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Origin of cadmium‐induced reactive oxygen species production: mitochondrial electron transfer versus plasma membrane NADPH oxidase
Author(s) -
Heyno Eiri,
Klose Cornelia,
KriegerLiszkay Anja
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2008.02512.x
Subject(s) - reactive oxygen species , chemistry , superoxide , nadph oxidase , hydrogen peroxide , biochemistry , mitochondrion , mitochondrial ros , biophysics , biology , enzyme
Summary• Cadmium (Cd 2+ ) is an environmental pollutant that causes increased reactive oxygen species (ROS) production. To determine the site of ROS production, the effect of Cd 2+ on ROS production was studied in isolated soybean ( Glycine max ) plasma membranes, potato ( Solanum tuberosum ) tuber mitochondria and roots of intact seedlings of soybean or cucumber ( Cucumis sativus ). • The effects of Cd 2+ on the kinetics of superoxide (), hydrogen peroxide (H 2 O 2 ) and hydroxyl radical ( • OH) generation were followed using absorption, fluorescence and spin‐trapping electron paramagnetic resonance spectroscopy. • In isolated plasma membranes, Cd 2+ inhibited production. This inhibition was reversed by calcium (Ca 2+ ) and magnesium (Mg 2+ ). In isolated mitochondria, Cd 2+ increased and H 2 O 2 production. In intact roots, Cd 2+ stimulated H 2 O 2 production whereas it inhibited and • OH production in a Ca 2+ ‐reversible manner. • Cd 2+ can be used to distinguish between ROS originating from mitochondria and from the plasma membrane. This is achieved by measuring different ROS individually. The immediate (≤ 1 h) consequence of exposure to Cd 2+ in vivo is stimulation of ROS production in the mitochondrial electron transfer chain and inhibition of NADPH oxidase activity in the plasma membrane.