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Reactive oxygen species inhibit the succinate oxidation‐supported generation of membrane potential in wheat mitochondria
Author(s) -
Pastore Donato,
Laus Maura Nicoletta,
Di Fonzo Natale,
Passarella Salvatore
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02454-7
Subject(s) - mitochondrion , reactive oxygen species , biochemistry , mitochondrial ros , xanthine oxidase , chemistry , mersalyl , oxidative stress , paraquat , membrane potential , oxidative phosphorylation , microbiology and biotechnology , biophysics , biology , enzyme
In order to gain a first insight into the effects of reactive oxygen species (ROS) on plant mitochondria, we studied the effect of the ROS producing system consisting of xanthine plus xanthine oxidase on the rate of membrane potential (Δ Ψ ) generation due to either succinate or NADH addition to durum wheat mitochondria as monitored by safranin fluorescence. We show that the early ROS production inhibits the succinate‐dependent, but not the NADH‐dependent, Δ Ψ generation and oxygen uptake. This inhibition appears to depend on the impairment of mitochondrial permeability to succinate. It does not involve mitochondrial thiol groups sensitive to either mersalyl or N ‐ethylmaleimide and might involve both protein residues and/or membrane lipids, as suggested by the mixed nature. We propose that, during oxidative stress, early generation of ROS can affect plant mitochondria by impairing metabolite transport, thus preventing further substrate oxidation, Δ Ψ generation and consequent large‐scale ROS production.