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Plant Gene and Trait 2012, Vol.3, No.2, 6
-
12
http://pgt.sophiapublisher.com
6
A Letter Open Access
Studies on Salt Tolerance of Transgenic Sweetpotato which harbors two Genes
Expressing CuZn Superoxide Dismutase and Ascorbate Peroxidase with the
Stress-inducible SWPA2 Promoter
Xin Wang
1
, Xiaoming Guo
1
, Qiang Li
1
, Zhonghou Tang
1
, Sangsoo Kwak
2
, Daifu Ma
1
1. Sweetpotato Research Institute, Chinese Academy of Agricultural Sciences/Jiangsu Xuzhou Sweetpotato Research Center, XuZhou, 221121, R.P. China
2. Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806, Korea
Corresponding author email:
daifuma@163.com;
Authors
Plant Gene and Trait, 2012, Vol.3, No.2 doi: 10.5376/pgt.2012.03.0002
Received: 19, Sep., 2010
Accepted: 28, Nov., 2011
Published: 07, Dec., 2011
This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Wang et al., 2011, Studies on Salt Tolerance of Transgenic Sweetpotato which Harbors Two Genes Expressing CuZn Superoxide Dismutase and Ascorbate Peroxidase with the
Stress-inducible SWPA2 Promoter, Plant Gene and Trait, Vol.3, No.2 6-12 (doi: 10.5376/pgt.2012.03.0002)
Abstract
In this study, some physiological indexes of leaves in transgenic sweetpotato (
Ipomoea batatas
L. cv. Yulmi), which
harbors two genes CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) genes, with the stress-inducible SWPA2
promoter were evaluated under different concentrations of NaCl treatment. The results showed that physiological indexes were no
remarkable differences without NaCl stress between the transgenic sweetpotato (TS) and the non-transformed sweet potato (NS). The
activity of superoxide dismutase (SOD), ascorbate peroxidease (APX), peroxidase (POD) and catalase (CAT) in leaves of TS was
always higher than NS under the same NaCl stress, respectively, and when the concentration NaCl with 100 mmol/L, the enzyme
activities was the most significant difference especially. On the other hand, the root length of TS was longer than that of NS. And the
decline range of chlorophyll and malonaldehyde (MDA) content in leaves of TS was lower than that of NS. All these results indicated
that transgenic sweetpotato had the resistance to salt tolerance. Therefore, there would be a great significance in efficiently utilizing
saline land and alleviating the energy crisis by developing and planting transgenic sweetpotato plants with salt tolerance.
Keywords
Transgenic sweetpotato; CuZnSOD; APX; Salt tolerance
Background
There are a lot of wasteland in the coastal areas, the
north and northwest of China because of the soil
salinization. Sweetpotato (
Ipomoea batatas
(L.) Lam.)
as an important food, feed, industrial raw material and
new energy source crops, is a strong applicability crop.
Therefore, there would be a great significance in
efficiently utilizing saline land and alleviating the
energy crisis by developing and planting transgenic
sweetpotato plants with salt tolerance.
Under environment stresses, the antioxidant defense
system of plants will play a coordinating role to
effectively scavenge the superoxide radicals, H
2
O
2
,
singlet oxygen and hydroxyl free radicals, aviod lipid
peroxidation, and prevent the cell membrane from
harm. SOD, CAT, POD and APX play an important
role in removing excess reactive oxygen species (ROS)
of cellular, among them, two key ROS detoxification
enzymes in the chloroplast are SOD and APX. SOD is
the first substance in common defense response
against abiotic stresses and catalyzes the dismutation
of two molecules of the superoxide anion radical into
oxygen and hydrogen peroxide, and APX reduces
hydrogen peroxide to water by utilizing ascorbate as
an electron donor (Mittler, 2002). Recently, SOD
genes have been overexpressed in plants to improve
their tolerance to environmental stresses (Yu et al.,
1999; Kwon et al., 2002). Liu et al (2003) used
transgenic potato plants as the materials to study the
changes of active oxygen metabolism and protective
enzyme at different NaCl concentrations stress, the
results showed that the transgenic potato with
CuZn-SOD gene had a strong antioxidant capacity and
a potential ability in salt tolerance. The previous work
demonstrated that transgenic plant expressing the
genes of APX improved its tolerance to oxidative
stress (Kornyeyev et al., 2001). Transgenic tobacco