Abstract
A fifteen-day outdoor cultivation with the UV-B sensitive and the resistant microalgal species was carried out during mid-September to early October 1995 in order to verify laboratory-identified UV-B sensitivity/tolerance of the photosynthetic apparatus in these organisms, in the field. Outdoor light conditions during the experiment were basically characterized by a regular diurnal change superimposed by unequal daily variation of PAR and ambient UV-B irradiation. The maximum value of 370 W m-2 of PAR and 1.4 W m-2 of unweighted UV-B irradiation were monitored during midday sunny days. Both the UV-B sensitive and the -resistant species suffered from exposure to the solar irradiation as demonstrated by impairment of photosynthesis (photosynthetic O2 evolution capacity, Chl a fluorescence parameters and pigments content) and inhibition of the daily growth rate. Higher UV-B susceptibility was consistently observed in the lab-identified UV-B sensitive species, than its resistant counterparts. Outdoor exposure-caused impairment of photosynthesis was due to not only the UV-B-induced damage of photosynthetic apparatus but also the visible light-induced photoinhibition. Our results suggest that the protective mechanism that microalgae employ to counteract enhanced UV-B stress function both in the laboratory and in the field.
Original language | English |
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Pages (from-to) | 54-62 |
Number of pages | 9 |
Journal | Journal of Plant Physiology |
Volume | 155 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1999 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the grants 202/94/0457 and 202/951 1043 of the Grant Agency of the Czech Republic. The microalgal species were kindly provided by ]aromir Lukavsky and Filip Lederer at the Collection of Aurotrophic Microorganisms, Botanical Institute, AVCR, Trebon.
Keywords
- Chl fluorescence
- Microalgae
- Oxygen evolution
- Photosynthesis
- Solar irradiation
- UV-B sensitivity
- Ultraviolet irradiation
ASJC Scopus subject areas
- Physiology
- Agronomy and Crop Science
- Plant Science