UV-B effects on filamentous alga Zygnema strain (EEL201) from Antarctica

• Main Author: Prieto-Amador, Marina
• Format: Article in Journal/Newspaper
• Language: English
• Published: Masaryk Univerzity 2016
• Subjects: James Ross Island; chlorophyll fluorescence parameters; photosystem II; photoinhibition; absorption spectrum; Arctic; Ross Island; Antarc*; Antarctica
• Online Access: http://journals.muni.cz/CPR/article/view/12885

Filamentous alga Zygnema sp. is frequently found in extreme polar environments with freshwater availability for at least part of summer season. In such habitats, Zygnema might be exposed to several stress factors, like freeze, desiccation and high irradiation levels. This study investigated the effect of UV-B on primary photosynthetic processes in Zygnema sp. (EEL201 strain) from Antarctica. Samples were cultivated in liquid medium and exposed to supplemental UV-B (1.4 W m-2) for 6 h. During the UV-B treatment and following recovery, the changes in chlorophyll fluorescence paramaters caused UV-B were measured. Negative effects on FV/FM and FPSII were found after 6 h treatment with only limited recovery in dark. The only parameter that recovered was photochemical quenching (qP) indicating a potential to restore photosynthesis in the reaction centres that were not damaged by UV-B treatment. However, the share on damaged RC PS II was much higher compared to those showing the recovery. Thus, the effect of short-term supplemental 1.4 W m-2 UV-B light was considered heavy causing substantial damages to PS II. These results provide insights on the effects of UV-B light onZygnemasp. that can help in the interpretation of response mechanisms of Arctic algae to radiation.