Heat-evolved microalgal symbionts increase coral bleaching tolerance

P. Buerger*, C. Alvarez-Roa, C. W. Coppin, S. L. Pearce, L. J. Chakravarti, J. G. Oakeshott, O. R. Edwards, M. J. H. van Oppen*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

116 Citations (Scopus)
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Coral reefs worldwide are suffering mass mortalities from marine heat waves. With the aim of enhancing coral bleaching tolerance, we evolved 10 clonal strains of a common coral microalgal endosymbiont at elevated temperatures (31°C) for 4 years in the laboratory. All 10 heat-evolved strains had expanded their thermal tolerance in vitro following laboratory evolution. After reintroduction into coral host larvae, 3 of the 10 heat-evolved endosymbionts also increased the holobionts’ bleaching tolerance. Although lower levels of secreted reactive oxygen species (ROS) accompanied thermal tolerance of the heat-evolved algae, reduced ROS secretion alone did not predict thermal tolerance in symbiosis. The more tolerant symbiosis exhibited additional higher constitutive expression of algal carbon fixation genes and coral heat tolerance genes. These findings demonstrate that coral stock with enhanced climate resilience can be developed through ex hospite laboratory evolution of their microalgal endosymbionts.
Original languageEnglish
Article numbereaba2498
Number of pages8
JournalScience Advances
Issue number20
Publication statusPublished - 13 May 2020
Externally publishedYes


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