Antioxidative defense to lead stress in subcellular compartments of pea root cells.
Lead, similar to other heavy metals and abiotic factors, causes many unfavorable changes at the subcellular and molecular levels in plant cells. An increased level of superoxide anion in Pisum sativum root cells treated with 1 mM Pb(NO3)2 evidenced oxidative stress conditions. We found increased activities of enzymatic components of the antioxidative system (catalase and superoxide dismutase) in the cytosol, mitochondrial and peroxisomal fractions isolated from root cells of Pisum sativum grown in modified Hoagland medium in the presence of lead ions (0.5 or 1 mM). Two isoenzyme forms of superoxide dismutase (Cu,Zn-SOD and Mn-SOD) found in different subcellular compartments of pea roots were more active in Pb-treated plants than in control. Increased amount of alternative oxidase accompanied by an increased activity of this enzyme was found in mitochondria isolated from lead-treated roots. These results show that plants storing excessive amounts of lead in roots defend themselves against the harmful oxidative stress caused by this heavy metal.
Malecka
A
A
Department of Biochemistry, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, Poland.
Jarmuszkiewicz
W
W
Tomaszewska
B
B
D000975:Antioxidants / Q000378:metabolism*; D015153:Blotting, Western; D002374:Catalase / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000378:metabolism; D007854:Lead / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D024101:Mitochondrial Proteins; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000378:metabolism; D018532:Pisum sativum / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D020675:Peroxisomes / Q000187:drug effects / Q000201:enzymology; D010940:Plant Proteins; D018517:Plant Roots / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D000099188:Alternative Oxidase
D000975:Antioxidants; D002374:Catalase; D007527:Isoenzymes; D007854:Lead; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D013481:Superoxides; D000099188:Alternative Oxidase