Enhanced toxic metal accumulation in engineered bacterial cells expressing Arabidopsis thaliana phytochelatin synthase.
Phytochelatins (PCs) are metal-binding cysteine-rich peptides, enzymatically synthesized in plants and yeasts from glutathione in response to heavy metal stress by PC synthase (EC 2.3.2.15). In an attempt to increase the ability of bacterial cells to accumulate heavy metals, the Arabidopsis thaliana gene encoding PC synthase (AtPCS) was expressed in Escherichia coli. A marked accumulation of PCs was observed in vivo together with a decrease in the glutathione cellular content. When bacterial cells expressing AtPCS were placed in the presence of heavy metals such as cadmium or the metalloid arsenic, cellular metal contents were increased 20- and 50-fold, respectively. We discuss the possibility of using genes of the PC biosynthetic pathway to design bacterial strains or higher plants with increased abilities to accumulate toxic metals, and also arsenic, for use in bioremediation and/or phytoremediation processes.
Sauge-Merle
Sandrine
S
Direction des Sciences du Vivant, Département d'Ecophysiologie Végétale et de Microbiologie, Laboratoire d'Ecophysiologie de la Photosynthèse, Université de la Méditerranée CEA 1000, Saint-Paul-lez-Durance, France. sandrine.sauge-merle@cea.fr
Cuiné
Stéphan
S
Carrier
Patrick
P
Lecomte-Pradines
Catherine
C
Luu
Doan-Trung
DT
Peltier
Gilles
G
D019881:Aminoacyltransferases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005818:Genetic Engineering / Q000379:methods*; D019216:Metals, Heavy / Q000378:metabolism*
D003470:Culture Media; D019216:Metals, Heavy; D019881:Aminoacyltransferases; C093784:glutathione gamma-glutamylcysteinyltransferase