ISSN 1021-4437, Russian Journal of Plant Physiology, 2007, Vol. 54, No. 3, pp. 360–365. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © V.N. Popov, D.N. Fedorin, A.T. Eprintsev, 2007, published in Fiziologiya Rastenii, 2007, Vol. 54, No. 3, pp. 409–415.
Succinate:ubiquinone oxidoreductase (succinate
dehydrogenase, SDH, EC 184.108.40.206) is a part of complex
II of the electron transport chain (ETC) in mitochon-
dria. It converts succinate to fumarate and ubiquinone
to ubiquinol. SDH is involved in both the TCA cycle
and the ETC. In eukaryotic organisms, the SDH com-
plex is composed of four polypeptides. The polypeptide
SDH1 is covalently bound to FAD, while SDH2 carries
three Fe–S clusters. SDH1 and SDH2 are at the matrix
side of the membrane and are attached to the mitochon-
drial membrane via cytochrome
-enriched SDH3 and
SDH4 [1, 2]. Such membrane-bound complex is able to
reduce ubiquinone, but the SDH1–SDH2 dimer can
only oxidize succinate . The natural acceptor for the
dimer is not found.
Complex II in the mitochondria of
is encoded by the nuclear genome. There are
two genes for SDH1:
; three genes
; two genes
; and one gene for
The fact that SDH is encoded by a large number of
genes suggests that this enzyme plays an important role
in the regulation of plant metabolism. It seems impor-
tant to study the expression level of each of these genes
under different conditions.
Many reports on the expression of genes of the Fe-
S-containing subunit SCD2 are available. Thus, for
example, Alvaro et al.  showed that the SDH2 gene
expression changed during germination of Arabidopsis.
In dormant seeds, only the
expressed, but by the 15th hour after germination, the
genome functioning was rearranged and the expression
of this gene ceased while the expression of
genes significantly increased. In another work
 was shown that the expression of genes encoding
the SDH2 changed in different parts of the ﬂower dur-
ing Arabidopsis ﬂowering.
However, very few studies addressed the regulation
of expression of the FAD-containing subunit of SDH,
genes in particular, in response to
different environmental factors.
It seems important to study the relationship of such
important processes as photosynthesis, photorespira-
tion, and respiration in the plant cell. Among other
things, the phytochrome system is involved in the regu-
lation of these processes . The phytochrome system
was previously shown to take part in the regulation of
the activity of the key enzyme involved in plant respira-
tion, SDH : in the light the activity of this enzyme
was suppressed, possibly due to the effect of the active
form of phytochrome.
Phytochrome is known to be involved in the regula-
tion of activity of many enzymes. It was shown that
phytochrome changed the nitrate reductase gene
expression, leading to changes in the amount of the
Light Regulation of Succinate Dehydrogenase Expression
V. N. Popov, D. N. Fedorin, and A. T. Eprintsev
Voronezh State University, Universitetskaya pl. 1, Voronezh, 394006 Russia;
fax: 7(4732) 208755; e-mail: email@example.com
Received July 30, 2006
—A potential mechanism of light regulation of the succinate dehydrogenase (SDH) expression in
leaves was studied. As was shown by dot-hybridization and polymerase chain reaction in
real time (RT-PCR), the SDH mRNA level in wild-type
plants changed depending on light
conditions. The level of SDH mRNA in darkness was higher than in the light. The analysis of
plants carrying the mutant genes of phytochromes A and B showed that phytochrome A was involved
in the regulation of the SDH enzyme activity. The active form of phytochrome A suppressed the
expression, and that resulted in decreasing activity of SDH.
Key words: Arabidopsis thaliana - succinate dehydrogenase - enzyme activity - gene expression - phytochrome
: DCPIP—dichlorphenol indophenol; ETC—elec-
tron transport chain; FRL—far-red light; PCR—polymerase
chain reaction; PMS—phenazine metasulfate; RL—red light; RT-
PCR—PCR in real time; SDH—succinate dehydrogenase; SSC-
buffer—buffer containing 75 mM sodium citrate and 750 mM
NaCl, pH 7.0.