1021-4437/03/5004- $25.00 © 2003
Russian Journal of Plant Physiology, Vol. 50, No. 4, 2003, pp. 455–459. Translated from Fiziologiya Rastenii, Vol. 50, No. 4, 2003, pp. 511–516.
Original Russian Text Copyright © 2003 by Komarova, Vyskrebentseva, Trunova.
Plant hardening to freezing involves the metabolic
rearrangements affecting all aspects of cell life. Numer-
ous publications indicate that low temperatures change
the plastic and energy metabolism [1, 2].
Recently lectins were reported to participate in plant
responses to adverse environmental conditions. Lectin
activities were shown to increase under osmotic ,
wounding , and salinity  stresses. Lectin activity
of the cell walls was also considerably enhanced under
low temperature conditions, and therefore these lectins
are believed to participate in cell responses to various
external agents [6, 7].
Lectins were found in the plasmalemma and in the
membranes of such organelles as nuclei, plastids, and
mitochondria [8–10]; apparently lectins are essential
for membrane receptor and transport functions and in
this way participate in cell responses to various external
agents, including low temperatures.
This study became necessary because of the lack of
data concerning the changes in the surface properties of
organelle membranes when affected by low abovezero
temperatures. Our goal was to follow HA changes in
the lectin-like proteins from the cell walls and outer
organelle membranes and the interactions of these pro-
teins with endogenous ligands in winter wheat seed-
lings in the course of hardening. Such changes can
affect the functional activities of cell membranes and,
therefore, must play an important role in the processes
of cold adaptation; hence, the study of these changes
would help better understand plant adaptation pro-
cesses under low temperature conditions.
MATERIALS AND METHODS
Three-day-old seedlings of freezing-tolerant winter
L., cv. Mironovskaya 808)
were used in this study. Seeds were germinated for
three days in petri dishes, 50 seeds per dish, on ﬁlter
paper moistened with water in darkness at 20
ing tolerance was assessed in hardened and nonhard-
ened seedling using the following method : seed-
lings were placed into a freezing chamber for 24 h at
C, then for 24 h at –7
C and then transferred into a
defrosting chamber at 2
Activity of Lectin-Like Proteins of the Cell Walls and the Outer
Organelle Membranes as Related to Endogenous Ligands
in Cold-Adapted Seedlings of Winter Wheat
E. N. Komarova, E. I. Vyskrebentseva, and T. I. Trunova
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276 Russia;
fax: 7 (095) 977-8018; e-mail: email@example.com
Received March 6, 2002
—The hemagglutinating activity (HA) of lectin-like components in the cell walls and the outer
organelle membranes was studied in freezing-tolerant winter wheat (
L., cv. Mironovskaya
808) plants in the course of hardening at 2
C, in parallel with the effects of endogenous ligands from the soluble
fraction on HA. Low hardening temperature divergently changed HA of the lectin-like components in the cell
walls, the outer membranes of nuclei, plastids, and mitochondria, and the microsomal membranes: HA
increased in the cell walls, nuclei, and plastids and decreased in the mitochondria and microsomal membranes.
Under hardening conditions, with plant growth slowed down, HA of the lectin-like proteins from the outer
organelle membranes was inhibited in the presence of the soluble fraction components (soluble ligands); such
inhibition was not observed in the case of actively growing nonhardened seedlings. The authors put forward a
hypothesis that the lectin-like proteins from both peripheral (cell walls) and intracellular (outer organelle mem-
branes) compartments are essential for developing freezing tolerance. HA of the cell walls and the outer mem-
branes of nuclei and plastids enhanced by hardening manifested positive correlation with freezing tolerance and
negative correlation with the growth rate. In contrast, HA of the outer membranes of mitochondria and
microsomes was positively related to plant growth and negatively, to freezing tolerance. As negative and posi-
tive effectors of membrane-dependent processes, the lectin-like components of the outer organelle membranes
seem to control membrane functional activities in the course of cold adaptation.
Key words: Triticum aestivum - seedlings - outer organelle membranes - cell walls - lectin-like proteins - endog-
enous ligand - cold adaptation
: HA—hemagglutinating activity.