title: Species-specific control of external superoxide levels by the coral holobiont during a natural bleaching event.
abstract: The reactive oxygen species superoxide (O2·-) is both beneficial and detrimental to life. Within corals, superoxide may contribute to pathogen resistance but also bleaching, the loss of essential algal symbionts. Yet, the role of superoxide in coral health and physiology is not completely understood owing to a lack of direct in situ observations. By conducting field measurements of superoxide produced by corals during a bleaching event, we show substantial species-specific variation in external superoxide levels, which reflect the balance of production and degradation processes. Extracellular superoxide concentrations are independent of light, algal symbiont abundance and bleaching status, but depend on coral species and bacterial community composition. Furthermore, coral-derived superoxide concentrations ranged from levels below bulk seawater up to ∼120 nM, some of the highest superoxide concentrations observed in marine systems. Overall, these results unveil the ability of corals and/or their microbiomes to regulate superoxide in their immediate surroundings, which suggests species-specific roles of superoxide in coral health and physiology.
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.|Skidaway Institute of Oceanography, Department of Marine Sciences, University of Georgia, 10 Ocean Science Circle, Savannah, Georgia 31411, USA.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Diaz
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Hansel
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Apprill
authors.affiliation: Department of Chemistry, Imperial College London, Imperial College Road, London SW7 2AZ, UK.
authors.forename: Caterina
authors.initials: C
authors.lastname: Brighi
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.|MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Tianjin 300350, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Weber
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.|School for the Environment, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: McNally
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, Massachusetts 02543, USA.
authors.forename: Liping
authors.initials: L
authors.lastname: Xun
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism* / Q000382:microbiology; D002940:Circadian Rhythm; D004141:Dinoflagellida / Q000378:metabolism*; D007814:Larva / Q000502:physiology; D064307:Microbiota; D010858:Pigmentation; D013045:Species Specificity; D013481:Superoxides / Q000378:metabolism*; D013559:Symbiosis
chemical_list: D013481:Superoxides