Marine Ecology Progress Series | |
Relative sensitivity of DNA and photosystem II in Ulva intestinalis (Chlorophyta) under natural solar irradiation | |
Lars Nichelmann1  Frauke Pescheck1  Hanna Campen1  Wolfgang Bilger1  | |
关键词: Diel cycle; DNA damage; Intertidal zone; Long-term data; Photosynthetic efficiency; Ultraviolet radiation; Sunlight; Ulva intestinalis; | |
DOI : 10.3354/meps11802 | |
学科分类:海洋学与技术 | |
来源: Inter-Research | |
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【 摘 要 】
ABSTRACT: High intensities of sunlight can result in DNA and photosystem II (PSII) damage. However, the relative sensitivity of both these targets under natural sunlight and especially over a long period has not been studied in algae so far. Although DNA damage is highly specifically induced by ultraviolet-B radiation (UVB, 280-315 nm), PSII is inactivated by a broad spectrum. The green macroalga Ulva intestinalis is an appropriate and interesting study organism with which to investigate the relative importance of the 2 different targets of sunlight because this alga contains no UV-screening protective pigments, although it is exposed to strong solar irradiation in its natural habitat. This entails a high risk of DNA damage. Therefore, diel time courses and long‑term development of DNA damage and the optimal quantum yield of PSII (Fv/Fm) were studied in situ. Fv/Fm was extremely reduced at noon, but a fast recovery was observed in the afternoon. As dark-adapted basal fluorescence (Fo) of PSII was substantially decreased during the day, non-photochemical quenching is suggested to be a key photoprotective strategy in U. intestinalis. In contrast, even in samples with strongly reduced Fv/Fm, only very low DNA damage was found, irrespective of the accumulated UVB dose. We propose that efficient photoreactivation driven by natural sunlight balances the induction of dimers. This leads to a higher UVB tolerance of DNA than that observed in algae under experimental UVB irradition. In this field study, U. intestinalis suffered more from photoinhibition than from DNA damage.
【 授权许可】
Unknown
【 预 览 】
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RO201912010137043ZK.pdf | 8KB | ![]() |