INVESTIGADORES
VILLAFAÑE virginia Estela
artículos
Título:
Ocean acidification alters the photosynthetic responses of the coccolithophorid Gephyrocapsa oceanica to fluctuating visible and UV radiation
Autor/es:
JIN, P.; GAO, K; VILLAFAÑE, V. E.; CAMPBELL, D. A.; HELBLING, E. W.
Revista:
PLANT PHYSIOLOGY.
Editorial:
AMER SOC PLANT BIOLOGISTS
Referencias:
Lugar: Rockville; Año: 2013 vol. 162 p. 2084 - 2094
ISSN:
0032-0889
Resumen:
Mixing of seawater
subjects phytoplankton to fluctuations in photosynthetically active radiation
(400?700 nm) and ultraviolet radiation (UVR; 280?400 nm). These irradiance
fluctuations are now superimposed upon ocean acidification and thinning of the
upper mixing layer through stratification, which alters mixing regimes.
Therefore, we examined the photosynthetic carbon fixation and photochemical
performance of a coccolithophore, Gephyrocapsa
oceanica, grown under high, future (1,000 µatm) and low, current (390 µatm)
CO2 levels, under regimes of fluctuating irradiances with or without
UVR. Under both CO2 levels, fluctuating irradiances, as compared
with constant irradiance, led to lower nonphotochemical quenching and less
UVR-induced inhibition of carbon fixation and photosystem II electron
transport. The cells grown under high CO2 showed a lower
photosynthetic carbon fixation rate but lower nonphotochemical quenching and
less ultraviolet B (280?315 nm)-induced inhibition. Ultraviolet A (315?400 nm)
led to less enhancement of the photosynthetic carbon fixation in the high-CO2-grown
cells under fluctuating irradiance. Our data suggest that ocean acidification
and fast mixing or fluctuation of solar radiation will act synergistically to
lower carbon fixation by G. oceanica,
although ocean acidification may decrease ultraviolet B-related photochemical
inhibition.