Hydrogen peroxide formation in cultured rose cells in response to UV‐C radiation
1990; Wiley; Volume: 78; Issue: 2 Linguagem: Inglês
10.1111/j.1399-3054.1990.tb02088.x
ISSN1399-3054
AutoresTerence M. Murphy, Alfredo J. Huerta,
Tópico(s)Genomics, phytochemicals, and oxidative stress
ResumoSuspension‐cultured rose ( Rosa damascena Mill. cv. Gloire de Guilan) cells irradiated with UV‐C (254 nm. 558 J m −2 ) showed a transient production of H 2 O 2 as measured by chemiluminescence of luminol in the presence of peroxidase (EC 1.1 1.1.7). The peak concentration of H 2 O 2 , which occurred at about 60–90 min after irradiation, was 8–9 μ M . The time course for the appearance of H 2 O 2 matched that for UV–induced K + efflux. Treatments that inhibited the UV‐induced efflux of K + , including heat and overnight incubation with cycloheximide and diethylmaleate, also inhibited the appearance of H 2 O 2 . The converse was not always true, since catalase (EC 1.11.1.6. and salicylhydroxamic acid, which inhibited luminescence, did not stop K + efflux. We conclude that H 2 O 2 synthesis depends on K + efflux. Because H 2 .O 2 in the extracellular space is required for lignin synthesis in many plant tissues, we suggest that the UV–stimulated production of H 2 O 2 is an integral part of a defensive lignin synthesis.
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