1021-4437/03/5005- $25.00 © 2003
Russian Journal of Plant Physiology, Vol. 50, No. 5, 2003, pp. 661–665. Translated from Fiziologiya Rastenii, Vol. 50, No. 5, 2003, pp. 738–743.
Original Russian Text Copyright © 2003 by Rozhnova, Gerashchenkov, Babosha.
Early stages of viral pathogenesis are accompanied
by the oxidative burst including enhanced lipid peroxi-
dation and the changed activity of the antioxidant sys-
tems . In this connection, the ideas of the therapeutic
potential of the lipid inhibitors of free-radical reactions
acquire a great signiﬁcance. These inhibitors suppress
lipid peroxidation and thus improve resistance to viral
diseases. The application of natural antioxidants, such
as arichidonic acid (AA), in SAR induction is of con-
siderable theoretical and practical interest.
Plant systemic resistance to fungal and bacterial dis-
eases induced by AA and its derivatives has long been
the subject of investigation [2–4]. However, the antivi-
ral effects of AA in plants are still not satisfactorily
studied [5–8] and, therefore, induce an interest to AA as
a potential activator of antiviral resistance. Lectins
(phytohemagglutinins) play a role in plant defense
against various pathogens [8–10]. Therefore, we
decided to study the changes in lectin activity during
the development of systemic antiviral resistance
induced by AA.
MATERIALS AND METHODS
Tobacco plants (
L., cv. Samsun
NN) were used at the age of six to eight weeks (cv.
Samsun displays a hypersensitivity to TMV infection).
Plants were grown under aseptic conditions in soil
under an illuminance of 9 klx, a photoperiod of 16 h,
and a day/night temperature of 22–23/20
The content of TMV in plant material was estimated
by the ELISA technique, using a diagnostic monova-
lent kit produced at the Research Institute of Potato
Growing, according to the manufacturers’ protocol.
AA (Fluka, Switzerland) was applied at the concen-
tration of 10
M, which was optimal for the improve-
ment of antiviral resistance. Control leaves were treated
with distilled water. Before application, the AA solu-
tion and viral inocula were sterilized by passing
through FlowPore D ﬁlters with a pore diameter of
m (Sartorius, Germany).
Tobacco leaves were infected with common TMV
strain. Its concentration was estimated from the solu-
tion optical density at 260 nm, as measured with an
SF-26 spectrophotometer (LOMO, Russia), using the
coefﬁcient of 1.7 for 0.1% solution.
The determination of the AA concentration most
effectively suppressing virus reproduction (preinfec-
tion and postinfection treatments) and the experiments
on its immunostimulating activity were performed as
described in .
The Effect of Arachidonic Acid and Viral Infection
on the Phytohemagglutinin Activity during the Development
of Tobacco Acquired Resistance
N. A. Rozhnova*, G. A. Gerashchenkov*, and A. V. Babosha**
* Institute of Biochemistry and Genetics, Russian Academy of Sciences, Ufa Research Center,
pr. Octyabrya 69, Ufa, 450054 Russia;
fax: 8 (3472) 35-6100; e-mail: email@example.com
** Main Botanical Garden, Russian Academy of Sciences, Botanicheskaya ul. 4, Moscow, 127276 Russia
Received February 6, 2001
—The effects of arachidonic acid (AA) on the development of viral infection and the activity of phy-
L. plants were studied. Cv. Samsun NN was used, which displayed a
genotypically determined hypersensitive response to tobacco mosaic virus (TMV) infection. When tobacco leaf
disks were treated with 10
M AA, viral reproduction was suppressed by 90–100%. The AA concen-
tration of 10
M was optimal for the improvement of plant virus resistance. Tobacco leaves maintained virus
resistance for at least two weeks. Both AA treatment and TMV inoculation were accompanied by an enhanced
lectin activity, which may indicate the involvement of lectins in the development of plant defense responses.
Lectin accumulation was observed in the intact plants developing systemic resistance and in the detached leaves
characterized by local resistance.
Key words: Nicotiana tabacum - arachidonic acid -phytohemagglutinins (lectins) - antiviral activity - systemic
: AA—arachidonic acid; SAR—systemic acquired
resistance; TMV—tobacco mosaic virus.