ISSN 1021-4437, Russian Journal of Plant Physiology, 2008, Vol. 55, No. 5, pp. 699–705. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © M.G. Polovnikova, O.L. Voskresenskaya, 2008, published in Fiziologiya Rastenii, 2008, Vol. 55, No. 5, pp. 777–785.
In recent time, the investigation of anthropogenic
factors on plant organisms acquires an extremely
important signiﬁcance because of aggravation of eco-
logical crisis related to environment anthropogenic pol-
lution. Therefore, one of the most actual problems of
current plant ecological physiology is the monitoring of
structural and functional diversity of plants inhabiting
urbophytocenoses under conditions of ecological
In urban environment, plant defense mechanisms
are directed not only to plant surviving but also to the
realization of their developmental programs under
long-term action of pollutants. Plant developmental
state is characterized by speciﬁc features of their mor-
phogenesis and deﬁnite the ratio between the process of
new growth and dying off; at present, a speciﬁcity of
physiological and biochemical processes in the individ-
uals at different developmental stages is established .
At the same time, the action of anthropogenic factors in
the cities on plant physiology at different developmen-
tal stages is poorly studied, although such investiga-
tions are necessary for creation of the complete pattern
of plant growth and development in urbophytocenoses.
Redox processes, in particular those involving free
oxygen radicals , play a substantial role in plant
responses to unfavorable conditions. Generation of
reactive oxygen species (ROS), such as singlet oxygen
( ), superoxide radical hydroxyl radical (
and hydrogen peroxide (
), (oxidative burst) is one
of the earliest plant responses to stress . Oxygen rad-
icals and their derivatives threaten seriously the living
organisms because they could suppress enzyme activi-
ties, change nucleic acids, degrade proteins, affect
membrane permeability, etc. .
A multicomponent antioxidant system (AOS), com-
prising low- and high-molecular-weight components,
maintains a dynamic intracellular equilibrium between
Activities of Antioxidant System Components
and Polyphenol Oxidase in Ontogeny of Lawn
Grasses under Megapolis Conditions
M. G. Polovnikova and O. L. Voskresenskaya
Department of Ecology, Faculty of Biology and Chemistry, Mari State University,
ul. Osipenko 60, Ioshkar-Ola, 424002 Russia;
fax: 7 (8362) 56-5781; e-mail: email@example.com
Received July 3, 2007
—The activities of antioxidants enzymes (peroxidase (POX) and catalase (CAT)), the contents of non-
enzymatic antioxidants (vitamin C, carotenoids), and the activity of polyphenol oxidase (PPO) were studied in
vegetative organs of red clover (
L.) and meadow-fescue (
under city conditions. The plants of three ages (virginal (V), generative (G), and subsenyl (SS)) were analyzed.
The highest POX and PPO activities were characteristic of G plants, whereas CAT was most active in V plants.
The content of low-molecular-weight antioxidants depended on species speciﬁcity and developmental stage and
also on environment pollution. The content of ascorbate (vitamin C) declined linearly with plant development.
Medium pollution also reduced the ascorbate content in tested plant leaves and roots. In contrast, the content of
carotenoids increased with the increased activity of anthropogenic factors. The highest content of the pigments
was in G plants. At all developmental stages and in all habitats, meadow-fescue (tolerant species) was charac-
terized by the lower content of studied compounds than red clover (sensitive species). Thus, anthropogenic
medium pollution resulted in the peroxide group accumulation, POX and PPO activation, carotenoid accumu-
lation, and the ascorbate content decline in the vegetative tissues during the entire ontogeny of tolerant and sen-
sitive lawn plants.
Key words: Trifolium pratense - Festuca pratensis - ontogeny - pollution - peroxidase - catalase - polyphenol
oxidase - ascorbate - carotenoids
: AOS—antioxidant system; CAT—catalase; G—
generative plants; POX—peroxidase; PPO—polyphenol oxi-
dase; ROS—reactive oxygen species; SDL—safe dose limit;
SOD—superoxide desmutase; SS—subsenyl plants; V—virginal