Variations in Reactive Oxygen Release and Antioxidant Activity in Multiple Symbiodinium Types in Response to Elevated Temperature
- 753 Downloads
As ocean temperatures rise, investigations into what the physiological effects will be on the symbiotic microalga Symbiodinium, and how these may play into the cnidarian bleaching response, have highlighted the contribution of reactive oxygen species (ROS). Previous studies have laid this groundwork using a limited number of Symbiodinium phylotypes, and so this study aims to expand this understanding by exploring the effects of sub-lethal elevated temperatures on the physiological response of seven genetically distinct types of Symbiodinium, including A1, B1, B2, C1, D, E1, and F2. The production of ROS (at 26 °C, 29 °C, 30 °C, and 31 °C) and activity of the antioxidants catalase (CAT) and superoxide dismutase (SOD) (at 26 °C and 31 °C) were measured as indicators of sensitivity or tolerance to heat stress. Symbiodinium types B1 and C1 were the most thermally sensitive, with C1 producing the highest amount of ROS at elevated temperatures. Types A1 and F2 were tolerant, having no increase in ROS production, and were the only types to increase both CAT and SOD activity with temperature stress. Type B2 had decreased ROS production and elevation of CAT activity, while type E1 had decreased levels of ROS production at elevated temperatures. Type D was the only Symbiodinium type to remain unaffected by elevated temperatures. These results are consistent with previous findings of relative sensitivity or tolerance to elevated temperatures, specifically with regards to types A1, B1, and F2. The inclusion of types B2, C1, D, and E1 provides further new evidence of how types differ in their thermal responses, suggesting differing mechanisms exist in the Symbiodnium response to higher temperature and highlighting the importance of establishing symbiont identity when exploring the response of intact associations to this type of stress.
KeywordsReactive Oxygen Species Internal Transcribe Spacer Reactive Oxygen Species Production Increase Reactive Oxygen Species Production High Reactive Oxygen Species
Internal transcribed spacer-2
Reactive oxygen species
The authors would like to acknowledge funding from UTA start-up funds, UTA Research Enhancement Program and NSF # 1017458 (to LDM). The authors would like to thank Todd LaJeunesse (Pennsylvania State University) and Scott Santos (Auburn University) for generously providing Symbiodinium cultures, and James Drake, Regina Roy and Whitney T. Mann (University of Texas at Arlington) for experimental support. Comments by David J. Suggett, Robert F. McMahon, Christian L. Cox, Caroline V. Palmer, Whitney T. Mann and two anonymous reviewers have significantly improved this manuscript.
- 4.Huertas IE, Rouco M, Lopez-Rodas V, Costas E (2011) Warming will affect phytoplankton differently: evidence through a mechanistic approach. Proc Roy Soc B Biol Sci. doi: 10.1098/rspb.2011.0160
- 6.Muscatine L (1973) Nutrition of corals. In: Jones OA, Endean R (eds) Biology and geology of coral reefs, vol 2. Academic, New York, pp 77–115Google Scholar
- 13.Veron JEN, Hoegh-Guldberg O, Lenton TM, Lough JM, Obura DO, Pearce-Kelly P, Sheppard CRC, Spalding M, Stafford-Smith MG, Rogers AD (2009) The coral reef crisis: the critical importance of <350 ppm CO2. Mar Pollut Bull 58(10):1428–1436. doi: 10.1016/J.Marpolbul.2009.09.009 PubMedCrossRefGoogle Scholar
- 15.Wilkinson CR (ed) (2004) Status of the coral reefs of the world: 2004. Global Coral Reef Monitoring Network and Australian Institute of Marine Science, Townsville, Australia, p 557Google Scholar
- 16.van Oppen MJH, Lough JM (eds) (2009) Coral bleaching—patterns, processes, causes and consequences, vol 205. Ecological Studies, Springer-VerlagGoogle Scholar
- 17.Carpenter KE, Abrar M, Aeby G, Aronson RB, Banks S, Bruckner A, Chiriboga A, Cortes J, Delbeek JC, DeVantier L, Edgar GJ, Edwards AJ, Fenner D, Guzman HM, Hoeksema BW, Hodgson G, Johan O, Licuanan WY, Livingstone SR, Lovell ER, Moore JA, Obura DO, Ochavillo D, Polidoro BA, Precht WF, Quibilan MC, Reboton C, Richards ZT, Rogers AD, Sanciangco J, Sheppard A, Sheppard C, Smith J, Stuart S, Turak E, Veron JEN, Wallace C, Weil E, Wood E (2008) One-third of reef-building corals face elevated extinction risk from climate change and local impacts. Science 321(5888):560–563. doi: 10.1126/Science.1159196 PubMedCrossRefGoogle Scholar
- 39.McBride BB, Muller-Parker G, Jakobsen HH (2009) Low thermal limit of growth rate of Symbiodinium californium (Dinophyta) in culture may restrict the symbiont to southern populations of its host anemones (Anthopleura spp.; Anthozoa, Cnidaria). J Phycol 45(4):855–863. doi: 10.1111/J.1529-8817.2009.00716.X CrossRefGoogle Scholar
- 41.Freudenthal HD (1962) Symbiodinium gen. Nov. and Symbiodinium microadriaticum sp. nov., a zooxanthella: taxonomy, life cycle, and morphology. J Protozool 9:45–52Google Scholar
- 48.Banaszak AT, Santos MG, LaJeunesse TC, Lesser MP (2006) The distribution of mycosporine-like amino acids (MAAs) and the phylogenetic identity of symbiotic dinoflagellates in cnidarian hosts from the Mexican Caribbean. J Exp Mar Biol Ecol 337(2):131–146. doi: 10.1016/J.Jembe.2006.06.014 CrossRefGoogle Scholar