Plant peroxidases, specifically class III peroxidases, are present in all land plants and belong to a large multigenic family. These enzymes are involved in a wide range of physiological processes throughout the plant's life cycle, from germination to senescence. They can generate reactive oxygen species (ROS) through both peroxidative and hydroxyl cycles, which they use to modulate cell wall compounds, regulate H₂O₂ levels, and respond to internal and external stimuli. The high number of isoforms and their heterogeneous regulation contribute to their multifunctional roles, such as building and loosening cell walls, defending against stress, and facilitating symbiosis. The review discusses the factors influencing the delicate balance of these functions, highlighting the evolution and conservation of peroxidase genes and their diverse roles in plant development and defense.Plant peroxidases, specifically class III peroxidases, are present in all land plants and belong to a large multigenic family. These enzymes are involved in a wide range of physiological processes throughout the plant's life cycle, from germination to senescence. They can generate reactive oxygen species (ROS) through both peroxidative and hydroxyl cycles, which they use to modulate cell wall compounds, regulate H₂O₂ levels, and respond to internal and external stimuli. The high number of isoforms and their heterogeneous regulation contribute to their multifunctional roles, such as building and loosening cell walls, defending against stress, and facilitating symbiosis. The review discusses the factors influencing the delicate balance of these functions, highlighting the evolution and conservation of peroxidase genes and their diverse roles in plant development and defense.