Oxidative stress in cucumber (Cucumis sativus L) seedlings treated with acifluorfen.
Indian J Biochem Biophys
;
2000 Dec; 37(6): 498-505
Artigo
em Inglês
| IMSEAR
| ID: sea-28586
ABSTRACT
Treatment of diphenyl ether herbicide acifluorfen-Na (AF-Na) to intact cucumber (Cucumis sativus L cv Poinsette) seedlings induced overaccumulation of protoporphyrin IX in light (75 mumole m-2 s-1). The extra-plastidic protoporphyrin IX accumulated during the light exposure disappeared within two hours of transfer of acifluorofen-treated seedlings to darkness. The dark disappearance was due to re-entry of migrated protoporphyrin IX into the plastid and its subsequent conversion to protochlorophyllide. In light, protoporphyrin IX acted as a photosensitizer and caused generation of active oxygen species. The latter caused damage to the cellular membranes by peroxidation of membrane lipids that resulted in production of malondialdehyde. Damage to the plastidic membranes resulted in damage to photosystem I and photosystem II reactions. Dark-incubation of herbicide-sprayed plants before their exposure to light enhanced photodynamic damage due to diffusion of the herbicide to the site of action. Compared to control, in treated samples the cation-induced increases in variable fluorescence/maximum fluorescence ratio and increase in photosystem II activity was lower due to reduced grana stacking in herbicide-treated and light-exposed plants.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
Protoporfirinas
/
Estresse Oxidativo
/
Cucumis sativus
/
Herbicidas
/
Nitrobenzoatos
Idioma:
Inglês
Revista:
Indian J Biochem Biophys
Ano de publicação:
2000
Tipo de documento:
Artigo
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