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Leaf senescence and lipid peroxidation: Effects of some phytohormones, and scavengers of free radicals and singlet oxygen
Author(s) -
Dhindsa Rajinder S.,
PlumbDhindsa Pamela L.,
Reid David M.
Publication year - 1982
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.1399-3054.1982.tb04539.x
Subject(s) - lipid peroxidation , catalase , superoxide dismutase , avena , senescence , chemistry , biochemistry , antioxidant , biology , botany , microbiology and biotechnology
During in vitro senescence (chlorophyll loss) of oat ( Avena sativa L. cv. Victory) leaf segments and of leaf discs of Rumex obtusifolius L, the activity of catalase decreases and lipid peroxidation increases. The activity of superoxide dismutase (SOD) decreases in Rumex leaf discs but changes little in oat leaf segments. Kinetin treatment of oat leaf segments, and GA 3 treatment of Rumex leaf discs, inhibit decline in the enzyme activities and increase in the level of lipid peroxidation and strongly inhibit senescence. In either leaf tissue a treatment with ethanol or vitamin E (scavengers of free radicals) or with diphenylisobenzofuran (scavenger of singlet oxygen) results in a strong inhibition of lipid peroxidation and senescence, but does not affect much the decline in the SOD and catalase activities. It is concluded that, i) senscence‐associated lipid peroxidation is induced by free radicals and singlet oxygen; and, ii) kinetin and GA 3 inhibit senescence mainly by a modulation of lipid peroxidation through maintaining high levels of such cellular scavengers as SOD and catalase.