ISSN 10214437, Russian Journal of Plant Physiology, 2013, Vol. 60, No. 6, pp. 776–784. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © N.I. Gazizova, N.V. Petrova, F.G. Karimova, 2013, published in Fiziologiya Rastenii, 2013, Vol. 60, No. 6, pp. 819–827.
Anthropogenic pollution of environment by the
salts of heavy metals (HM) belonging to the group of
supertoxicants is now one of the actual problems.
Despite numerous studies on HM, there is a shortage
of knowledge about the physiological, biochemical,
and molecular mechanisms of some HM action on liv
ing organisms, including plants.
Tungsten is an element that has biological signifi
cance only for the limited number of living organisms
. It may be present in phosphate fertilizers, house
hold waste, the waste of heavy, light, and the military
industries [2, 3]. The widespread application of tung
sten derivatives contributes to its accumulation in the
environment [3, 4]. It was previously thought that this
TM is relatively safe. Recent studies have shown that it
can be toxic to animals and plants [3, 5, 6].
Tungsten availability to the living organisms
depends on pH of the ambient medium. At low pH
values, tungsten is converted into trioxide (
which is insoluble and unavailable to the cells. How
ever, pH of some natural water bodies and farmed soils
facilitates tungsten solubilization in the form of tung
state. As oxoanion, this HM is easily available for
plants, which is confirmed by its dosedependent con
tent in them . Tungstate penetration into the cell
occurs with the help of ABCtype transporters. There
after, it is bound to the Cnx1 protein localized in the
peripheral layer of the cytoplasm .
Usually, the negative effect of HM is studied in
relation to their impact on the antioxidant status of
plant cells and the development of oxidative stress.
However, there are almost no studies analyzing the
effect of HM on the activities of enzymes catalyzing
protein phosphorylation/dephosphorylation (protein
kinases and protein phosphatases), one of the most
important posttranslational protein modifications
(PTM). This PTM is a highly conserved mechanism
for regulating the activities of proteins, their subcellu
lar localization, and dynamic behavior of supramolec
Effect of Tungstate on Pea Root Growth and Protein
N. I. Gazizova, N. V. Petrova, and F. G. Karimova
Kazan Institute of Biochemistry and Biophysics, Kazan Research Center, Russian Academy of Sciences,
ul. Lobachevskogo 2/31, Kazan, Tatarstan, 420111 Russia;
Fax: +7 (843) 2977347; email: email@example.com
Received September 27, 2012
—Tungsten belong to heavy metal group, which physiological, biochemical, and molecular action
mechanisms are essentially unstudied despite metal wide application in light, heavy, and military industries
and the gradual accumulation in the environment. Protein phosphorylation/dephosphorylation (one of the
most important posttranslational modifications) is a highly conserved mechanism of intracellular signaling
and regulation of many processes of cell activity. Protein tyrosine phosphorylation/dephosphorylation is
required for the cell cycle processing, plant growth and differentiation. In this work, the effects of sodium
tungstate on pea (
L. cv. Truzhenik) root growth, protein tyrosine phosphorylation, and phos
phatase activity in the roots were studied. It was shown that sodium tungstate suppressed growth, changed the
mitotic index in the root meristem, and delayed cells at some mitosis phases. Under the influence of tung
state, hydrogen peroxide accumulated in the roots and phosphatase activity was inhibited. It was established
by twodimension electrophoresis and immunoblotting with the highly specific to phosphotyrosine antibody
(PY20) that tungstate treatment increased both the number of such proteins and their specific phosphoryla
tion. It is supposed that the inhibition of protein tyrosine phosphatases was one of the reasons for tungstate
induced pea root growth inhibition.
Keywords: Pisum sativum
, tungstate, root growth, proliferation, hydrogen peroxide, phosphatase activity, pro
tein tyrosine phosphorylation
: 2DE—twodimensional electrophoresis; HM—
heavy metals; MI—mitotic index; PK—protein kinase;
PMSF—phenylmethylsulfonyl fluoride; pNPP—pnitrophenyl
phosphate; PP—protein phosphatase; PTM—posttranslational
modification; PTK—protein tyrosine kinase; PTP—protein
tyrosine phosphatase; STP—specific tyrosine phosphorylation.