Meeting Abstract

P1.25  Tuesday, Jan. 4  Corals need their vitamin C too: Effect of antioxidants on the bleaching response TWUM, Danielle; NIETO-ROSAS, Ishaira*; SCHWARZ, Jodi; Vassar College; Vassar College; Vassar College datwum@vassar.edu

Coral reefs are complex and fragile communities that serve as a source of food and habitat for marine organisms. Most corals form a mutualistic symbiosis with unicellular dinoflagellate symbionts, in which the relationship is founded on reciprocal nutritional interactions. The coral supplies the symbiont with inorganic waste materials like nitrogen, phosphorus and carbon and the symbiont in turn transforms these products into photosynthates and transfers a portion back to the host coral. When exposed to elevated temperatures, corals respond by “bleaching,” which is a breakdown in the symbiotic relationship. Evidence suggests that thermal stress induces a strong bleaching response by disrupting the photosynthetic functioning of the symbiont, producing an excess of reactive oxygen species (ROS). The presence of ROS triggers an oxidative stress response in the host, leading to cellular damage. Therefore, bleaching is the end result of an oxidative stress response in corals. We hypothesized that exposure to an antioxidant compound should mitigate or reduce the severity of bleaching. We examined this relationship using the sea anemone Aiptasia pallida, which is an ideal model system for studying bleaching. Anemones exposed to thermal stress while in the presence of 1uM, 5uM, and 10uM concentrations of the anti-oxidant Naringin dihydrochalcone experienced a significant reduction in the severity of bleaching relative to anemone exposed directly to thermal stress without anti-oxidant treatment.