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Evaluation of the influence of arsenic species on the nitrogen metabolism of a model angiosperm: nasturtium, Tropaeolum majus
Author(s) -
Schmidt AnneChristine,
Mattusch Jürgen,
Reisser Werner,
Wennrich Rainer
Publication year - 2005
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.869
Subject(s) - arsenic , chemistry , arsenite , nitrogen , metabolism , nitrogen cycle , amino acid , tracer , nitrate , biochemistry , environmental chemistry , botany , organic chemistry , biology , physics , nuclear physics
How the various organic and inorganic arsenic species affect the nitrogen metabolism of a model plant, Tropaeolum majus , was studied in order to evaluate the toxicological impact of the various chemical forms of arsenic. For this purpose, the effects on the (a) entire nitrogen pool, (b) protein fraction, and (c) non‐protein fraction were distinguished. The arsenic‐dependent effects on the nitrogen cycle were assessed by using 15 N‐labelled KNO 3 as a nutritive substance and optical emission spectroscopy to analyse how 15 N is incorporated into the nitrogen cycle. In addition to the 15 N‐tracer experiments, the uptake and metabolization of the arsenic compounds were examined. The work shows that biochemical indicator systems like 15 N‐tracer studies are able to characterize the degree of the influence of metabolic processes by arsenic species. For example, the incorporated 15 N concentration decreased linearly and independently of the 15 N fraction with increasing dimethylarsinate (DMA) concentrations. This behaviour indicates that DMA has prevented the uptake of 15 N and hence the formation of amino acids and proteins. Arsenite‐treated plants exhibited an elevated concentration of non‐protein 15 N, which could be an indication either for a stimulated uptake of nitrate or for an interrupted amino acid/protein synthesis. Copyright © 2005 John Wiley & Sons, Ltd.