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Superoxide dismutases of chestnut leaves, Castanea sativa : Characterization and study of their involvement in natural leaf senescence
Author(s) -
Longa M. Angeles,
Río Luis A.,
Palma Josè M.
Publication year - 1994
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1994.tb05330.x
Subject(s) - superoxide dismutase , catalase , isozyme , senescence , peroxidase , hydrogen peroxide , biochemistry , chemistry , reactive oxygen species , superoxide , xanthine oxidase , polyacrylamide gel electrophoresis , enzyme , botany , biology , microbiology and biotechnology
Superoxide dismutases (SOD; EC 1.15.1.1) in chestnut ( Castanea sativa Mill., cv. 431) leaves were characterized by native polyacrylamide gel electrophoresis. The three molecular forms of SOD were distinguished from each other by their different sensitivity to cyanide and H 2 O 2 Three CuZn‐containing SODs were detected (CuZn‐SOD I, II. and III), and all the isozymes had a molecular mass of 33 kDa. CuZn‐SOD III was the most abundant isozyme. whereas CuZn‐SOD II was present in a minor amount. In leaves showing typical symptoms of senescence increases of 2.5‐. 7‐ and 4‐fold in the specific activities of CuZn‐SODs I, II, and III. respectively, were found. In addition, the pattern of the three isozymes was modified by the age of leaves, a rise in the CuZn‐SOD II and a decrease in the CuZn‐SOD 1 percentages being found in senescent leaves compared to green leaves. As to other activated oxygen‐related enzymes, an increase in the superoxide‐generating xanthine oxidase activity and a decline in both catalase and peroxidase activities during natural senescence of chestnut leaves were observed. Results obtained suggest that in natural senescence of chestnut leaves activated oxygen species are involved, and an overproduction of hydrogen peroxide and superoxide radicals probably takes place.