TY - JOUR
T1 - Analysis of phytochelatin complexes in the lead tolerant vetiver grass [Vetiveria zizanioides (L.)] using liquid chromatography and mass spectrometry
AU - Andra, Syam S.
AU - Datta, Rupali
AU - Sarkar, Dibyendu
AU - Saminathan, Sumathi K.M.
AU - Mullens, Conor P.
AU - Bach, Stephan B.H.
PY - 2009/7
Y1 - 2009/7
N2 - Ethylenediamene tetraacetic acid (EDTA) has been used to mobilize soil lead (Pb) and enhance plant uptake for phytoremediation. Chelant bound Pb is considered less toxic compared to free Pb ions and hence might induce less stress on plants. Characterization of possible Pb complexes with phytochelatins (PCn, metal-binding peptides) and EDTA in plant tissues will enhance our understanding of Pb tolerance mechanisms. In a previous study, we showed that vetiver grass (Vetiveria zizanioides L.) can accumulate up to 19,800 and 3350 mg Pb kg-1 dry weight in root and shoot tissues, respectively; in a hydroponics set-up. Following the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (with or without EDTA) in remediating Pb-contaminated soils from actual residential sites where Pb-based paints were used. The levels of total thiols, PCn, and catalase (an antioxidant enzyme) were measured in vetiver root and shoot following chelant-assisted phytostabilization. In the presence of 15 mM kg -1 EDTA, vetiver accumulated 4460 and 480 mg Pb kg-1 dry root and shoot tissue, respectively; that are 15- and 24-fold higher compared to those in untreated controls. Despite higher Pb concentrations in the plant tissues, the amount of total thiols and catalase activity in EDTA treated vetiver tissues was comparable to chelant unamended controls, indicating lowered Pb toxicity by chelation with EDTA. The identification of glutathione (referred as PC1) (m/z 308.2), along with chelated complexes like Pb-EDTA (m/z 498.8) and PC1-Pb-EDTA (m/z 805.3) in vetiver root tissue using electrospray tandem mass spectrometry (ES-MS) highlights the possible role of such species towards Pb tolerance in vetiver grass.
AB - Ethylenediamene tetraacetic acid (EDTA) has been used to mobilize soil lead (Pb) and enhance plant uptake for phytoremediation. Chelant bound Pb is considered less toxic compared to free Pb ions and hence might induce less stress on plants. Characterization of possible Pb complexes with phytochelatins (PCn, metal-binding peptides) and EDTA in plant tissues will enhance our understanding of Pb tolerance mechanisms. In a previous study, we showed that vetiver grass (Vetiveria zizanioides L.) can accumulate up to 19,800 and 3350 mg Pb kg-1 dry weight in root and shoot tissues, respectively; in a hydroponics set-up. Following the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (with or without EDTA) in remediating Pb-contaminated soils from actual residential sites where Pb-based paints were used. The levels of total thiols, PCn, and catalase (an antioxidant enzyme) were measured in vetiver root and shoot following chelant-assisted phytostabilization. In the presence of 15 mM kg -1 EDTA, vetiver accumulated 4460 and 480 mg Pb kg-1 dry root and shoot tissue, respectively; that are 15- and 24-fold higher compared to those in untreated controls. Despite higher Pb concentrations in the plant tissues, the amount of total thiols and catalase activity in EDTA treated vetiver tissues was comparable to chelant unamended controls, indicating lowered Pb toxicity by chelation with EDTA. The identification of glutathione (referred as PC1) (m/z 308.2), along with chelated complexes like Pb-EDTA (m/z 498.8) and PC1-Pb-EDTA (m/z 805.3) in vetiver root tissue using electrospray tandem mass spectrometry (ES-MS) highlights the possible role of such species towards Pb tolerance in vetiver grass.
KW - Catalase
KW - EDTA
KW - Glutathione
KW - Lead-based paint
KW - Liquid chromatography
KW - Mass spectrometry
KW - Phytochelatins
KW - Phytoremediation
KW - Thiols
KW - Vetiver
UR - http://www.scopus.com/inward/record.url?scp=65349160355&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65349160355&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2009.02.014
DO - 10.1016/j.envpol.2009.02.014
M3 - Article
C2 - 19282075
AN - SCOPUS:65349160355
SN - 0269-7491
VL - 157
SP - 2173
EP - 2183
JO - Environmental Pollution
JF - Environmental Pollution
IS - 7
ER -