperoxidases from the same species are largely distinguished by the isoelectric point and as well as by protein sequence data. The basic and acidic peroxidases from a number of angiosperms show a greater functional and structural relationship within rather than between these groups. Peroxidases have phylogenetically-correlated similarities based on the chemical nature and redox potentials of the substrates which they can oxidize. Peroxidases often increase as a response to stress, and one of the principle roles of peroxidase appears to be cellular protection from oxidative reactions imposed on all photosynthetic plants. The relationships among the peroxidases, IAA and lignification emerge as a particular adaptation of vascular plants to the land environment. The great catalytic versatility of peroxidase as its predominant character and, therefore, no single major role need necessarily exist for this multifaceted enzyme.
Sunintary. The heterogeneity of the peroxidases in peas was examined by starch gel electrophoresis. Comparisons were made between tall and dwarf ctultivars and among organ systerms developed in light and darkness. Isoperoxidase bands could be grouped as cathodic, anodic and near-neutral (at pH 9.0) types. The cathodic set stained well with guiaiacol oxidation produicts whereas some anodic bands reacted preferentially with 2,6-dimethoxyphenol. Some near-netutral bands were aceto-carmine positive and may have lbeen organellar.Each organ had a characteristic isozyme pattern, and the band patterns in corresponding organs from different varieties were far more alike than were the patterns in the different organs within each variety. Ontogenetic changes were marked in all 3 organ systems, principally in the cathodic bands. The effect of light on isozymal patterns was quantitative rather than qualitative, possibly infltuencing the isoperoxidases secondarily via its effect uipon organ physiology and development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.