ISSN 10214437, Russian Journal of Plant Physiology, 2013, Vol. 60, No. 3, pp. 330–336. © Pleiades Publishing, Ltd., 2013.
With the development of greenhouse and bigarch
shelter, secondary soil salinization resulted from inef
ficient rotation, irrigation, and excessive applying fer
tilizer becomes one of the major factors limiting agri
cultural production in China. Sodium is one of the
major toxic ions in saline soils harmful to plants. To
cope with salt stress, plants have evolved a variety of
adaptation mechanisms .
compartmentation are two important mechanisms for
plants. Compartmentation of
into vacuoles could
be accomplished by the action of the
porter in the vacuolar membranes. Meanwhile, the
function of the
antiporter in the plasma
membrane (NHA) is to extrude
from the cells.
The first NHA gene of higher plant plasma mem
brane was cloned from
a series of plasma membrane
ing genes have been identified and cloned, such as
from rice [3, 4],
sea grass ,
from reeds plant,
from salty grass
This text was submitted by the authors in English.
These authors contributed equally to this work.
from tomato. Moreover, the overex
in transgenic plants could signifi
cantly improve salt tolerance of
ever, limited information is available about
horticultural plants, particularly cucumber plants.
Cucumber is an important horticultural crop and is
mainly cultivated in a greenhouse where secondary
soil salinization threatens to become, or already is,
and became a problem in China. Some species of
cucumber show strong salt tolerance. More studies
should be done to evaluate the key genes involved in
cucumber salt tolerance. In this study, therefore, we
cloned the new plasma membrane
from cucumber, analyzed its sequence, expression in
mutant yeast, and expression patterns under salt stress.
This work may pave the way for improving the cucumber
salt tolerance strategies by means of genetic engineering.
MATERIALS AND METHODS
Seeds of cucumber (
cultivar Shenlv72 obtained from Shanghai Jiao Tong
University were germinated and grown in perlite in
plant chamber (16h photoperiod,
). When the
first pair of cucumber euphylla was fully expanded, for
salt treatments, the cucumber seedlings were ran
domly selected and then grown in 0.5strength Hoag
land solutions containing 0, 25, 50, or 100 mM NaCl
Cloning and Characterization of a Plasma Membrane Na
Antiporter Gene from
, Z. Li
, R. Rui
, G. S. Fan
, and K. W. Lin
College of Landscape Architecture, Southwest Forestry University, Kunming 650224, China;
fax: +860871 3863023; email: firstname.lastname@example.org
College of Horticulture, Northwest A&F University, Yangling, Shanxi 712100, China
College of Civil Engineering, Southwest Forestry University, Kunming 650224, China
Received May 16, 2012
—A plasma membrane Na
antiporter gene (
) was separated from cucumber (
L.) plants by RTPCR and RACE methods. Sequence analysis indicated that the fulllength
cDNA was 3638 bp long with an open reading frame of 3435 bp long encoding a protein of 1145 amino acids.
The deduced protein contained conserved structural domains and shared a high similarity with plasma mem
brane type Na
antiporters from other plants. TMpred prediction showed that
had 11 trans
membrane domains. As shown by RTPCR, the expression of
was tissuespecific and increased in
the root but decreased in the leaves with increasing NaCl concentration. In addition, expression of
in ATX3 mutant yeast could grow on medium containing NaCl and enhanced AXT3 salt tolerance. These
results suggest that the
plays a key role in cucumber plants under salt stress.
Keywords: Cucumis sativus
, plasma membrane Na
antiporter gene (
), cDNA cloning, yeast
Amplification of cDNA Ends.