1021-4437/05/5203- © 2005
Russian Journal of Plant Physiology, Vol. 52, No. 3, 2005, pp. 320–325. Translated from Fiziologiya Rastenii, Vol. 52, No. 3, 2005, pp. 366–371.
Original Russian Text Copyright © 2005 by Zagoskina, Olenichenko, Klimov, Astakhova, Zhivukhina, Trunova.
Adaptation to various adverse environmental factors
is one of the important aspects of the plant life, which
is the subject of much investigation [1, 2]. Among these
factors is below-zero temperature; the effect of this fac-
tor is frequently studied on winter cereals, wheat in par-
ticular [3, 4]. Plant capability for adaptation to low tem-
peratures during their overwintering is provided by
diverse physiological and biochemical mechanisms,
many of which are well studied at present. These mech-
anisms primarily include changes in carbohydrate,
lipid, and protein metabolism. Thus, low-temperature
adaptation was shown to be accompanied by the accu-
mulation of a large amount of sugars and phospholipids
and by the synthesis of some stress proteins [3, 5, 6].
Some adaptive changes occur also in the cell ultrastruc-
ture, in the photosynthetic apparatus in particular,
although the photosynthesis rate remains at a rather
high level during cold hardening [4, 7].
One of the speciﬁc properties of higher plants is
their capacity for the synthesis of diverse secondary
metabolites [8, 9], phenolic compounds in particular.
Phenolics are synthesized in essentially all plant cells
. They fulﬁll diverse functions related to photosyn-
thesis, respiration, and plant defense against various
stressors (pathogens, UV-B radiation, heavy metals,
and others) [1, 10–12]. However, until now little is
known about the role of phenol metabolism in plant
adaptation to low-temperature stress [13, 14]. At the
same time, phenolics are undoubtedly involved in this
process, in particular due to their high antioxidant
activity, which is of importance for cell survival under
stress conditions [1, 15].
The objective of this work was to study the changes
exchange and production of various phenolic
compounds during winter wheat cold hardening. The
interrelation between these two processes is obscure,
exchange affects general plant metabo-
lism, which must have an effect on phenolics synthesis
MATERIALS AND METHODS
Experiments were performed with a
widely cultivated and highly frost-resistant cultivar of
winter wheat (
L., cv. Mironovskaya
808). Sowing was performed during the ﬁrst decade of
September (the optimum time for sowing in Moscow
oblast). Plants were grown in soil culture (in boxes
ﬁlled with soddy-podzolic soil) under natural condi-
tions until the phenophase of thillering (45–60 days).
At the end of growing period, plants were subjected to
the action of hardening around-zero temperatures.
Thereafter, some plants were transferred to the cold
greenhouse and left at naturally decreasing tempera-
tures varying from 7 to
for further hardening
(experimental plants). Other plants were transferred to
the phytotron chamber where they grew at
natural illumination (control plants).
The Effects of Cold Acclimation of Winter Wheat Plants
on Changes in CO
and Phenolic Compound Formation
N. V. Zagoskina*, N. A. Olenichenko*, S. V. Klimov*,
N. V. Astakhova*, E. A. Zhivukhina**, 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
**Pedagogical State University, Moscow
Received October 5, 2004
—We studied CO
exchange and phenolic compound production in various organs of unhardened and
hardened winter wheat (
L.) plants. The rates of CO
assimilation at saturating illumination
(photosynthesis) and CO
evolution in darkness (respiration) declined substantially at the autumnal decrease of
ambient temperature. However, because of a higher cold resistance of photosynthesis, the ratio of photosynthe-
sis to respiration rates increased 1.5-fold. These gas exchange changes were accompanied by the accumulation
of total soluble phenolics in leaves and a polymeric phenolic compound lignin in roots. We did not observe any
changes in the production of either soluble or polymeric (lignin) phenolics in crowns.
Key words: Triticum aestivum - winter wheat - CO
exchange - phenolic compounds - lignin - cold hardening