Tolerance analysis of chloroplast OsCu/Zn-SOD overexpressing rice under NaCl and NaHCO3 stress

PLoS One. 2017 Oct 11;12(10):e0186052. doi: 10.1371/journal.pone.0186052. eCollection 2017.


The 636-bp-long cDNA sequence of OsCu/Zn-SOD (AK059841) was cloned from Oryza sativa var. Longjing11 via reverse transcription polymerase chain reaction (RT-PCR). The encoded protein comprised of 211 amino acids is highly homologous to Cu/Zn-SOD proteins from tuscacera rice and millet. Quantitative RT-PCR revealed that in rice, the level of OsCu/Zn-SOD gene expression was lowest in roots and was highest in petals and during the S5 leaf stage. Moreover, the expression level of OsCu/Zn-SOD gene expression decreased during the L5 leaf stage to maturity. The level of OsCu/Zn-SOD gene expression, however, was increased under saline-sodic stress and NaHCO3 stress. Germination tests under 125, 150, and 175 mM NaCl revealed that OsCu/Zn-SOD-overexpressing lines performed better than the non-transgenic (NT) Longjing11 lines in terms of germination rate and height. Subjecting seedlings to NaHCO3 and water stress revealed that OsCu/Zn-SOD-overexpressing lines performed better than NT in terms of SOD activity, fresh weight, root length, and height. Under simulated NaHCO3 stress, OsCu/Zn-SOD-overexpressing lines performed better than NT in terms of survival rate (25.19% > 6.67%) and yield traits (average grain weight 20.6 > 18.15 g). This study showed that OsCu/Zn-SOD gene overexpression increases the detoxification capacity of reactive oxygen species in O. sativa and reduces salt-induced oxidative damage. We also revealed the regulatory mechanism of OsCu/Zn-SOD enzyme in saline-sodic stress resistance in O. sativa. Moreover, we provided an experimental foundation for studying the mechanism of OsCu/Zn-SOD enzymes in the chloroplast.

MeSH terms

  • Adaptation, Physiological / drug effects*
  • Amino Acid Sequence
  • Chloroplasts / enzymology*
  • Cloning, Molecular
  • Gene Expression Regulation, Plant / drug effects
  • Genetic Vectors / metabolism
  • Green Fluorescent Proteins / metabolism
  • Oryza / drug effects
  • Oryza / enzymology*
  • Oryza / genetics
  • Oryza / physiology*
  • Phylogeny
  • Plants, Genetically Modified
  • Reactive Oxygen Species / metabolism
  • Real-Time Polymerase Chain Reaction
  • Seedlings / drug effects
  • Seedlings / growth & development
  • Sequence Alignment
  • Sodium Bicarbonate / pharmacology*
  • Sodium Chloride / pharmacology*
  • Stress, Physiological / drug effects*
  • Subcellular Fractions / drug effects
  • Subcellular Fractions / metabolism
  • Superoxide Dismutase-1 / metabolism*


  • Reactive Oxygen Species
  • Green Fluorescent Proteins
  • Sodium Chloride
  • Sodium Bicarbonate
  • Superoxide Dismutase-1

Grant support

This work was supported by the Fundamental Research Funds for the Central Universities (Grant no. 2572016EAJ6); The National Key Research and Development Program of China (2016YFC0501203); The Heilongjiang Postdoctoral Scientific Research Developmental Fund (LBH408 Q15004) and the Program for Chang jiang Scholars and Innovative Research Team in University (IRT13053).