Ectopic expression of a maize calreticulin mitigates calcium deficiency-like disorders in sCAX1-expressing tobacco and tomato

Plant Mol Biol. 2012 Dec;80(6):609-19. doi: 10.1007/s11103-012-9970-6. Epub 2012 Sep 25.


Deregulated expression of an Arabidopsis H⁺/Ca²⁺ antiporter (sCAX1) in agricultural crops increases total calcium (Ca²⁺) but may result in yield losses due to Ca²⁺ deficiency-like symptoms. Here we demonstrate that co-expression of a maize calreticulin (CRT, a Ca²⁺ binding protein located at endoplasmic reticulum) in sCAX1-expressing tobacco and tomato plants mitigated these adverse effects while maintaining enhanced Ca²⁺ content. Co-expression of CRT and sCAX1 could alleviate the hypersensitivity to ion imbalance in tobacco plants. Furthermore, blossom-end rot (BER) in tomato may be linked to changes in CAX activity and enhanced CRT expression mitigated BER in sCAX1 expressing lines. These findings suggest that co-expressing Ca²⁺ transporters and binding proteins at different intracellular compartments can alter the content and distribution of Ca²⁺ within the plant matrix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiporters / genetics*
  • Antiporters / metabolism*
  • Calcium / metabolism*
  • Calreticulin / genetics*
  • Calreticulin / metabolism*
  • Cation Transport Proteins / genetics*
  • Cation Transport Proteins / metabolism*
  • Gene Expression
  • Genes, Plant
  • Plant Diseases / genetics
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Solanum lycopersicum / genetics
  • Solanum lycopersicum / metabolism
  • Tobacco / genetics
  • Tobacco / metabolism
  • Zea mays / genetics*
  • Zea mays / metabolism*


  • Antiporters
  • Calreticulin
  • Cation Transport Proteins
  • Plant Proteins
  • Recombinant Proteins
  • calcium-hydrogen antiporters
  • Calcium