ICU Student Receives Poster Presentation Award from the Japanese Coral Reef Society (JCRS)
Update: December 11, 2020
Ms. Reimi Terayama (major: Biology), a 4th year student at ICU's College of Liberal Arts, was awarded the Poster Presentation Award at the 23rd annual meeting of the Japanese Coral Reef Society held online from November 21st to 23rd.
Ms. Terayama's presentation, based on her research on the mechanism of the combined damage in corals caused by heat and light, was highly praised as a study that is expected to lead to future coral conservation measures.
Photoinhibition as a strategy for corals to mitigate heat stress
Coral reefs are threatened by the rising seawater temperature due to global warming. Under high temperature stress, the symbiotic between the coral host and their symbiont, zooxanthellae, is broken which leads to the loss of zooxanthellae, a phenomenon often referred to as coral bleaching.
As the rubisco enzyme gets degraded by the high temperature, the excess flow of energy that comes from the light absorbed by the photosynthetic systems, causes the production of harmful reactive oxygen species (ROS). Photoinhibition, the decrease of photochemical efficiency occurs under high irradiance. Photoinhibition reduce the conversion of light energy into chemical energy. Here we hypothesize that under heat stress, increased photoinhibition further reduces the amount of energy that reaches damaged Rubisco and thus prevent ROS production.
In my experiment, I measured gross photosynthesis and photochemical efficiency. Both gross photosynthesis and photoinhibition increased with irradiance. Furthermore, under heat stress, photoinhibition was higher compared to under control temperature, reducing photosynthesis (as measured by oxygen production), and therefore the energy flow into potentially damaged Rubisco. These results suggest that photoinhibition can be a strategy for corals to mitigate heat stress.
Comment on receiving the award
It is a great honor for me to receive an award from JCRS!
I am currently conducting my undergraduate research at the Shimoda Marine Research Center, University of Tsukuba, thanks to a partnership between the University of Tsukuba and the International Christian University. I was inspired to study corals during my days at the ICU's scuba diving club. While I was enjoying beautiful beaches, I thought that it would be nice if my research could help corals in facing increasing threats from anthropogenic stresses.
I am pleased I could study in such favorable environment. The experiences and knowledge I acquired while studying and conducting research at ICU and Shimoda will be unforgettable.
I would like to express my sincere appreciation to my supervisors, Assist. Prof. Sylvain Agostini and Prof. Tsuyoshi Mizoguchi, and to all my collaborators.