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Lipoxygenase‐mediated production of superoxide anion in senescing plant tissue
Author(s) -
Lynch Daniel V.,
Thompson John E.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)81057-1
Subject(s) - superoxide , lipoxygenase , chemistry , biochemistry , enzyme , cytosol , arachidonate 5 lipoxygenase , substrate (aquarium) , microsome , senescence , biology , microbiology and biotechnology , arachidonic acid , ecology
Lipoxygenase activity and superoxide (O .− 2 ) production by microsomal membranes and cytosol from bean cotyledons increased in parallel as senescence progressed. Superoxide production was heat denaturable and dependent on the availability of linoleate, the substrate for lipoxygenase. The specific inhibitor of lipoxygenase, U28938, caused a parallel reduction in enzyme activity and the formation of O − 2 . These observations demonstrate that lipoxygenase activity mediates the formation of superoxide anion, and support the contention that membrane senescence is attributable to a sequence of reactions in which lipasederived fatty acids are utilized by lipoxygenase to generate O − 2 and hydroperoxides.