Intraspecific and interspecific variation in thermotolerance and photoacclimation in Symbiodinium dinoflagellates
Por:
Díaz-Almeyda E.M., Prada C., Ohdera A.H., Moran H., Civitello D.J., Iglesias-Prieto R., Carlo T.A., Lajeunesse T.C., Medina M.
Publicada:
1 ene 2017
Resumen:
Light and temperature are major drivers in the ecology and biogeography of symbiotic dinoflagellates living in corals and other cnidarians. We examined variations in physiology among 11 strains comprising five species of clade A Symbiodinium. We grew cultures at 26oC (control) and 32oC (high temperature) over a duration of 18 days while measuring growth and photochemical efficiency (Fv/Fm). Responses to thermal stress ranged from susceptible to tolerant across species and strains. Most strains exhibited a decrease in cell densities and Fv/Fm when grown at 32oC. Tolerance to high temperature (T32) was calculated for all strains, ranging from 0 (unable to survive at high temperature) to 1 (able survive at high temperature). There was substantial variation in thermotolerance across species and among strains. One strain had a T32 close to 1, indicating that growth was not reduced at 32oC for only this one strain. To evaluate the combined effect of temperature and light on physiological stress, we selected three strains with different levels of thermotolerance (tolerant, intermediate and susceptible) and grew them under five different light intensities (65, 80, 100, 240 and 443 µmol quanta m-2 s-1) at 26 and 32oC. High irradiance exacerbated the effect of high temperature, particularly in strains from thermally sensitive species. This work further supports the recognition that broad physiological differences exist not only among species within Symbiodinium clades, but also among strains within species demonstrating that thermotolerance varies widely between species and among strains within species. © 2017 The Author(s) Published by the Royal Society. All rights reserved.
Filiaciones:
Díaz-Almeyda E.M.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Department of Biology, Emory University, Atlanta, GA, United States
Prada C.:
Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States
Ohdera A.H.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Moran H.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Civitello D.J.:
Department of Biology, Emory University, Atlanta, GA, United States
Iglesias-Prieto R.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Carlo T.A.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Lajeunesse T.C.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
Medina M.:
Department of Biology, The Pennsylvania State University, State College, PA, United States
|