Premium
Senescence‐related changes in the antioxidant status of ginkgo and birch leaves during autumn yellowing
Author(s) -
Kukavica Biljana,
Jovanovic Sonja Veljovic
Publication year - 2004
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.1399-3054.2004.00410.x
Subject(s) - catalase , senescence , apx , peroxidase , superoxide dismutase , antioxidant , ginkgo , chlorophyll , ascorbic acid , botany , biology , oxidative stress , chemistry , biochemistry , horticulture , enzyme , microbiology and biotechnology
The antioxidant status of birch and ginkgo leaves during autumnal senescence was characterized by the activities of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and superoxide dismutase (SOD). The contents of leaf H 2 O 2 and ascorbate were used as indicators of oxidative stress. Degradation of chlorophyll (chl) during natural senescence was not accompanied either by an increase of H 2 O 2 or by a decrease of reduced ascorbate. A transient decrease of reduced ascorbate in ginkgo and birch leaves in early senescence was accompanied by CAT inactivation. The activity of ionically‐bound PODs was stimulated in late senescence in both species, when more than 30% of chl was degraded. Induction of MnSOD in both species and new isoforms of CuZnSOD in birch in late senescence was accompanied by the disappearance of other CuZnSOD isoforms in birch and FeSOD in ginkgo. The role of antioxidative enzymes in keeping ascorbate reduced and endogenous H 2 O 2 at low levels in senescent leaves of deciduous trees was discussed.