Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans

Int J Mol Sci. 2016 Feb 19;17(2):257. doi: 10.3390/ijms17020257.


Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS), an enzyme involved in the biosynthesis of phytochelatins (PCs), plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP) and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1) is transcriptionally non-responsive to a chronic (48 h) insult of high levels of zinc (500 μM) or acute (3 h) exposures to high levels of cadmium (300 μM). However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748) knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans.

Keywords: C. elegans; X-ray fluorescence microscopy; nematode; phytochelatin synthase.

Publication types

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

MeSH terms

  • Aminoacyltransferases / genetics*
  • Animals
  • Animals, Genetically Modified
  • Cadmium / analysis*
  • Caenorhabditis elegans / enzymology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans Proteins / genetics*
  • Environmental Pollutants / analysis*
  • Gene Deletion*
  • Phytochelatins / biosynthesis
  • Spectrometry, X-Ray Emission / instrumentation
  • Synchrotrons
  • Zinc / analysis


  • Caenorhabditis elegans Proteins
  • Environmental Pollutants
  • Cadmium
  • Phytochelatins
  • Aminoacyltransferases
  • phytochelatin synthase, C elegans
  • Zinc