Enhanced stress-tolerance of transgenic tobacco plants expressing a human dehydroascorbate reductase gene

J Plant Physiol. 2003 Apr;160(4):347-53. doi: 10.1078/0176-1617-00926.


To analyze the physiological role of dehydroascorbate reductase (DHAR, EC catalyzing the reduction of DHA to ascorbate in environmental stress adaptation, T1 transgenic tobacco (Nicotiana tabacum cv. Xanthi) plants expressing a human DHAR gene in chloroplasts were biochemically characterized and tested for responses to various stresses. Fully expanded leaves of transgenic plants had about 2.29 times higher DHAR activity (units/g fresh wt) than non-transgenic (NT) plants. Interestingly, transgenic plants also showed a 1.43 times higher glutathione reductase activity than NT plants. As a result, the ratio of AsA/DHA was changed from 0.21 to 0.48, even though total ascorbate content was not significantly changed. When tobacco leaf discs were subjected to methyl viologen (MV) at 5 mumol/L and hydrogen peroxide (H2O2) at 200 mmol/L, transgenic plants showed about a 40% and 25% reduction in membrane damage relative to NT plants, respectively. Furthermore, transgenic seedlings showed enhanced tolerance to low temperature (15 degrees C) and NaCl (100 mmol/L) compared to NT plants. These results suggest that a human derived DHAR properly works for the protection against oxidative stress in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Cold Temperature
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Oxidoreductases / genetics*
  • Paraquat / pharmacology
  • Plant Leaves / drug effects
  • Plants, Genetically Modified / genetics*
  • Plants, Genetically Modified / metabolism
  • Plants, Genetically Modified / physiology
  • Sodium Chloride / administration & dosage
  • Tobacco / genetics*
  • Tobacco / metabolism
  • Tobacco / physiology


  • Sodium Chloride
  • Hydrogen Peroxide
  • Oxidoreductases
  • glutathione dehydrogenase (ascorbate)
  • Paraquat