Enhanced zinc and cadmium tolerance and accumulation in transgenic Arabidopsis plants constitutively overexpressing a barley gene (HvAPX1) that encodes a peroxisomal ascorbate peroxidase

Botany ◽  
2008 ◽  
Vol 86 (6) ◽  
pp. 567-575 ◽  
Author(s):  
Weifeng Xu ◽  
Weiming Shi ◽  
Feng Liu ◽  
Akihiro Ueda ◽  
Tetsuko Takabe
Keyword(s):  
Oxidative Stress ◽  
Transgenic Plants ◽  
Ascorbate Peroxidase ◽  
Transgenic Arabidopsis ◽  
Higher Plants ◽  
Cadmium Tolerance ◽  
Wild Type ◽  
Zinc Tolerance ◽  
Zinc Stress ◽  
Transgenic Arabidopsis Plants

Ascorbate peroxidase (APX) plays an important role in oxidative stress metabolism in higher plants. To determine the role of APX in protection against excessive-zinc-induced oxidative stress, transgenic Arabidopsis plants constitutively overexpressing a peroxisomal ascorbate peroxidase gene (HvAPX1) from barley were analyzed. In this study, we found that transgenic plants were more tolerant to zinc stress than wild-type plants. Under zinc stress, the concentration of hydrogen peroxide and malondialdehyde accumulation were higher in wild-type plants than in transgenic plants. Therefore, the mechanism of zinc tolerance in transgenic plants may be due to reduced oxidative stress damage. Under zinc stress, the activities of APX were significantly higher in transgenic plants than in wild-type plants. We also found that the zinc accumulation in the shoots were much higher in transgenic plants than in wild-type plants under zinc stress. In addition, we found that compared with wild-type plants, transgenic plants were more tolerant to excessive cadmium stress and accumulated more cadmium in shoots. These results suggest that HvAPX1 plays an important role in zinc and cadmium tolerance, and might be a candidate gene for developing high-biomass tolerant plants for phytoremediation of zinc- and cadmium-polluted environments.

Alleviation of ultraviolet-C-induced oxidative damage through overexpression of cytosolic ascorbate peroxidase

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Saurabh Saxena ◽  
Pankaj Joshi ◽  
Bernhard Grimm ◽  
Sandeep Arora
Keyword(s):  
Oxidative Stress ◽  
Transgenic Plants ◽  
Oxidative Damage ◽  
Ascorbate Peroxidase ◽  
Morphological Characters ◽  
Wild Type ◽  
Nicotiana Tabacum L ◽  
Cytosolic Ascorbate Peroxidase ◽  
Ultraviolet C ◽  
Uv C

AbstractExperiments were conducted to investigate the relationship between ultraviolet (UV) C-induced oxidative damage and the activity of ascorbate peroxidase (APX), using transgenic tobacco (Nicotiana tabacum L. cv. Petit Havana) plants overexpressing cytosolic APX gene (apx1). Transgenic plants having 2.3 fold higher total APX activity, as compared to the wild type plants, showed normal morphological characters. Exposure of 70-day-old plants to fixed intensity UV-C radiation caused an increase in the malondialdehyde (MDA) content in wild type as well as transgenic plants. However, the wild type plants showed significantly higher (p < 0.05) lipid peroxidation as compared to the transgenic plants. Higher proline accumulation was recorded in transgenic plants as compared to the wild type plants, after 24 hours of UV-C exposure. Although the ascorbate content decreased continuously with increasing exposure to UV-C radiation, yet the wild type plants exhibited higher ascorbate levels than the transgenic plants. A marked difference in H2O2 content, between the wild type and transgenic plants, was consistently observed up to 20 hours of UV-C exposure. A direct correlation of ascorbate, MDA and H2O2 levels was recorded with the extent of oxidative stress, signifying that these could be used as potential bio-marker molecules for oxidative stress. The results clearly demonstrate that overexpression of cytosolic APX can protect tobacco plants from UV-C-induced oxidative damage.

scholarly journals Degradation of trinitrotoluene by transgenic nitroreductase in Arabidopsis plants

2018 ◽  
Vol 64 (No. 8) ◽  
pp. 379-385 ◽  
Author(s):  
Zhu Bo ◽  
Han Hongjuan ◽  
Fu Xiaoyan ◽  
Li Zhenjun ◽  
Gao Jianjie ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Arabidopsis ◽  
Environmental Pollutant ◽  
Specific Rate ◽  
Wild Type Plant ◽  
Wild Type ◽  
Fresh Weight ◽  
Human Carcinogen ◽  
Specific Rate Constant ◽  
Nitroreductase Activity

The explosive 2,4,6-trinitrotoluene (TNT) is a highly toxic and persistent environmental pollutant. TNT is toxic to many organisms, it is known to be a potential human carcinogen, and is persistent in the environment. This study presents a system of phytoremediation by Arabidopsis plants developed on the basis of overexpression of NAD(P)H-flavin nitroreductase (NFSB) from the Sulfurimonas denitrificans DSM1251. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerance and a strikingly higher capacity to remove TNT from their media. The highest specific rate constant of TNT disappearance rate was 1.219 and 2.297 mL/g fresh weight/h for wild type and transgenic plants, respectively. Meanwhile, the nitroreductase activity in transgenic plant was higher than wild type plant. All this indicates that transgenic plants show significantly enhanced tolerances to TNT; transgenic plants also exhibit strikingly higher capabilities of removing TNT from their media and high efficiencies of transformation.

scholarly journals Enhanced Resistance to Fusarium graminearum in Transgenic Arabidopsis Plants Expressing a Modified Plant Thionin

2020 ◽  
Vol 110 (5) ◽  
pp. 1056-1066 ◽  
Author(s):  
Guixia Hao ◽  
Matthew G. Bakker ◽  
Hye-Seon Kim
Keyword(s):  
Transgenic Plants ◽  
Fusarium Graminearum ◽  
Transgenic Arabidopsis ◽  
Hyphal Growth ◽  
Marker Genes ◽  
Head Blight ◽  
Transgenic Expression ◽  
Transgenic Arabidopsis Plants ◽  
Enhanced Resistance ◽  
And Control

The fungal pathogen Fusarium graminearum causes Fusarium head blight (FHB) on wheat, barley, and other grains. FHB results in yield reductions and contaminates grain with trichothecene mycotoxins, which threaten food safety and food security. Innovative mechanisms for controlling FHB are urgently needed. We have previously shown that transgenic tobacco and citrus plants expressing a modified thionin (Mthionin) exhibited enhanced resistance toward several bacterial pathogens. The aim of this study was to investigate whether overexpression of Mthionin could be similarly efficacious against F. graminearum, and whether transgenic expression of Mthionin impacts the plant microbiome. Transgenic Arabidopsis plants expressing Mthionin were generated and confirmed. When challenged with F. graminearum, Mthionin-expressing plants showed less disease and fungal biomass in both leaves and inflorescences compared with control plants. When infiltrated into leaves, macroconidia of F. graminearum germinated at lower rates and produced less hyphal growth in Arabidopsis leaves expressing Mthionin. Moreover, marker genes related to defense signaling pathways were expressed at significantly higher levels after F. graminearum infection in Mthionin transgenic Arabidopsis plants. However, Mthionin expression did not appreciably alter the overall microbiome associated with transgenic plants grown under controlled conditions; across leaves and roots of Mthionin-expressing and control transgenic plants, only a few bacterial and fungal taxa differed, and differences between Mthionin transformants were of similar magnitude compared with control plants. In sum, our data indicate that Mthionin is a promising candidate to produce transgenic crops for reducing FHB severity and ultimately mycotoxin contamination.

scholarly journals Terpenoid Metabolism in Wild-Type and Transgenic Arabidopsis Plants

2003 ◽  
Vol 15 (12) ◽  
pp. 2866-2884 ◽  
Author(s):  
Asaph Aharoni ◽  
Ashok P. Giri ◽  
Stephan Deuerlein ◽  
Frans Griepink ◽  
Willem-Jan de Kogel ◽  
...  
Keyword(s):  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Transgenic Arabidopsis Plants ◽  
Terpenoid Metabolism

scholarly journals Inhibition of Catalase by Antisense RNA Increases Susceptibility to Oxidative Stress and Chilling Injury in Transgenic Tomato Plants

1999 ◽  
Vol 124 (4) ◽  
pp. 330-336 ◽  
Author(s):  
Kanogwan Kerdnaimongkol ◽  
William R. Woodson
Keyword(s):  
Oxidative Stress ◽  
Transgenic Plants ◽  
Stress Tolerance ◽  
Catalase Activity ◽  
Chilling Stress ◽  
Chilling Injury ◽  
Fold Increase ◽  
Transgenic Tomato ◽  
Wild Type ◽  
Leaf Extracts

Transgenic tomatoes (Lycopersicon esculentum Mill. `Ohio 8245') expressing an antisense catalase gene (ASTOMCAT1) were used to test the hypothesis that modification of the reactive oxygen species scavenging mechanism in plants can lead to changes in oxidative stress tolerance. A 2- to 8-fold reduction in total catalase activity was detected in the leaf extracts of transformants. A 2-fold increase in levels of H2O2 was observed in the transgenic plants with reduced catalase activity. Electrophoretic characterization of multiple catalase isoforms revealed the specific suppression of CAT1 in transgenic plants. Homozygous plants carrying the antisense catalase transgene were used to study the effect of alteration in the expression of catalase on stress tolerance. Transgenic plants treated with 3% H2O2 showed visible damage within 24 hours and subsequently died. In contrast, wild-type and azygous control plants recovered from the treatment. Transgenic plants did not survive 4 °C chilling stress compared to control wild-type and azygous lines. Physiological analysis of these plants indicated that suppression of catalase activity in transgenic tomato led to enhanced sensitivity to oxidative stress. Our data support a role for catalase in oxidative stress defense system in tomato.

scholarly journals Overexpression of Cytosolic Ascorbate Peroxidase in Tomato Confers Tolerance to Chilling and Salt Stress

2005 ◽  
Vol 130 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Yueju Wang ◽  
Michael Wisniewski ◽  
Richard Meilan ◽  
Minggang Cui ◽  
Robert Webb ◽  
...  
Keyword(s):  
Salt Stress ◽  
Transgenic Plants ◽  
Ascorbate Peroxidase ◽  
Higher Plants ◽  
Visual Assessment ◽  
Kanamycin Resistance ◽  
Leaf Damage ◽  
Cytosolic Ascorbate Peroxidase ◽  
Transgenic Lines

Ascorbate peroxidase (APX) plays an important role in the metabolism of hydrogen peroxide in higher plants, affording them protection against oxidative stress. We studied the effect of overexpressing a cytosolic ascorbate peroxidase (cAPX) gene—derived from pea (Pisum sativum L.)—in transgenic tomato plants (Lycopersicon esculentum L.). Transformants were selected in vitro using kanamycin resistance and confirmed by polymerase chain reaction (PCR) and northern analyses. An APX native-gel assay indicated that, in the absence of stress, APX activity in transgenic plants was several times greater than that measured in wild-type (WT) plants. Several independently transformed lines were propagated and evaluated for resistance to chilling and salt stress. After placing seeds at 9 °C for 5 weeks, percent germination was greater for seeds obtained from transgenic lines (26% to 37%) compared to the WT (3%). Plants from transgenic lines also had lower electrolyte leakage (20% to 23%) than WT (44%) after exposure to 4 °C. Visual assessment of transgenic and WT lines exposed to salinity stress (200 or 250 mm) confirmed that overexpression of APX minimized leaf damage. Moreover, APX activity was nearly 25- and 10-fold higher in the leaves of transgenic plants in response to chilling and salt stresses, respectively. Our results substantiate that increased levels of APX activity brought about by overexpression of a cytosolic APX gene may play an important role in ameliorating oxidative injury induced by chilling and salt stress.

scholarly journals Enhanced Tolerance to Oxidative Stress in Transgenic Arabidopsis Plants Expressing Proteins of Unknown Function

2008 ◽  
Vol 148 (1) ◽  
pp. 280-292 ◽  
Author(s):  
Song Luhua ◽  
Sultan Ciftci-Yilmaz ◽  
Jeffery Harper ◽  
John Cushman ◽  
Ron Mittler
Keyword(s):  
Oxidative Stress ◽  
Unknown Function ◽  
Transgenic Arabidopsis ◽  
Transgenic Arabidopsis Plants
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