Photosynthetic UV stress tolerance of the Antarctic snow alga Chlorella sp. modified by enhanced temperature?
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Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sociedad de Biología de Chile
Abstract
Background: Photosynthetic characteristics and the effect of UV radiation and elevated temperature measured
were studied in Chlorella sp. isolated from a snow microalgal community at King George Island, Maritime Antarctica
through the chlorophyll florescence (rapid light curves and maximum quantum yield, respectively). The
environmental context was monitored through measurements of spectral depth profiles of solar radiation (down to
40 cm) in the snowpack as well as a through continuous recording of temperature and PAR using dataloggers
located at different depths (0–30 cm) within the snow column.
Results: The photochemistry of Chlorella sp. was affected by UV radiation in a 12-h laboratory exposure under all
studied temperatures (5, 10, 15, 20 °C): the algae exposed to PAR + UV-A radiation were inhibited by 5.8 % whilst PAR
+ UV-A + UV-B radiation decreased Fv/Fm by 15.8 %. In both treatments the 12-h recovery after UV exposure was
almost complete (80–100 %). Electron transport based P-I curve parameters maximal electron transport rate (ETRmax),
photosynthetic efficiency (α) and the saturating irradiance (Ek) no varied in response to different temperatures.
Conclusions: Results revealed that Chlorella sp. not only shows high photosynthetic efficiency at ambient conditions,
but also exhibits tolerance to solar radiation under higher temperatures and possessing a capacity for recovery after
inhibition of photosynthesis by UV radiation.
Description
BioMed Central
Keywords
Ciencia, Snow algae, Photosynthesis, UV radiation, Temperature
Citation
Rivas et al. Revista Chilena de Historia Natural (2016) 89:7