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The impact of oxidative stress on Arabidopsis mitochondria
Author(s) -
Sweetlove L.J.,
Heazlewood J.L.,
Herald V.,
Holtzapffel R.,
Day D.A.,
Leaver C.J.,
Millar A.H.
Publication year - 2002
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2002.01474.x
Subject(s) - biochemistry , oxidative stress , mitochondrion , antimycin a , alternative oxidase , aconitase , menadione , nadh dehydrogenase , thioredoxin , atp synthase , biology , chemistry , protein disulfide isomerase , thioredoxin reductase , lipoic acid , enzyme , antioxidant , mitochondrial dna , gene
Summary Treatment of Arabidopsis cell culture for 16 h with H 2 O 2 , menadione or antimycin A induced an oxidative stress decreasing growth rate and increasing DCF fluorescence and lipid peroxidation products. Treated cells remained viable and maintained significant respiratory rates. Mitochondrial integrity was maintained, but accumulation of alternative oxidase and decreased abundance of lipoic acid‐containing components during several of the treatments indicated oxidative stress. Analysis of the treatments was undertaken by IEF/SDS‐PAGE, comparison of protein spot abundances and tandem mass spectrometry. A set of 25 protein spots increased >3‐fold in H 2 O 2 /menadione treatments, a subset of these increased in antimycin A‐treated samples. A set of 10 protein spots decreased significantly during stress treatments. A specific set of mitochondrial proteins were degraded by stress treatments. These damaged components included subunits of ATP synthase, complex I, succinyl CoA ligase, aconitase, and pyruvate and 2‐oxoglutarate dehydrogenase complexes. Nine increased proteins represented products of different genes not found in control mitochondria. One is directly involved in antioxidant defense, a mitochondrial thioredoxin‐dependent peroxidase, while another, a thioredoxin reductase‐dependent protein disulphide isomerase, is required for protein disulfide redox homeostasis. Several others are generally considered to be extramitochondrial but are clearly present in a highly purified mitochondrial fraction used in this study and are known to play roles in stress response. Using H 2 O 2 as a model stress, further work revealed that this treatment induced a protease activity in isolated mitochondria, putatively responsible for the degradation of oxidatively damaged mitochondrial proteins and that O 2 consumption by mitochondria was significantly decreased by H 2 O 2 treatment.