ISSN 10214437, Russian Journal of Plant Physiology, 2011, Vol. 58, No. 6, pp. 1027–1033. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © Yu.V. Karpets, Yu.E. Kolupaev, T.O. Yastreb, 2011, published in Fiziologiya Rastenii, 2011, Vol. 58, No. 6, pp. 883–890.
Nitric oxide (NO) is a potent effector of numerous
physiological processes in plant and animal cells . It
is known to participate in the development of plant
acclimation responses to various stress agents [1, 2],
especially biotic stressors . The role of nitric oxide
in the formation of symbiosis between legumes and
nodule bacteria has been studied recently .
Participation of nitric oxide in plant adaptive
responses to abiotic stress agents is less investigated.
Some works report about positive effect of exogenous
NO donors on plant resistance to drought, heavy met
als, UVB irradiation [2, 5], and salinity . At the
same time, the data concerning the effect of exoge
nous NO on plant resistance to hyperthermia are still
scanty and ambiguous. For instance, it was shown that
exogenous NO donors elevated heat resistance of rice
seedlings . However, the seeds of Arabidopsis
, lacking functionally active gene
encoding nonsymbiotic hemoglobin that binds NO,
showed the lower germinating capacity at higher tem
peratures as compared with the seeds of wildtype Ara
Biological activity of NO may be realized through
its interaction with other mediators, in particular, with
ROS and calcium ions [1, 5].
It was shown that, in tissue culture of ginseng roots,
NO donor activated NADPHoxidase and boosted
generation of superoxide anion radical .
Introduction of NO donors in the apoplast of wheat
leaves brought about a reduction in the activity of
superoxide dismutase (SOD), the activation of extra
cellular peroxidase, and the accumulation of ROS
. In beans, the effect of exogenous nitric oxide, as
an agent inducing stomatal closure, was not sup
pressed by catalase and was realized irrespective of
ROS . Treatment of detached maize leaves with
NO donor did not lead to the accumulation of hydro
gen peroxide therein, although exogenous hydrogen
peroxide boosted NO generation .
It is known that NO donors bring about an increase
in the content of cytosolic calcium in plant cells .
At the same time, realization of some physiological
NO effects (especially, activation of protein kinases)
irrespective of calcium is discussed . On the whole,
the role of interaction between NO, ROS, and calcium
Effect of Sodium Nitroprusside on Heat Resistance of Wheat
Coleoptiles: Dependence on the Formation and Scavenging
of Reactive Oxygen Species
Yu. V. Karpets, Yu. E. Kolupaev, and T. O. Yastreb
Dokuchaev National Agrarian University, Kommunist1, Khar’kov, 62483 Ukraine;
Received January 31, 2011
—The effect of nitric oxide donor sodium nitroprusside (SNP) on resistance of coleoptiles of 4day
old etiolated seedlings of wheat (
L., cv. Elegiya) to damaging heating (10 min at 43
possible dependence of this effect on changes in the activities of enzymes producing and scavenging reactive
oxygen species (ROS) were studied. Treatment of coleoptiles with 500
M SNP considerably boosted gener
ation of superoxide anion radical therein. This effect was substantially suppressed by blocker of calcium chan
nels (lanthanum chloride), calmodulin antagonist (chlorpromazine), and inhibitor of NADPHoxidase
(imidazole) but not by peroxidase inhibitor (salicylhydroxamic acid). NO donor activated antioxidant
enzymes (superoxide dismutase, catalase, and soluble peroxidase) and elevated heat resistance of wheat
coleoptiles. NO scavenger methylene blue, antioxidant agent ionol, calcium antagonists, and NADPHoxi
dase inhibitor imidazole substantially reduced the elevation of heat resistance of wheat coleoptiles induced
by NO donor. It was concluded that SNPinduced heat resistance of coleoptiles depended on calcium and
ROS, whose production is probably boosted by activation of NADPHoxidase.
Keywords: Triticum aestivum
, nitric oxide, reactive oxygen species, superoxide anion radical, NADPHoxi
dase, calcium, antioxidant enzymes, heat resistance.
: NBT—nitro blue tetrazolium, SHAM—salicylhy
droxamic acid, SNP—sodium nitroprusside, SOD—superoxide