Photoreactivation of far U.V. damage in the dinoflagellate Peridinium cinctum

• Published in: Environmental and experimental botany 1981-01, Vol.21 (1), p.121-125
• Main Authors: Hayhome, B.A., Brei, T., Tuttle, R.C.
• Format: Article
• Language: English
• Subjects: Algae
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/0098-8472(81)90017-4

The inactivating effect of far u.v. on the photosynthetic freshwater dinoflagellate Peridinium cinctum is substantially reduced by exposure to visible light immediately after u.v. irradiation. When u.v.-irradiated cells are held in the dark at 20°C before exposure to visible light, photoreversibility is progressively lost. The observation that acriflavine increases the loss of photoreversibility suggests that the decrease in photoreactivation is caused by decay of photoreactivating enzyme or by inhibition of new photoreactivating enzyme synthesis. However, when u.v.-irradiated cells are held in the dark at 4°C before exposure to visible light, photoreversibility is increased over that obtained by immediate exposure to visible light after u.v. irradiation. This suggests that photoreactivating enzyme decays less rapidly at 4°C and that excision functions may also be involved in recovery from far u.v. inactivation. These results provide the first evidence for photoreactivation in a dinoflagellate.