Identification and characterization of Cd-induced peptides in Egeria densa (water weed): Putative role in Cd detoxification.
Egeria densa has ability to grow in heavy metal contaminated and polluted bodies of water. Shoots exposed to Cd at concentrations up to 300microM for 7 days showed a pronounced decrease in chlorophyll a and in total protein concentration. Thiol-containing compounds and low-molecular-weight polypeptides were detected in Cd-treated plant extracts by gel filtration chromatography. Two Cd-binding fractions, a thiol-enriched fraction and a non-thiol fraction with a lower molecular weight were identified in extracts by gel filtration. The main fraction of thiol-containing polypeptide, purified by gel filtration and anion-exchange chromatography had a molecular weight of approximately 10kDa. This peptide was characterized by a broad absorption band specific to mercaptide bonds and Cd-sensitive fluorescence emission of aromatic amino acid residues. Our results indicate that cadmium exposure of plants resulted in both a formation of thiol-enriched cadmium complexing peptides and a synthesis of low-molecular-weight metal chelators. The putative role of these compounds in Cd detoxification is discussed.
Malec
Przemysław
P
Department of Plant Physiology and Biochemistry, Jagiellonian University, Krakow, Poland.
Maleva
Maria G
MG
Prasad
M N V
MN
Strzałka
Kazimierz
K
D002104:Cadmium / Q000493:pharmacokinetics / Q000633:toxicity*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D031321:Hydrocharitaceae / Q000187:drug effects* / Q000378:metabolism*; D008658:Inactivation, Metabolic; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D002104:Cadmium