Thermal tolerance of Symbiodinium and differential stability of photosynthetic membranes

• Main Authors: Ruo-Yi Hong, 洪若譯
• Other Authors: Hong-Nung Chou
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/j965be

碩士 === 國立臺灣大學 === 漁業科學研究所 === 106 === Coral reefs are one of the most biologically diverse and productive ecosystems, and their existence depends on the mutualistic symbiosis between coral and and a single celled dinoflagellate alga; Symbiodinium. The perturbation to this symbiosis could cause coral bleaching; the expulsion or loss of of Symbiodinium from the coral host. Among the various factors of inducing coral bleaching, thermal stress is the wide spread and prominent one. Thermal stress damages the photosynthetic membranes of Symbiodinium and induce oxidative stress by leakage of reactive oxygen species. However, Symbiodinium has high genetic diversity, resulting in their differential physiological performance. For example, the ability to provide photosynthetic products to host, antioxidant capability and thermal susceptibility. In this study, we used maximum photochemical efficiency coupled with short term thermal stress to assess the melting temperature and thermal tolerance of several strains of Symbiodinium. Our results showed that among 3 Symbiodinium types studied, Symbiodinium C1 has the highest melting temperature of photosynthetic membranes at 40.30 ºC. As for the thermal tolerance, Symbiodinium C56a’ showed higher thermal tolerance than Symbiodinium clade D. This study extends our knowledge toward Symbiodinium and their physiological potential and limits under thermal stress.