Expression of an Arabidopsis Ca2+/H+ antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation

J Plant Physiol. 2011 Jan 15;168(2):167-73. doi: 10.1016/j.jplph.2010.06.005. Epub 2010 Jul 14.


Phytoremediation is a cost-effective and minimally invasive technology to cleanse soils contaminated with heavy metals. However, few plant species are suitable for phytoremediation of metals such as cadmium (Cd). Genetic engineering offers a powerful tool to generate plants that can hyperaccumulate Cd. An Arabidopsis CAX1 mutant (CAXcd), which confers enhanced Cd transport in yeast, was ectopically expressed in petunia to evaluate whether the CAXcd expression would enhance Cd tolerance and accumulation in planta. The CAXcd-expressing petunia plants showed significantly greater Cd tolerance and accumulation than the controls. After being treated with either 50 or 100μM CdCl(2) for 6 weeks, the CAXcd-expressing plants showed more vigorous growth compared with controls, and the transgenic plants accumulated significantly more Cd (up to 2.5-fold) than controls. Moreover, the accumulation of Cd did not affect the development and morphology of the CAXcd-expressing petunia plants until the flowering and ultimately the maturing of seeds. Therefore, petunia has the potential to serve as a model species for developing herbaceous, ornamental plants for phytoremediation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antiporters / genetics
  • Antiporters / metabolism*
  • Biodegradation, Environmental
  • Cadmium / metabolism*
  • Cadmium / toxicity*
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / metabolism*
  • Petunia / drug effects*
  • Petunia / genetics
  • Petunia / metabolism*
  • Plants, Genetically Modified / drug effects
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism


  • Antiporters
  • Cation Transport Proteins
  • calcium-hydrogen antiporters
  • Cadmium