ISSN 1021-4437, Russian Journal of Plant Physiology, 2009, Vol. 56, No. 5, pp. 686–694. © Pleiades Publishing, Ltd., 2009.
Published in Russian in Fiziologiya Rastenii, 2009, Vol. 56, No. 5, pp. 759–767.
Cadmium is one of the major environmental con-
taminants in water bodies . It originates from natural
(weathering of rocks) or anthropogenic sources (indus-
trial efﬂuent, agricultural run-offs) . Numerous stud-
ies have shown that Cd in plants might cause leaf-roll,
chlorosis, damage to the light-harvesting complex and
photosystems and reduction of the chlorophyll biosyn-
thesis. The role of submerged plants in relation with the
accumulation of metals and its toxicity has been well
documented among aquatic macrophytes [3–6]. How-
ever, the absorptive capacities are species speciﬁc and
dependent on the growth rate and physiological condi-
tion of individual plants.
mataceae) is widely distributed in China and is com-
This text was submitted by the authors in English.
monly considered as an important economic hygro-
phyte because of the quality of its products and use in
medicine. However, the information about the accumu-
lation and toxicity of Cd in
is scarce. In
was used as the experimental
model to investigate the changes of some physiology
and biochemistry of roots and leaves caused by Cd
pollution. The main objective of the present investiga-
tion was to increase our understanding of the effects of
different concentrations of Cd
on the growth of
plants. The study will be helpful in offer-
ing a theoretical reference for bio-monitoring the level
of Cd in polluted water bodies.
MATERIALS AND METHODS
Growth conditions and metal treatments.
L. were collected from the
Shuang Zhazhen Plantation Farm, Nanjing, China.
Morphologically similar bulbs were precultured in 5%
Hoagland solution. When the ﬁrst true leaf entirely out-
Growth Responses of
L. Plants to Water
Contamination with Cadmium
J. Z. Hu
, D. L. Pei
, F. Liang
, and G. X. Shi
Key Laboratory of Plant and Microorganism Interaction, Department of Life Science,
Shangqiu Normal University, Shangqiu, 476000 China;
fax: +86-370-259-5979; e-mail: firstname.lastname@example.org
Institute of Plant Cell and Molecular Biology, College of Life Science, Nanjing Normal University,
Nanjing 210097, China
Received February 4, 2008
—Cadmium accumulation, the relative content of different chemical forms of Cd, as well as the toxic effect
of Cd on nutrient element uptake, physiological parameters, and ultrastructure of
were determined after the seedlings were exposed to different Cd concentrations for 4 days. The results showed
had the ability to accumulate large amounts of Cd. In the root, stem, and bulb, the predomi-
nant chemical Cd forms were NaCl extractable. With an increase in the Cd
concentration, the chlorophyll con-
tent, the relative membrane penetrability (RMP) of root cells, peroxidase (POD) activity, superoxide dismutase
(SOD) activity in leaves, malondiadehyde (MDA) content and the superoxide anion ( ) generation rate in
roots all decreased following an initial increase. On the other hand, catalase (CAT) activity, SOD activity in
roots, MDA content, and the generation rate of in leaves all increased gradually. The toxic effect of Cd
was more severe on roots than on leaves at the same concentration. Cadmium affected the mineral nutrition bal-
ance; mainly, it promoted the uptake of Ca, Cu, Mn, and Fe, while inhibited Mg, Na, and K uptake. The phys-
iological toxic effect of Cd
was close to the ultrastructural damage induced by Cd contamination. A signiﬁ-
cant correspondence was observed between the Cd dose and its toxic effect. Cadmium could destroy the normal
ultrastructure, disturb the ion balance, and interfere with cell metabolism.
Key words: Sagittaria sagittifolia - cadmium - chemical form - ultrastructure - toxic effect
: CAT—catalase; MDA—malondiadehyde; POD—
peroxidase; RMP—relative membrane penetrability; ROS—reac-
tive oxygen species; SOD—superoxide dismutase; TEM—trans-
mission electron microscope.