Catalases in Plants: Gene Structure,
Properties, Regulation, and Expression
John G. Scandalios, Lingqiang Guan,
and Alexios N. Polidoros
Department of Genetics
North Carolina State University
Raleigh, North Carolina 27695-7614
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 H
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 Kolt-
zoff (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
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
1968) with the maize
catalases and has since been found to be the rule rather than the exception, as
OXYGEN AND REACTIVE OXYGEN SPECIES
During respiration, molecular oxygen accepts four electrons to produce two
molecules of H
0. However, because of spin restrictions, 0
cannot accept four
electrons at once but accepts them one at a time (Halliwell and Outteridge 1984).
Thus, during the one-electron
reduction of 0
, stable intermediates are
formed in a stepwise fashion (Fig.1).
Oxidative Stress and the Molecular Biology of Antioxidant Defenses
© 1997 Cold Spring Harbor Liboratory Press 0-87969-502-1/97 $5 + .00