Catalases in Plants: Gene Structure, Properties, Regulation, and Expression

Abstract

Catalase action in plant and animal tissues was first observed in 1818 by Thenard, who noted that such tissues readily degraded hydrogen peroxide, a substance he had also discovered some years earlier (Aebi and Sutter 1971). Loew (1901) first established that the degradation of H₂O₂ in tissues was due to the effect of an individual, separable enzyme, which he named “catalase.” Warburg (1923) suggested that catalase is an iron-containing enzyme, because it is inhibited by cyanide. Evidence for its hematin prosthetic group was presented by Zeile and Hellstrom (1930). Catalase was first purified and crystallized from beef liver, and its identity was made clear by Sumner and Dounce (1937). The earliest genetic studies on catalase were reported by the Russian biologist Koltzoff (1927), who demonstrated that blood catalase levels in several animal species are inherited and segregate according to Mendelian rules.

Catalase has been found in all plants examined, and has been most thoroughly studied biochemically, genetically, and molecularly in the agronomically important species Zea mays L. (Scandalios 1990). That catalases can exist in multiple molecular forms or isozymes encoded by multiple genes, in any organism, was first demonstrated by Scandalios (1965 Scandalios (1968) with the maize catalases and has since been found to be the rule rather than the exception, as originally perceived.

OXYGEN AND REACTIVE OXYGEN SPECIES
During respiration, molecular oxygen accepts four electrons to produce two molecules of H₂O. However, because of spin restrictions, O₂ cannot accept four electrons at once but accepts them one at a time...