Acclimation and adaptation to irradiance in symbiotic dinoflagellates. I. Responses of the photosynthetic unit to changes in photon flux density
Year: 1994
Type: article
Abstract: The photosynthetic responses to variations in photon flux density were determined for Symbiodinium microadriaticum, the symbiont of the Caribbean jellyfish Cassiopeia xamachana, S. kawagutii, the symbiont of the Indo-Pacific stony coral Montipora verrucosa, and S. pilosum, the symbiont of the Caribbean zoanthld Zoanthus sociatus.Photosynthetic responses were characterized in terms of cellular pigment content, photosynthesis versus irradiance (P-I) relationships, and number and size of the photosynthetic unit (PSU).Analyses of the responses under 2 Light regimes of 40 and 250 p 0 1 quanta m-' S-' indicate that: (1) the 3 different species cultured under identical conditions possess different photosynthetic characteristics; (2) the 3 species acclimate to low photon flux density by simultaneously increasing the number and size of their PSU;(3) PSU characteristics were not correlated with the parameters of their respechve P-lcurves; (4) the 3 species analyzed have different photoacclimatory capabilities which can be correlated with their respective ecological distribution as endosymbionts.As different species demonstrate characteristic responses, photo-acclunatory adjustment in symbiotic dinoflagellates may be under genetic constraints, and thus may represent photo-adaptation (sensu 0. Bjorkman).As a whole, the results suggest that symbiont photo-adaptation may constitute an important axis of niche diversification for the intact associations.
Source: Marine Ecology Progress Series
DOI: 10.3354/meps113163
Authors: R Iglesias-Prieto, RK Trench
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Life below water
Open Access status: bronze
OpenAlex ID: W2050419417