Planta

, Volume 225, Issue 5, pp 1255–1264

Overexpression of monodehydroascorbate reductase in transgenic tobacco confers enhanced tolerance to ozone, salt and polyethylene glycol stresses

  • Amin Elsadig Eltayeb
  • Naoyoshi Kawano
  • Ghazi Hamid Badawi
  • Hironori Kaminaka
  • Takeshi Sanekata
  • Toshiyuki Shibahara
  • Shinobu Inanaga
  • Kiyoshi Tanaka
Original Article

DOI: 10.1007/s00425-006-0417-7

Cite this article as:
Eltayeb, A.E., Kawano, N., Badawi, G.H. et al. Planta (2007) 225: 1255. doi:10.1007/s00425-006-0417-7

Abstract

Ascorbate (AsA) is a major antioxidant and free-radical scavenger in plants. Monodehydroascorbate reductase (MDAR; EC 1.6.5.4) is crucial for AsA regeneration and essential for maintaining a reduced pool of AsA. To examine whether an overexpressed level of MDAR could minimize the deleterious effects of environmental stresses, we developed transgenic tobacco plants overexpressing Arabidopsis thaliana MDAR gene (AtMDAR1) in the cytosol. Incorporation of the transgene in the genome of tobacco plants was confirmed by PCR and Southern-blot analysis and its expression was confirmed by Northern- and Western-blot analyses. These transgenic plants exhibited up to 2.1-fold higher MDAR activity and 2.2-fold higher level of reduced AsA compared to non-transformed control plants. The transgenic plants showed enhanced stress tolerance in term of significantly higher net photosynthesis rates under ozone, salt and polyethylene glycol (PEG) stresses and greater PSII effective quantum yield under ozone and salt stresses. Furthermore, these transgenic plants exhibited significantly lower hydrogen peroxide level when tested under salt stress. These results demonstrate that an overexpressed level of MDAR properly confers enhanced tolerance against ozone, salt and PEG stress.

Keywords

Ascorbate Monodehydroascorbate reductase Oxidative stress Reactive oxygen species Vitamin C 

List of abbreviations

APX

Ascorbate peroxidase

AsA

Ascorbate

DHA

Dehydroascorbate

DHAR

Dehydroascorbate reductase

GSH

Glutathione

MDAR

Monodehydroascorbate reductase

MDHA

Monodehydroascorbate

PEG

Polyethylene glycol

ROS

Reactive oxygen species

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Amin Elsadig Eltayeb
    • 1
    • 6
  • Naoyoshi Kawano
    • 2
  • Ghazi Hamid Badawi
    • 3
  • Hironori Kaminaka
    • 1
  • Takeshi Sanekata
    • 4
  • Toshiyuki Shibahara
    • 5
  • Shinobu Inanaga
    • 2
  • Kiyoshi Tanaka
    • 1
  1. 1.Laboratory of Plant Biotechnology, Faculty of AgricultureTottori UniversityTottoriJapan
  2. 2.Japan International Research Center for Agricultural Sciences IbarakiJapan
  3. 3.Department of Agronomy, Faculty of AgricultureUniversity of KhartoumShambatSudan
  4. 4.Laboratory of Veterinary Infectious Disease, Faculty of AgricultureTottori UniversityTottoriJapan
  5. 5.Division of Laboratory Animal Science, Research Center for Bioscience and TechnologyTottori UniversityTottoriJapan
  6. 6.Agricultural Research and Technology CorporationWad MedaniSudan

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