ISSN 10214437, Russian Journal of Plant Physiology, 2011, Vol. 58, No. 6, pp. 1055–1061. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © M.Yu. Dmitryukova, A.Kh. Baimiev, V.V. Fedyaev, Z.F. Rakhmankulova, 2011, published in Fiziologiya Rastenii, 2011, Vol. 58, No. 6, pp. 915–921.
Leghemoglobin (legoglobin, Lg) is a myoglobin
like hemoprotein transferring oxygen and having a
very high affinity for oxygen . Lg is synthesized in
the nodules of symbiotic legumes. Its function is the
maintenance of the low oxygen concentration suffi
cient for respiration of bacteroids but insufficient for
inactivation of nitrogenase sensitive to oxygen . Lg
was shown to enhance oxygen uptake by plant mito
chondria  and is capable of interaction with reactive
species of oxygen (ROS) and nitrogen, thus manifesting
anti or proxidant properties , i.e., participating in
plant protection against oxidative nitrosative stress .
In addition to symbiotic hemoglobins (Hgs), plants
comprise nonsymbiotic and truncated Hgs, such as
bacterial ones. Nonsymbiotic Hgs are fairly wide
spread in the plant kingdom and are stressinduced
The literature contains conflicting evidence con
cerning the impact of Hb genes of different origin on
the growth and development of transgenic plants.
Thus, it was shown that transgenic tobacco expressing
Hg gene exhibited enhanced growth .
Other researchers found no significant changes in
growth and development of such plants . At the
same time, expression of soybean Lg A gene in potato
and tomato plastids caused inhibition of growth [9, 10].
Since the main function of most nonsymbiotic Hg
is to protect plants against a variety of adverse factors,
it is important to study the effect of Hg on the metab
olism of symbiotic plants under stressful conditions.
The source of nonspecific oxidative stress may serve
heavy metals, including cadmium, which does not
participate in the normal plant metabolism and is toxic
even at low concentrations .
The objective of this work was production of trans
genic tobacco plants expressing the soybean Lg A gene
and studying parameters characterizing growth,
energy metabolism, intensity of lipid peroxidation
(POL), and activities of antioxidant enzymes in
tobacco plants under normal conditions and under
oxidative stress induced by toxic concentrations of
MATERIALS AND METHODS
Bacterial strains and plasmids.
We used bacteria
strain XL1Blu and
strain AGL0. For plant transformation a
binary vector pCambia 1301, kindly presented by the
Effect of Leghemoglobin A Gene Expression from Soybean
on Tobacco Plant Growth and Antioxidant State
under Damaging Action of Cadmium
M. Yu. Dmitryukova
, A. Kh. Baimiev
, V. V. Fedyaev
, and Z. F. Rakhmankulova
Department of Plant Physiology, Faculty of Biology, Bashkir State University, ul. Zaki Validi 32, Ufa, 450007 Russia;
Institute of Biochemistry and Genetics, Russian Academy of Sciences, Ufa Research Center, Ufa, Russia
Received February 25, 2011
—Transgenic tobacco (
L. plants, cv. Samsun) bearing the gene for soybean (
(L.) Merr.) leghemoglobin A under the control of 35S CaMV promoter were produced. The effects
of this gene expression on tobacco growth and respiration, MDA content, and also activities of catalase and
guaicol peroxidase were studied. The growth rate of transformed plant was reduced, respiratory losses were
increased, and lipid peroxidation was substantially suppressed. In plants expressing the laghemoglobin A
gene, the negative effects of toxic cadmium concentrations on growth parameters and plant oxidative status
Keywords: Nicotiana tabacum
, soybean leghemoglobin A, cadmium, growth, respiration, alternative respira
tion, lipid peroxidation.
: AO—alternative oxidase; Hg—hemoglobin; Lg—
leghemoglobin; MS—Murashige and Skoog nutrient medium;
—gross photosynthesis; POL—peroxidation of lipids;
adaptation respiration; RGR—relative growth rate;
respiration; W—plant dry weight.