ISSN 10214437, Russian Journal of Plant Physiology, 2010, Vol. 57, No. 1, pp. 144–147. © Pleiades Publishing, Ltd., 2010.
Original Russian Text ©V.N. Popov, O.V. Antipina, T.I. Trunova, 2010, published in Fiziologiya Rastenii, 2010, Vol. 57, No. 1, pp. 153–156.
Temperature is one of the most significant limiting
environmental factors determining plant geographic
spreading and productivity. Since plants have no
mechanisms of temperature regulation, they are
forced continuously to adapt to environmental tem
perature oscillations . The problem of cold toler
ance is especially important for coldsensitive plants of
tropical and subtropical origin, which are especially
sensitive to low temperatures .
Plant tolerance to low temperature is a multifac
eted property developing in the process of lowtem
perature adaptation, i.e., during the formation of plant
cold or frost tolerance [3, 4]. Lowtemperature adap
tation of frosttolerant plants is best studied; after lab
oratory hardening, some of such plants can tolerate
very low temperatures, down to the temperature of liq
uid helium (
). As distinct from frosttolerant
plants, coldsensitive plants can be damaged by low
abovezero temperatures; they could adapt only to a
limited range of low temperatures .
It is known that chilling of coldsensitive plants ini
tiates ROS generation in their cells due to disturbances
in the functioning of electrontransport chains [5, 6].
ROS generated during cold stress activate POL pro
cesses. Firstly, primary molecular POL products
appear, dienoic conjugates and lipid hydroperoxides.
Thereafter, these primary products are subjected to
further conversions with the formation of secondary
POL products, MDA among them [7, 8]. As this takes
place, the amount of unsaturated FAs in membrane
lipids decreases, which is accompanied by reduced cell
membrane fluidity and their increased permeability
. These processes can result in plant metabolism dis
turbance and even plant death . In this connection,
the analysis of POL product accumulation during low
temperature adaptation of coldsensitive plants is of
importance for elucidation of the mechanisms of cold
sensitive plant tolerance to hypothermia.
It should be noted that most researchers paid main
attention to oxidative stress in the leaves. Neverthe
less, plant tolerance to low temperatures is known to
be determined to a large degree by a high root sensitiv
ity to low temperature, and the cases of this sensitivity
are not well studied [11, 12].
The objective of this work was to investigate low
temperature adaptation of coldsensitive tobacco
plants in connection with lipid peroxidation in their
leaves and roots.
MATERIALS AND METHODS
Experiments were performed with 6weekold
coldsensitive tobacco plants (
cv. Samsun). Plants were propagated by cuttings and
cultured on the mineral substrate at
, a 16h pho
toperiod, and an illuminance of 5 klx in the chamber
of phytotron at Timiryazev Institute of Plant Physiol
ogy, RAS. Plants had 6–7 leaves weighing on the aver
age 3 g, stem was 6–8 cm high, and the weight of the
root system was 1.25–1.5 g.
Plants were hardened during 6 days at
Binder KBW240 climatic chamber (Germany). This
Lipid Peroxidation during LowTemperature Adaptation
of ColdSensitive Tobacco Leaves and Roots
V. N. Popov, O. V. Antipina, and T. I. Trunova
Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya ul. 35, Moscow, 127276 Russia;
fax: 7 (495) 9778018, email: email@example.com
Received March 11, 2009
—We studied lowtemperature adaptation of coldsensitive tobacco plants in relation to peroxidation of
lipids (POL) in their leaves and roots. Experiments were performed with tobacco plants (
Samsun). Cold hardening (6 days at 8
C) exerted principally different action on tobacco leaves and roots. In the
leaves, the contents of dienoic conjugates and MDA was reduced, and tissue cold tolerance, even to below zero
temperatures, was improved. In contrast, in the roots, POL was activated and root cold tolerance decreased. It is
suggested that an incapability of the tobacco root system to adapt to low temperature was a limiting factor deter
mining the low potential of this and other coldsensitive plants to hypothermia.
Key words: Nicotiana tabacum leaves and roots hypothermia lowtemperature adaptation lipid peroxidation
DC—dienoic conjugates; POL—peroxidation of