ISSN 10214437, Russian Journal of Plant Physiology, 2011, Vol. 58, No. 2, pp. 210–217. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © E.V. Pradedova, O.D. Isheeva, R.K. Salyaev, 2011, published in Fiziologiya Rastenii, 2011, Vol. 58, No. 2, pp. 177–185.
In recent years, a hypothesis, according to which
the cause for the oxidative stress is a disturbance in the
balance between ROS generation and elimination
rather than the intense ROS generation per se,
becomes increasingly popular . It is suggested that
the main reason for oxidative stress could be the failure
of defense systems. The systems of the antioxidant
defense counteract the damaging ROS effects. The
main components of these systems are antioxidants
(AO). This term was initially applied to compounds
inhibiting free radical oxidation (FRO) . Later, the
application of the terms “antioxidant system” and
“antioxidants” was widened, especially in the biologi
cal literature [2, 3]. Thus, currently it is often implied
that the AO defense system includes not only the sys
tems eliminating ROS and preventing their generation
but also the systems of detoxification, e.g., eliminating
compounds damaged due to their spontaneous oxida
tion by oxygen. Another definition of AO is also met:
AO are natural or synthetic substances retarding or
preventing oxidation of organic compounds .
Among them are substances capable of neutralization
of free radicals and suppression of FRO and also those
protecting biological structures [1–4].
To provide for the most efficient defense, all ele
ments of the system, i.e., antioxidants, are located in
different subcellular structures . In spite of a sub
stantial progress made in the understanding functions
of particular or local components of the AO defense, a
complex intracellular net of differently compartmen
tated AO hampers the understanding the system func
tioning as a whole. Classification of the antioxidant
system helps much in the development of a general
notion about functioning of the intracellular antioxi
dant net. On the basis of reasonable classification of
the system components, taking into account the spec
ificity of their structure, function, localization, and
interaction, more purposeful and efficient studying of
defense against unfavorable factors accompanied by
ROS generation becomes possible.
PRINCIPLES OF ANTIOXIDANT DEFENSE
The classification system, taking into account AO
specific features, needs in definite grounds. The
unique principles of classification of the AO defense
systems are not yet elaborated and demand a compre
hensive examination. Therefore, until now there is no
universal classification of these systems but there are
Classification of the Antioxidant Defense System
as the Ground for Reasonable Organization
of Experimental Studies of the Oxidative Stress in Plants
E. V. Pradedova, O. D. Isheeva, and R. K. Salyaev
Siberian Institute of Plant Physiology and Biochemistry, Siberian Division, Russian Academy of Sciences,
ul. Lermontova 132, 664033 Irkutsk, Russia;
fax: 7 (3952) 510754; email: firstname.lastname@example.org
Received May, 24, 2010
—A specialized system for antioxidant defense prevents damaging effects of reactive oxygen species
(ROS) in the cells of plants and other organisms. The components of this system are numerous and diverse.
Repeated attempts were taken to classify these components, which, however, did not result in the creation of
unique and commonly accepted classification. In the last few decades, a great body of information concern
ing antioxidants (AO) has been accumulated, and it demands classification. Today this demand is especially
urgent: such classification of the system of AO defense would generalize and systematize the available knowl
edge of AO and the system of AO defense as a whole and also helps in more efficient and purposeful studying
the mechanisms of organism defense against unfavorable factors accompanied by ROS generation. This
review discusses the purposeful of the reasonable classification of the AO defense system; we present several
examples of current classifications and suggest our resolution of this problem.
: plants, antioxidants, the system of antioxidant defense and its classification.
: AA—ascorbic acid; AO—antioxidants; FRO—
free radical oxidation; GPO—glutathione peroxidase; GSH—
glutathione reduced; GST—glutathione Stransferase; MDAR—
monodehydroascorbate reductase; SOD—superoxide dismutase.