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Trace element distribution and species fractionation in Brassica napus plant
Author(s) -
Mestek Oto,
Polák Jan,
Juříček Martin,
Karvánková Pavla,
Koplík Richard,
Šantrûček Jiří,
Kodíček Milan
Publication year - 2007
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1237
Subject(s) - chemistry , shoot , fractionation , metal , trace element , zinc , dry weight , nuclear chemistry , metal ions in aqueous solution , botany , chromatography , organic chemistry , biology
Trace element status in the parts of the rape plant (roots, shoots, seeds) has been investigated. Roots are able to accumulate large amounts of metals: approximately 2000 mg kg −1 Fe; 120 mg kg −1 Mn; 30 mg kg −1 Zn; 2–8 mg kg −1 As, Cr, Ni, Cu and Pb; 0.3–1 mg kg −1 Co, Mo and Cd; and 0.1 mg kg −1 Ag and Tl (on a dry weight basis). However, the transfer of metals into shoots is limited. The ratios of element contents in shoots and roots are: 10–30% for Ag, Co, Cr, Fe, Mn, Ni and Pb; 50–100% for As, Cd, Cu and Zn; and > 110% for Tl and Mo. The transfer of elements into the seeds is even lower except for Cu, Zn, Mo and Tl. The ratios of element contents in seeds and roots are: < 20% for Ag, As, Cd, Co, Cr, Fe and Pb; 20–60% for Cu, Mn and Ni; 90% for Tl; and 180–190% for Mo and Zn. The soluble portion of Fe, As and Pb compounds in Tris–HCl buffer (pH = 7.5) represents < 10% of total content, whereas that of other elements ranges between 10 and 60%. Extracts of all three parts of plant were submitted to SEC/ICP‐MS analysis. While the majority of Co, Cu, Mo, Mn, Ni and Zn compounds is bound in a low‐molecular‐weight fraction (1–2 kDa), that of As, Ag, Cr, Tl and Pb is present as metal ions or labile complexes. There is one exception: Tl in seed extract is found in three regions of M r approximately 80, 5 and 2 kDa, respectively. The recovery of chromatographic separation of Tl compounds is approximately 100%. The low‐molecular‐weight fraction of the seed extract was isolated on preparative‐scale SEC and refined by immobilized metal affinity chromatography. The isolated ligands contain large amounts of Cys, Asx, Glx and Gly. Moreover S ‐carboxymethylcysteine was found. No phytochelatins were found by MALDI‐MS analysis. Copyright © 2007 John Wiley & Sons, Ltd.