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SUPEROXIDE DISMUTASE ACTIVITY IN PERIDINIUM GATUNENSE IN LAKE KINNERET: EFFECT OF LIGHT REGIME AND CARBON DIOXIDE CONCENTRATION 1
Author(s) -
Butow Barbara J.,
Wynne David,
TelOr Elisha
Publication year - 1997
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.0022-3646.1997.00787.x
Subject(s) - superoxide dismutase , biology , acclimatization , bloom , carbon dioxide , biochemistry , photosynthesis , botany , enzyme , ecology
The activity of superoxide dismutase (EC 1.15.1.1, superoxide: superoxide oxidoreductase) (SOD) was determined in Peridinium gatunense Lemm. under natural and controlled conditions. SOD activity increased toward the end of the spring algal bloom in Lake Kinneret simultaneously with maximal photosynthetic activity and conditions of elevated ambient stress such as high irradiance. Activity staining of native polyacrylamide gel electrophoresis gels of bloom samples showed a similar pattern to the spectrophotometrically measured SOD. Both Mn SOD and CuZn SOD were present, however no Fe SOD was found in Peridinium . One of three isoenzymes of Mn SOD showed marked differential regulation of activity under stress. An increase in the quantity of the 32‐kDa Mn SOD polypeptide during the bloom was found to be unrelated to senescence; it was assumed that this polypeptide was induced by stress. Thus, SOD in Peridinium undergoes physiological and molecular acclimation to seasonal environmental changes. When Peridinium was exposed to various O 2 and CO 2 concentrations in culture, CuZn SOD significantly increased under high C0 2 concentrations and normoxic conditions (20% O 2 ). However, at high irradiances, Peridinium cultures exposed to low and high CO 2 concentrations also had similar CuZn SOD activity. It was concluded that stressful irradiance is the overriding cause of increased SOD activity in both lake samples and in cultures of Peridinium .