ISSN 1021-4437, Russian Journal of Plant Physiology, 2017, Vol. 64, No. 3, pp. 361–367. © Pleiades Publishing, Ltd., 2017.
Responses of Antioxidant Gene and Enzymes to Salinity Stress
in the Cuminum cyminum L.
Z. Soleimani, A. S. Afshar*, and F. S. Nematpour
Department of Biology, Neyshabur Branch, Islamic Azad University, Neyshabur, Iran
Received November 8, 2015
Abstract– Salt stress as a major limiting factor negatively affects many physiological processes in plants.
Salinity promotes the generation of reactive oxygen species and subsequently oxidative damage of cellular
components. Plant salt stress tolerance requires activation of antioxidative pathways to prevent plant cell from
injurious effects. In this study real-time quantitative reverse transcription–polymerase chain reaction was
used to determine the protective role of two antioxidant genes, i.e. iron-superoxide dismutase (Fe-SOD) and
catalase (CAT) in Cuminum cyminum L. after their treatment with 50, 100, 150 and 200 mM NaCl. Enzymatic
activities were assayed spectrophotometrically for three antioxidants. Moreover, growth parameters, protein
content and proline accumulation were measured. In comparison with the control plants, those plants which
were exposed to 50 and 100 mM NaCl concentration accumulated higher levels of proline. At 50, 100 and
150 mM of NaCl plants showed higher superoxide dismutase, ascorbate peroxidase and catalase activities.
The same condition also induced expression of the Fe-SOD and CAT genes at mRNA level. Protein content
of the treated plants was significantly decreased at 50 mM NaCl and remained constant at other concentra-
tions. Whereas, the growth parameters, with one exception in case of shoot length, did not change at plants
receiving low and mild salt concentrations of up to 150 mM NaCl, 200 mM of NaCl affected these parameters
negatively. From these details, it can be concluded that C. cyminum respond to salt stress by antioxidant sys-
tem efficiency and proline accumulation.
Keywords: Cuminum cyminum, antioxidant enzymes, gene expression
Salinity stress affects metabolism of plant cells,
causes growth and development inhibition, reduction
in photosynthesis, respiration and protein synthesis in
sensitive species and leads to loss of productivity .
Salinity in the soil and irrigation water is an environ-
mental problem and a major constraint for crop pro-
duction. Currently, c. 20% of the world’s cultivated
lands is affected by salinity, which results in the loss
of c. 50% of agricultural yield .
Several studies have shown that ROS and oxidative
stress are responsible for at least some of the toxic
effects of NaCl in plants [3, 4]. Production of reactive
oxygen species (ROS) such as hydrogen peroxide
), superoxide ( ) and the more toxic hydroxyl
radicals ( ), are the common features of all aerobic
organisms during their normal metabolic activities.
Under normal conditions generation and degradation
of ROS is well regulated in plant cell. But their abun-
dance increases when plants are subjected to various
biotic and abiotic stresses . So, in plants under nor-
mal growth conditions, antioxidant defenses are able
to scavenge ROS, whereas, in plants under salinity or
other stressful conditions, like drought, UV radiation,
ozone, chilling, heat shock and pathogen attack, the
antioxidant capacity may be reduced to cope with the
ROS production. The control of the steady-state con-
centrations of ROS by enzymatic and non-enzymatic
antioxidants is critical to protect plant cells of oxida-
tive damage .
ROS scavengers that eliminate the cytotoxic effects
of ROS, under various stress conditions, include
enzymes such as superoxide dismutase (SOD), cata-
lase (CAT), glutathione peroxidase (GPX) and the
four enzymes of the ascorbate-glutathione cycle of
ascorbate peroxidase (APX), monodehydroascorbate
reductase (MR), dehydroascorbate reductase (DR)
and glutathione reductase (GR). They also include
some non-enzymatic compounds such as glutathione,
The article is published in the original.
Abbreviations: APX—ascorbate peroxidase; CAT—catalase;
DR—dehydroascorbatereductase; GPX—glutathione peroxi-
dase; GR—glutathione reductase; H
MR—monodehydroascorbate reductase; NBT—nitro blue
tetrazolium; —superoxide radical; —hydroxyl radical;
—singlet oxygen; SOD—superoxide dismutase..