Expression of phytochelatin synthase from aquatic macrophyte Ceratophyllum demersum L. enhances cadmium and arsenic accumulation in tobacco

Plant Cell Rep. 2012 Sep;31(9):1687-99. doi: 10.1007/s00299-012-1283-3. Epub 2012 May 22.

Abstract

Phytochelatin synthase (PCS), the key enzyme involved in heavy metal detoxification and accumulation has been used from various sources to develop transgenic plants for the purpose of phytoremediation. However, some of the earlier studies provided contradictory results. Most of the PCS genes were isolated from plants that are not potential metal accumulators. In this study, we have isolated PCS gene from Ceratophyllum demersum cv. L. (CdPCS1), a submerged rootless aquatic macrophyte, which is considered as potential accumulator of heavy metals. The CdPCS1 cDNA of 1,757 bp encodes a polypeptide of 501 amino acid residues and differs from other known PCS with respect to the presence of a number of cysteine residues known for their interaction with heavy metals. Complementation of cad1-3 mutant of Arabidopsis deficient in PC (phytochelatin) biosynthesis by CdPCS1 suggests its role in the synthesis of PCs. Transgenic tobacco plants expressing CdPCS1 showed several-fold increased PC content and precursor non-protein thiols with enhanced accumulation of cadmium (Cd) and arsenic (As) without significant decrease in plant growth. We conclude that CdPCS1 encodes functional PCS and may be part of metal detoxification mechanism of the heavy metal accumulating plant C. demersum.

Key message: Heterologous expression of PCS gene from C. demersum complements Arabidopsis cad1-3 mutant and leads to enhanced accumulation of Cd and As in transgenic tobacco.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / drug effects
  • Amino Acid Sequence
  • Aminoacyltransferases / chemistry
  • Aminoacyltransferases / genetics
  • Aminoacyltransferases / metabolism*
  • Aquatic Organisms / drug effects
  • Aquatic Organisms / enzymology*
  • Arabidopsis / drug effects
  • Arabidopsis / metabolism
  • Arsenic / metabolism*
  • Arsenic / toxicity
  • Cadmium / metabolism*
  • Cadmium / toxicity
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Plant / drug effects
  • Genetic Complementation Test
  • Magnoliopsida / drug effects
  • Magnoliopsida / enzymology*
  • Molecular Sequence Data
  • Mutation / genetics
  • Nicotiana / drug effects
  • Nicotiana / genetics*
  • Nicotiana / growth & development
  • Nicotiana / metabolism*
  • Peptides / metabolism
  • Phylogeny
  • Phytochelatins / metabolism
  • Plants, Genetically Modified
  • Sequence Alignment
  • Sulfhydryl Compounds / metabolism

Substances

  • Peptides
  • Sulfhydryl Compounds
  • Cadmium
  • Phytochelatins
  • Aminoacyltransferases
  • glutathione gamma-glutamylcysteinyltransferase
  • Arsenic