INVESTIGADORES
VILLAFAÑE virginia Estela
artículos
Título:
Solar UVR-induced DNA damage and inhibition of photosynthesis in phytoplankton from Andean lakes of Argentina
Autor/es:
VIRGINIA ESTELA VILLAFAÑE; ANITA G J BUMA; PETER BOELEN; E WALTER HELBLING
Revista:
ARCHIV FUR HYDROBIOLOGIE
Editorial:
E. Schweizerbart'sch Verlagsbuchhandlung
Referencias:
Lugar: Sttutgart; Año: 2004 vol. 161 p. 245 - 266
ISSN:
0003-9136
Resumen:
During
January 1999 studies were carried out in temperate lakes of the Andean region
of Argentina (41°S, 71°W) to determine the short-term effects of solar
ultraviolet radiation (UVR, 280-400 nm) upon natural phytoplankton assemblages.
Organisms from one clear (Lake Moreno) and two opaque lakes (Morenito and El Trébol)
were exposed to different radiation regimes to assess photosynthesis inhibition
and cyclobutane pyrimidine dimers (CPDs) accumulation / repair. UV-B caused significant DNA damage in
organisms from opaque lakes, especially those from Lake Morenito. Organisms
from the clear Lake Moreno, on the other hand, presented lower CPDs
accumulation rates. UV-B had relatively
low effects inhibiting photosynthesis in these opaque lakes (2 and 9.5%, for
lakes Morenito and El Trébol, respectively) and most of the inhibition was due
to UV-A (75 and 71% inhibition for lakes Morenito and El Trébol,
respectively). In Lake Moreno, photosynthetic inhibition was 35 and 15% for UV-A
and UV-B, respectively. A number of
causes seem to account for the different responses observed among phytoplankton
assemblages, being one the most important the underwater radiation field and
hence the light acclimation history of cells.
In addition, factors such as differences in the type and effectiveness
of the strategy used by the organisms to cope with solar UVR, as well as
differences in the size structure and taxonomic composition of the community
are also important at the time to evaluate the overall impact of solar UVR in
these lakes.