ISSN 1021-4437, Russian Journal of Plant Physiology, 2006, Vol. 53, No. 2, pp. 205–210. © MAIK “Nauka /Interperiodica” (Russia), 2006.
Original Russian Text © E.V. Mashkina, A.V. Usatov, V.A. Danilenko, N.S. Kolokolova, E.P. Gus’kov, 2006, published in Fiziologiya Rastenii, 2006, Vol. 53, No. 2, pp. 227–234.
Under varying environmental conditions, the plant
responses to adverse environmental factors by a cas-
cade of reactions maintaining the life of the organism.
Primary response to a stressor is directed to a rapid get-
ting rid of adverse stress consequences, whereas long-
term adaptation is directed to the maintenance of organ-
ism functioning as a whole system under retained stress
conditions [1, 2].
The level of living organism tolerance depends on its
adaptive potential, which, in its turn, depends on its gen-
otype. In plant cells, three genetic subsystems function:
nuclear, chloroplast, and mitochondrial genomes.
Although plastidal and mitochondrial genomes have a
small informational capacity as compared to the nuclear
genome, functionally they are involved in the most
important physiological processes in autotrophs, photo-
synthesis and respiration; and these functions, more than
others, determine plant adaptive responses to stress.
There some reports about
tome mutations resistant to antibiotics [3–6]. The mito-
chondrial mutant of
ized by a low content of reactive oxygen species in leaf
tissues, changes in expression of some antioxidant
enzymes, and increased resistance to stresses [7, 8].
However, in spite of an evident signiﬁcance of extracel-
lular genetic determinants in the plant life and resis-
tance development, their role in these processes
remains poorly studied. The collection of chlorophyll
mutants, we have at our disposal, is a convenient mate-
rial for such experiments . In this connection, the
objective of our study was to investigate the role of sun-
ﬂower extranuclear genomes in plant tolerance to tem-
perature and oxidative stresses.
MATERIALS AND METHODS
In order to assess the role of nuclear and cytoplas-
mic genes in plant tolerance to environmental stresses,
we selected the following lines from the collection of
L.) chlorophyll mutants
of Institute of Biology (Rostov State University): initial
inbred line 3629 and derived mutant lines (nuclear
and plastome mutants
rina-3, en:chlorina-5, en:chlorina-6
Based on the
plastome mutant, a partial
with partially changed
structure of both chloroplast and mitochondrial DNA
 and a complete revertant
obtained. In a complete revertant, chlorophyll content
and morphological feature were restored to the level of
control plants (initial line 3629). In the partial revertant,
green-yellow leaf coloration was similar to that in
mutant, but some habitus characteristics
were restored . As a control, we used cv. Donskoi-99
growing in the Rostov oblast, which was kindly pro-
vided by the author of this cultivar Prof. F.I. Gor-
bachenko (Zhdanov Experimental Station of Oil Crops,
Research Institute of Oil Crops).
The seeds of selected lines were treated with
increased temperature (
) during the ﬁrst 6 h after
soaking; oxidative stress was created by hyperbaric
Responses of Sunflower Chlorophyll Mutants
to Increased Temperature and Oxidative Burst
E. V. Mashkina, A. V. Usatov, V. A. Danilenko,
N. S. Kolokolova, and E. P. Gus’kov
Institute of Biology, Rostov State University, pr. Stachki 194/1, Rostov-on-Don, 344090 Russia;
e-mail: email@example.com; firstname.lastname@example.org
Received May 11, 2005
—A tolerance of nuclear, plastome, and mitochondrial mutants of sunﬂower (
to extreme factors, increased temperature and oxidative stress, which was simulated by hyperbaric oxygenation
was studied. In model experiments, activities of superoxide dismutase and catalase were assayed; cytogenetic
analysis was used for the assessments of proliferative activity of cells in the root meristem; in ﬁeld experiments,
seedling emergence and growth at the stage of 3–4 leaf pair were evaluated. Most tolerant to increased temper-
ature and oxygen pressure were a plastome
mutant and a partial revertant
a changed structure of mitochondrial DNA.
Key words: Helianthus annuus - extranuclear mutants - oxidative stress - temperature stress - tolerance
: FA—fatty acid; HBO—hyperbaric oxygenation;
MI—mitotic index; POL—peroxidation of lipids; SOD—super-
oxide dismutase; TS—temperature stress.