Extra high superoxide dismutase in host tissue is associated with improving bleaching resistance in “thermal adapted” and Durusdinium trenchii -associating coral

PeerJ

article

Jih-Terng Wang¹  Yi-Ting Wang¹  Chaolun Allen Chen²  Pei-Jei Meng³  Kwee Siong Tew⁴  Pei-Wen Chiang²  Sen-Lin Tang² 

[1]Department of Oceanography, National Sun Yat-Sen University

[2]Biodiversity Research Center

[3]General Education Center, National Dong Hwa University

[4]National Museum of Marine Biology and Aquarium

[5]Institute of Marine Biodiversity and Evolution, National Dong Hwa University

关键词: Coral bleaching;    Superoxide dismutase;    Catalase;    Symbiodiniaceae algae;    Endozoicomonas;   

DOI  :  10.7717/peerj.12746

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Global warming threatens reef-building corals with large-scale bleaching events; therefore, it is important to discover potential adaptive capabilities for increasing their temperature resistance before it is too late. This study presents two coral species (Platygyra verweyi and Isopora palifera) surviving on a reef having regular hot water influxes via a nearby nuclear power plant that exhibited completely different bleaching susceptibilities to thermal stress, even though both species shared several so-called “winner” characteristics (e.g., containing Durusdinium trenchii, thick tissue, etc.). During acute heating treatment, algal density did not decline in P. verweyi corals within three days of being directly transferred from 25 to 31 °C; however, the same treatment caused I. palifera to lose < 70% of its algal symbionts within 24 h. The most distinctive feature between the two coral species was an overwhelmingly higher constitutive superoxide dismutase (ca. 10-fold) and catalase (ca. 3-fold) in P. verweyi over I. palifera. Moreover, P. verweyi also contained significantly higher saturated and lower mono-unsaturated fatty acids, especially a long-chain saturated fatty acid (C22:0), than I. palifera, and was consistently associated with the symbiotic bacteria Endozoicomonas, which was not found in I. palifera. However, antibiotic treatment and inoculation tests did not support Endozoicomonas having a direct contribution to thermal resistance. This study highlights that, besides its association with a thermally tolerable algal symbiont, a high level of constitutive antioxidant enzymes in the coral host is crucial for coral survivorship in the more fluctuating and higher temperature environments.

【 授权许可】

CC BY