ISSN 10214437, Russian Journal of Plant Physiology, 2013, Vol. 60, No. 3, pp. 359–366. © Pleiades Publishing, Ltd., 2013.
There are many extremely harsh environments,
such as hot springs, salt lakes, and submarine volcanic
habitats with abundant resources of “extremophiles”.
The abnormal temperature, low nutrient levels, abun
dant sunlight, and remote geographical location of
these regions make them relatively special ecosystems
[1, 2]. However, isolation and applications of stress
genes in extremophiles still remains quite limited.
With the excess consumption of resources and the
deterioration of the environment, characterization of
gene information and protein properties of extremo
philes, as well as expression in other organisms prom
ise to be beneficial for tolerance.
Salinity is a global problem that threatens crop
yield and quality [3, 4]. Exposure to severe salt stress
can lead to oxidative damages, ion toxicity, and nutri
tious imbalance . ROS play an important role in
This text was submitted by the authors in English.
these toxic effects . In the antioxidative process,
superoxide dismutase (SOD), as the first defense line,
converts superoxide radical
into hydrogen per
can be rapidly decomposed into
(POD), catalase (CAT), ascorbate peroxidase (APX),
or in the ascorbate–glutathione cycle . Overexpres
sion of SOD was in positive correlation with stress tol
erance of many transgenic plants [8–10].
SOD can be classified into four groups: copper
zinc SOD (Cu/ZnSOD), iron SOD (FeSOD), man
ganese SOD (MnSOD), and nickel SOD (NiSOD).
MnSOD could be found in prokaryotic organisms as
well as in eukaryotes. NaSOD, putative MnSOD from
halophilic archaeon (
isolated in our previous work . By the experimen
tal verification, the NaSOD was expressed in coliba
cillus, and the tolerance of the colibacillus to a high
salt environment enhanced. Up to now, overexpres
sion of archaeon SOD in plants has not been reported.
) is a tremendously important food
crop and is particularly sensitive to salt stress. In this
was introduced into rice by
mediated transformation and proved to be a
MnSOD coding gene. Phenotypic changes and physi
ological parameters were measured, and the results
showed the transgenic rice plants were more tolerant
to salt stress than wildtype (WT) plants.
Heterologous Expression of a Halophilic Archaeon Manganese
Superoxide Dismutase Enhances Salt Tolerance in Transgenic Rice
, Y. H. Pan
, L. Y. An
, W. J. Yang
, L. G. Xu
, and C. Zhu
College of Life Sciences, Zhejiang University, Hangzhou 310058, P.R. China;
College of Life Sciences, China Jiliang University, Hangzhou 310018, P.R. China
School of Life Sciences, Taizhou University, Taizhou 317000, P.R. China
Received May 22, 2012
—In order to investigate new gene resource for enhancing rice tolerance to salt stress, manganese
superoxide dismutase gene from halophilic archaeon (
) was isolated and
L. cv. Nipponbare by
mediated transformation. The transfor
mants (L1 and L2) showed some
expression and increased total SOD and CAT activity, which
contributed to higher efficiency of ROS elimination under salt stress. The levels of superoxide anion radicals
and hydrogen peroxide (H
) were significantly decreased. In addition, they exhibited higher levels
of photosynthesis, whereas lower relative ion leakage and MDA content compared to wildtype plants.
Therefore, transgenic seedlings were phenotypically healthier, and heterologous expression of
could improve rice salt tolerance.
, superoxide dismutase, salt stress, transgenic rice
: CaMV—cauliflower mosaic virus; CAT—cata
—the minimum fluorescence yield;
—the maximum fluorescence yield;
glucuronidase; L1/L2—transgenic lines;
NBT—nitroblue tetrazolium chloride; —superoxide anion
radical; PCR—polymerase chain reaction; RTPCR—reverse
transcription–polymerase chain reaction; SOD—superoxide dis
mutase; WT—wild type.