ISSN 1021-4437, Russian Journal of Plant Physiology, 2006, Vol. 53, No. 6, pp. 746–750. © MAIK “Nauka /Interperiodica” (Russia), 2006.
Original Russian Text © L.D. Garaeva, S.A. Pozdeeva, O.A. Timofeeva, L.P. Khokhlova, 2006, published in Fiziologiya Rastenii, 2006, Vol. 53, No. 6, pp. 845–850.
The investigation of the mechanisms of plant adap-
tation to variable environment is tightly related to the
solving the problems of plant resistance and introduc-
tion. Plant adequate responses to various stressors
depend on cell signaling systems providing for coordi-
nated functioning of defense and adaptation systems.
Cell-wall lectins could by an important component of
such systems. Due to their high speciﬁcity toward car-
bohydrate determinates of complex glycoconjugates,
lectins could be involved in the interaction between the
cell wall and plasma membrane.
The extracellular matrix in combination with the
plasma membrane and cytoskeleton represents a struc-
turally and functionally coupled system responsible for
recognizing and transduction of environmental stress
signals [1, 2]. The plant cell wall, being a metabolically
active and dynamic compartment [3, 4], is involved in
the development of winter plant frost resistance . In
the cell wall subjected to the action of low temperature,
the content of extensions increases, some enzyme activ-
ities enhance, and protein composition changes [6, 7].
Although lectins are present in the cell wall  and
their behavior depends on the structural integrity of the
cytoskeleton , essentially nothing is known about the
regulatory mechanisms of their activity and changes in
their composition under unfavorable environmental
conditions, low temperature in particular. In this con-
nection, the objective of this work was to study changes
in the polypeptide composition and functional activity
of cell-wall lectins under conditions of winter wheat
acclimation to low temperature.
MATERIALS AND METHODS
Experiments were performed with roots of winter
L., cv. Mironovskaya 808)
seedlings. Plants were grown in trays on tap water at an
irradiance of 100 W/m
and a 12-h photoperiod. Hard-
ening was performed in a special chamber at
7 days. During this period, we took samples for deter-
mination of cell-wall lectin activity and fractional com-
Cell-wall lectins were isolated as described in .
After extraction of soluble lectins, the residue was
homogenized in the medium containing 20 mM K-
phosphate buffer, pH 7.4, 10 mM EDTA, 0.05 mM
dithiotreithol, and 0.5 mM phenylmethylsulfonyl ﬂuo-
ride (PMSF). The homogenate was ﬁltered through two
layers of the cotton cloth. The residue on the cloth, con-
taining cell walls, was washed many times with the
homogenization medium and acetone and then
extracted with the initial medium supplemented with
0.05% Triton X-100 and 0.9% NaCl for 3 h at constant
. After subsequent centrifugation at
for 10 min, the pellet was discarded, whereas
the supernatant (enriched in cell-wall lectins) used for
lectin activity assay and further puriﬁcation.
Cell-Wall Lectins during Winter Wheat Cold Hardening
L. D. Garaeva, S. A. Pozdeeva, O. A. Timofeeva, and L. P. Khokhlova
Faculty of Biology and Soil Sciences, Kazan State University, Kremlevskaya ul. 18, Kazan, Tatarstan, 420008 Russia;
fax: 7 (843) 238-7121; e-mail: Olga.Timofeeva@ksu.ru
Received February 15, 2006
—The polypeptide composition and functional activity of cell-wall lectins from roots of winter wheat
L., cv. Mironovskaya 808) seedlings during cold hardening were studied. Several phases of
lectin activity changes were observed, which indicates their involvement in the development of general adapta-
tion syndrome of the cell. After 0.5-h low-temperature treatment, marked alterations occurred in the proﬁle of
protein elution: lectins with mol wts of 78 and 42.5 kD disappeared and new ones with mol wts of 72, 69, 37,
and 34.5 kD appeared. It was established that 17.5- and 69-kD lectins and most lectins eluted with glucose were
arabinogalactan proteins (AGP), which permitted a supposition that these lectins were involved in the interac-
tion between the cell wall and cytoskeleton. After 7-day-long hardening, total protein content reduced and lec-
tins with mol wts of 69 and 37 kD disappeared, which corresponded to reduced lectin activity by the end of
hardening. A transient appearance of 37- and 69-kD lectins, which are AGP, might indicate their involvement
in the triggering the development of plant-cell defense responses.
Key words: Triticum aestivum - cell wall - lectins - arabinogalactan proteins - low-temperature hardening
: AGP—arabinogalactan proteins; PMSF—phenyl-
methylsulfonyl ﬂuoride; WGA—wheat germ agglutinin.